Keats - Atlas of normal roentgen variants that may simulate disease 9th Ed. [2013]

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Atlas of Normal Roentgen Variants That May Simulate Disease

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Atlas of Normal Roentgen Variants That May Simulate Disease NINTH EDITION

Theodore E. Keats, MD† Formerly, Alumni Professor of Radiology Department of Radiology University of Virginia Health System Charlottesville, Virginia

Mark W. Anderson, MD Harrison Distinguished Teaching Professor of Radiology Chief, Division of Musculoskeletal Radiology Department of Radiology University of Virginia Health System Charlottesville, Virginia

1600 John F. Kennedy Blvd. Ste 1800 Philadelphia, PA 19103-2899

ATLAS OF NORMAL ROENTGEN VARIANTS THAT MAY SIMULATE 978-0-323-07355-4 DISEASE, NINTH EDITION Copyright © 2013 by Saunders, an imprint of Elsevier Inc. Copyright © 2007, 2001, 1996, 1992, 1988, 1979, 1973 by Mosby, an affiliate of Elsevier Inc. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions. This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein).

Notices Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary. Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility. With respect to any drug or pharmaceutical products identified, readers are advised to check the most current information provided (i) on procedures featured or (ii) by the manufacturer of each product to be administered, to verify the recommended dose or formula, the method and duration of administration, and contraindications. It is the responsibility of practitioners, relying on their own experience and knowledge of their patients, to make diagnoses, to determine dosages and the best treatment for each individual patient, and to take all appropriate safety precautions. To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein. Library of Congress Cataloging-in-Publication Data Keats, Theodore E. (Theodore Eliot), 1924–2010. Atlas of normal roentgen variants that may simulate disease / Theodore E. Keats, Mark W. Anderson. — 9th ed. p. ; cm. Includes index. ISBN 978-0-323-07355-4 (hardcover : alk. paper) I. Anderson, Mark W., 1957– II. Title. [DNLM: 1. Radiography—Atlases. 2. Artifacts—Atlases. 3. Diagnostic Errors—Atlases. WN 17] 616.07’572—dc23

Content Strategist: Pamela Hetherington Content Development Manager: Maureen Iannuzzi Publishing Services Manager: Julie Eddy Senior Project Manager: Celeste Clingan Design Direction: Ellen Zanolle

Printed in China Last digit is the print number:  9  8  7  6  5  4  3  2  1

2012007237

Foreword

“He was a man. Take him for all in all. I shall not look upon his like again.” Hamlet (referring to his father)

Since the previous edition of this text was published, the world of radiology lost one of its giants. Theodore Elliot Keats, the personification of a true Virginia gentleman, passed away on December 10, 2010, and just as Hamlet felt about his father, I too have no doubt that we shall not look upon his like again. In addition to being a successful chairman, prolific writer, and world-renowned speaker, Ted was also a consummate clinical radiologist who loved nothing more than teaching a resident at the viewbox, all the while keeping his keen eye out for a new normal variant. Not a week would go by that he didn’t add to his unparalleled collection, and it was his unending curiosity and observational acuity that resulted in this now legendary text. Thankfully, he was able to continue to teach and discover new entities until the week before he died at the age of 85! But beyond all of his professional accomplishments, his awards, and accolades, Ted was a wonderful husband, father, grandfather, colleague, and friend. His warm smile and quick laugh were infectious, and his absence has left a large void in our department as well as in the hearts of those who knew him well. Even so, his presence will live on in those who knew him, and like Gray’s Anatomy and Grant’s Atlas, there will always be a Keats’ Normal Variants. No matter how much our imaging technology changes, the incredible variability of what is “normal” in the human body will not, nor will our efforts to find and catalog new examples to add to this volume. Ted would have wanted it that way.

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Preface PREFACE TO THE NINTH EDITION “. . . can one desire too much of a good thing?” WILLIAM SHAKESPEARE (As You Like It) Over the years, this atlas has become the definitive work on normal roentgen variants and is a lasting testimony to the energy, organization, and endless curiosity of its creator and curator, Ted Keats. With each new edition Ted would add several examples of newly discovered variants or better examples of those already in print, but since the publication of the last edition, we have noticed that we sometimes think twice about lifting it off of the shelf because of its sheer size and weight. Perhaps there really can be too much of a good thing! As a result, you’ll notice that this ninth edition has a very different look and feel. We have again added some new cases to the mix, but we have also carefully gone through and removed

many of the duplicate examples, exceedingly rare entities, or some illustrations that just did not project well. Additionally, because of the increased use of cross-sectional imaging for evaluating the soft tissues, we have removed the chapters dealing with soft tissue variants and made those available online for those who purchase this volume, along with all of the skeletal variants that were removed from the eighth edition. What is left is a more manageable volume that contains the best of the collection and that should provide more than enough variety to warrant its continued presence in the reading room. With Ted’s passing, we’ve entered a new era, but his infectious enthusiasm for this topic lives on, and we will continue the search for normal variation unabated. He would have wanted it that way! Mark W. Anderson

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Preface

PREFACE TO THE EIGHTH EDITION What nature delivers to us is never stale. Because what nature creates has eternity in it. ISAAC BASHEVIS SINGER Nature’s bounty is endless, and our study of normal anatomic variation confirms this. It is this constant variation of anatomy that makes diagnostic radiology such an exciting and challenging occupation. In this edition we present the products of our recent experience and have included CT and MRI amplification of some of these entities. We have also substituted better examples of variants previously presented. In our preface to the last edition, we suggested that since plain film radiography of the skull was becoming passé, it might

behoove us to eliminate this section. Unfortunately, as the art of plain film interpretation of the skull is diminishing, there is a corresponding increase in errors of interpretation, particularly in the overdiagnosis of normal variation. To this end, we have decided to leave this section in place. We are pleased with the continued enthusiastic reception of this work by our colleagues and appreciate the contributions of physicians who have sent us case material for inclusion in this edition. We owe special recognition to our secretary, Denise Johnson, for her help in assembling this edition and to our wives, Patt and Amy, for their interest in and support of this effort. Theodore E. Keats Mark W. Anderson



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PREFACE TO THE SEVENTH EDITION The scientist who collects and catalogs and the child who wanders barefoot through the woods are equally awestruck by the sheer profusion of creatures that populate this planet. PAUL BRAND and PHILIP YANCEY The above quotation states perfectly my awe of the infinite variety with which nature has provided us. Despite my 28 years of gathering normal roentgen anatomic variants, scarcely a day or a week goes by without my finding some variation that I have not recognized previously. Fortunately, most of these are sufficiently obvious that they do not arouse any concern of pathology. Nevertheless, I have still managed to accumulate a large number that do raise suspicion, and these constitute the new additions to this seventh edition. In order to keep the size of the book manageable, I have seriously considered which entities I could reasonably eliminate. I have removed the variants demonstrated by bronchography, since this technique has disappeared, but there is little else that is not still applicable. I am a bit saddened to note that interpretation of conventional radiography of the skull is rapidly becoming a lost art because of the advent of CT.

Perhaps this section might be removed or limited in future editions, but at present I have retained it, since in some less technically sophisticated societies it is still a first line of investigation. With this edition I am introducing my friend and colleague, Dr. Mark W. Anderson, Associate Professor of Radiology here at the University of Virginia, as co-author. Dr. Anderson is an accomplished musculoskeletal radiologist who will help carry on this work. His expertise in CT and MRI will enhance future editions with improved explanatory supplemental studies. Dr. Anderson and I serve as emergency radiologists in our department, and the material from this source will also provide us with additional bone and soft tissue variants for future inclusion. Once again, I wish to express my thanks to the many radiologists in the United States and abroad who have submitted cases for my review. Their interest and gracious permission to include their material in the book is much appreciated. Again, I owe special recognition to my secretary, Patricia West Steele, for many years of loyalty and dedication, and to my wife, Patt, for her long interest in and support of this work. Theodore E. Keats

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PREFACE TO THE SIXTH EDITION The return from your work must be the satisfaction which that work brings you and the world’s need of that work. With this, life is heaven, or as near heaven as you can get. WILLIAM EDWARD BURGHARDT DU BOIS (1958) For the most part, the stimulus for my continued interest in the field of normal variation comes from the many physicians who have personally communicated their appreciation for the help they have received from this atlas. These comments were offered by a wide spectrum of radiologists, ranging from residents toiling in emergency settings to senior radiologists who have found a variant that has clarified a clinical problem. However, I have concerns that the volume of material that I continue to present may become so large that it may be difficult to contain it in a single volume. Considering the wide range of experience of my audience, it is a difficult decision to eliminate some entries because of their simplicity and others due to their rarity. To alleviate this problem in part I have omitted the section on cholecystography since this technique has virtually disappeared from current clinical practice. Other changes included in this edition are a wide range of new variations that may be troublesome, better examples of previously documented

entities, and the addition of MRI images, which help to explain the nature of some of the variations. In the future, I hope to provide more MRI correlations. I would be remiss in not pointing out that some of the normal skeletal variations presented may be productive of clinical symptoms. These variants represent areas of relative structural weakness and when stressed may become symptomatic. Some of these are described by Dr. Jack Lawson* in a recent publication. I wish to again express my appreciation to the many physicians the world over who have sent me material for inclusion in the book and who have offered suggestions for improvement of the presentation. The warm reception of this work by the readership has been most gratifying in the satisfaction I have gained from this effort and in finding enthusiasm for its continuance. I owe special recognition to my secretary, Patricia West, for years of loyalty and dedication; and to my wife, Patt, for her long interest in and support of my work. Theodore E. Keats *Lawson P: Clinically significant radiologic variants of the skeleton. Am J Roentgenol 163:249, 1994.



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PREFACE TO THE FIFTH EDITION Say not “This is the truth” but “So it seems to me to be as I now see the things I think I see.” Inscription above a doorway at the German Naval Officers School in Kiel, quoted by JOHN MCPHEE in Rising From the Plains The many expressions of acceptance of this work have been most gratifying and have provided me with the stimulus to continue to collect and explain many of the normal phenomena that we see in our everyday work. As I have collected normal roentgen variants over the years, I have heard the repeated criticism that the material is unproven, and in many cases the comment is true. Exploration of findings that are unrelated to symptomatology is not a usual undertaking. The quote above states the situation exactly. The inclusion of what I present is often based largely on the fact that the findings are incidental and asymptomatic, or have been seen repeatedly in other patients in a similar clinical setting. In the first edition, I stated that all entries are subject to further scrutiny and exclusion if necessary. I am delighted to state that over the years only a few have failed to survive the test of time.

In this edition I have included more CT images and some MR examinations to establish the developmental nature of some of the new entries. Unfortunately, not many incidental findings are subjected to these kinds of examinations, and only time will permit further documentation. Mother Nature is inexhaustible in the infinite variety of human development she provides. Since this edition has gone to press, I have collected a great number of new variants for subsequent publications. The task is endless, but it is a labor of love. I would like to express my appreciation to the many physicians who have sent me material and have graciously granted permission to publish these images. I would like to particularly acknowledge the invaluable expertise of Dr. Evan A. Lennon of Sydney, Australia, for his careful proofreading of the manuscript. Thanks are also due to my secretary, Patricia West; my editorial assistant, Carol Chowdhry, Ph.D.; and my wife, Patt, for her encouragement in this work. Theodore E. Keats

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Preface

PREFACE TO THE FOURTH EDITION To study the phenomena of disease without books is to sail an unchartered sea, while to study books without patients is not to go to sea at all. SIR WILLIAM OSLER The publication of this fourth edition reflects the gratifying response of the medical profession to the earlier editions. I have been particularly rewarded by the comments of many radiologists who have indicated that the illustration of these many normal variants has been of great help in their clinical work and in convincing their clinical colleagues of the innocent nature of these findings. I have compiled most of the new entries during the course of my day’s work when I can examine and question patients and try to document the nature of the radiographic findings. Most of the entities in the last edition have stood the test of time. I have removed the illustration of what I believed to be the nutrient foramen of the tibia since I became aware of the typical appearance of the posterior tibial runners’ stress fracture. This

illustration has been replaced with a correct version. I have added a great deal of new material on the cervical spine. I find this portion of the skeleton extremely difficult to interpret and full of pitfalls for the unwary radiologist, not only because of its anatomic structure, but also as a result of faulty positioning and projection. The reader will also find some important new material concerning relationships of joints, particularly in the wrist and the acromioclavicular joint, that violate accepted criteria. I wish to express my appreciation to the many physicians who have permitted me to publish material sent for consultation. I wish to express special appreciation to Dr. Christian Cimmino, of Fredericksburg, Virginia, for his many contributions and his invaluable assistance in unraveling many anatomic riddles. Thanks are also due to my secretary, Patricia West; my editorial assistant, Carol Chowdhry; and my wife, Patt, for making my task easier. Theodore E. Keats



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PREFACE TO THE FIRST EDITION Things are seldom what they seem. Skim milk masquerades as cream. GILBERT & SULLIVAN’s H.M.S. Pinafore The problem of normal variation is a lifelong one for the radiologist, and the mark of his experience is often his ability to recognize a wide range of these entities. Cataloging and describing normal variants demonstrated by roentgenology is of more than academic interest, for recognition of the abnormal first requires full knowledge of the normal. Variation is inseparably related to the study of normal anatomy. In addition, the error of overdiagnosis of a normal variation as evidence of pathology may be more serious than omission and may lead to needless and harmful therapy. When one studies the field of normal variation in detail, he is apt to be overwhelmed by the seemingly infinite variety nature has provided. A detailed study of all of these would be a valuable, but limitless, undertaking. Of more significance are those variations that may simulate disease in the radiograph. It is these variations that form the substance of this initial effort. Those that are shown here represent problems in diagnosis based on my personal experience, on that of my associates as well as on that of successive generations of residents in training. An interest in the subject of normal variations seems to induce spontaneous generation of additional entities so that, at the time of this writing, there appears to be no end in sight, but it is necessary to make a start. It is anticipated that subsequent editions will add additional troublesome variants as well as correct or amplify those herein as new information is obtained. The distinction between a normal anatomic variation and a congenital anomaly is an arbitrary one. I have tried to avoid inclusion of anomalies of development, which are obvious in themselves and often productive of signs and symptoms, but rather have tried to concentrate on those alterations that are essentially incidental findings and significant only in their potential for misinterpretation. The proof of the validity of the material presented is largely subjective, based on personal experience and on the published work of others. It consists largely of having seen the entity many times and of being secure in the knowledge that time has proved the innocence of the lesions. In other cases, follow-up studies indicated that the lesion in question represents a phase of growth that is eliminated by maturation. Still other variants were detected in examination of the side opposite that in question when a radiograph was made for purposes of comparison.

Further experience may prove some of these concepts incorrect; all are, therefore, considered subject to future modification or elimination. This book is arranged in atlas form with the concept that a photographic reproduction of a normal variant is far superior to a text description. The illustrative material, therefore, is emphasized and the text minimal and concise. References are included where the subject is still considered controversial or where documentation is thought necessary. The interested reader is referred to the works Pediatric X-Ray Diagnosis by John Caffey and Dr. Alban Kohler’s Borderlands of the Normal and Early Pathologic in Skeletal Roentgenology. These books represent pioneer efforts in the field of skeletal roentgen variants. This atlas confines itself to roentgen variants seen in conventional roentgenology with no attempt to include those encountered in the specialized fields of angiocardiography, neuroradiology, or the other radiologic specialties. The latter will provide a fruitful source for future study. Included are a number of normal entities that simulate pathology by virtue of growth, or projection, or both. These are not anatomic variations in the true sense, but since they introduce a similar problem, they are included as well. The atlas is arranged by anatomic areas. However, certain specific entities are repeated in more than one section, so the reader searching for a variant may encounter it not only in the anatomic area of its origin, but also in the anatomic section of the lesion it simulates. It is hoped this repetitive arrangement will facilitate recognition, particularly for the less experienced observer. Special acknowledgment is due to Dr. John F. Holt, Professor of Radiology at the University of Michigan, who, as my teacher, first interested me in the subject of normal variation. Throughout his professional career, he has been a student of the subject and has graciously contributed his collection of variants for inclusion in this work. He has also generously contributed time and constructive criticism during the development of this atlas. Without his inspiration and help this work could not have been accomplished. I wish to express my appreciation also to the many unnamed physicians who have contributed to this collection and, in particular, to Drs. Christian Cimmino and Donald Kenneweg of Fredericksburg, Virginia, and Drs. William R. Newman and Clinton L. Rogers of Cumberland, Maryland, for many valuable cases. My thanks, too, to Miss Anne Russell, R.B.P., of the Section of Medical Photography at the University of Virginia, for her invaluable help in the preparation of the illustrations and to my secretary, Miss Ann Rutledge, for her patience and aid in manuscript preparation. Theodore E. Keats

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Contents Foreword  v Preface to the Ninth Edition  vii

The Ethmoid Bone and Ethmoidal Sinuses  76 The Sphenoidal Sinuses  77

Preface to the Eighth Edition  viii

The Zygomatic Arch  78

Preface to the Seventh Edition  ix

The Mandible  78

Preface to the Sixth Edition  x

The Nose  82

Preface to the Fifth Edition  xi Preface to the Fourth Edition  xii Preface to the First Edition  xiii

2 SUPPLEMENT (Online Only)  2S-43 The Orbits  2S-43 The Paranasal Sinuses  2S-46

PART ONE  The Bones  1 1 THE SKULL  3

The Maxillary Sinuses  2S-46 The Frontal Sinuses  2S-49 The Ethmoid Bone and Ethmoidal Sinuses  2S-52 The Sphenoidal Sinuses  2S-53

The Calvaria  3

The Zygomatic Arch  2S-55

Physiologic Intracranial Calcifications  19

The Mandible  2S-56

The Frontal Bone  26

The Nose  2S-60

The Parietal Bone  33 The Occipital Bone  37 The Temporal Bone  52 The Mastoid  54 The Petrous Pyramid  56 The Sphenoid Bone  57 The Base of the Skull  60 The Sella Turcica  64

1 SUPPLEMENT (Online Only)  1S-1 The Calvaria  1S-1 Physiologic Intracranial Calcifications  1S-5 The Frontal Bone  1S-8 The Parietal Bone  1S-13 The Occipital Bone  1S-16 The Temporal Bone  1S-28 The Mastoid  1S-30 The Petrous Pyramid  1S-31 The Sphenoid Bone  1S-34 The Base of the Skull  1S-36 The Sella Turcica  1S-39

2 THE FACIAL BONES  68 The Orbits  68 The Paranasal Sinuses  71 The Maxillary Sinuses  71 The Frontal Sinuses  73

3 THE SPINE  84 The Cervical Spine  84 The Thoracic Spine  189 The Lumbar Spine  204 The Sacrum  238 The Coccyx  250 The Sacroiliac Joints  253

3 SUPPLEMENT (Online Only)  3S-62 The Cervical Spine  3S-62 The Thoracic Spine  3S-98 The Lumbar Spine  3S-104 The Sacrum  3S-116 The Coccyx  3S-121 The Sacroiliac Joints  3S-121

4 THE PELVIC GIRDLE  257 The Ilium  257 The Pubis and Ischium  265 The Acetabulum  275

4 SUPPLEMENT (Online Only)  4S-123 The Ilium  4S-123 The Pubis and Ischium  4S-131 The Acetabulum  4S-134

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Contents

5 THE SHOULDER GIRDLE AND THORACIC CAGE  285 The Scapula  285

The Metacarpals  6S-186 The Sesamoid Bones  6S-187 The Fingers  6S-188

The Clavicle  312 The Sternum  322 The Ribs  335

7 THE LOWER EXTREMITY  485 The Thigh  486 The Femoral Head and Hip Joint  486

5 SUPPLEMENT (Online Only)  5S-139

The Femoral Neck  494

The Scapula  5S-139

The Trochanters  506

The Clavicle  5S-149

The Shaft of the Femur  507

The Sternum  5S-154 The Ribs  5S-155

The Distal End of the Femur  518 The Patella  556 The Leg  580

6 THE UPPER EXTREMITY  354 The Humerus  355 The Proximal Portion of the Humerus  355 The Distal Portion of the Humerus  373 The Forearm  389 The Proximal Portion of the Forearm  389 The Distal Portion of the Forearm  401 The Hand  414 The Carpals  414 The Accessory Ossicles  414 The Carpals in General  422 The Capitate and Lunate Bones  424 The Hamate Bone  432 The Trapezium and Trapezoid Bones  435 The Navicular Bone  437 The Triquetrum Bone  447 The Pisiform Bone  449

The Proximal Ends of the Tibia and Fibula  580 The Shafts of the Tibia and Fibula  607 The Distal Ends of the Tibia and Fibula  617 The Foot  637 The Tarsals  637 The Accessory Ossicles  637 The Talus  653 The Calcaneus  666 The Tarsal Navicular  683 The Cuneiforms  694 The Cuboid  705 The Metatarsals  709 The Sesamoid Bones  740 The Toes  745

7 SUPPLEMENT (Online Only)  7S-191 The Thigh  7S-192

The Metacarpals  454

The Femoral Head and Hip Joint  7S-192

The Sesamoid Bones  467

The Femoral Neck  7S-194

The Fingers  469

The Trochanters  7S-197 The Shaft of the Femur  7S-198

6 SUPPLEMENT (Online Only)  6S-166 The Humerus  6S-167 The Proximal Portion of the Humerus  6S-167 The Distal Portion of the Humerus  6S-170 The Forearm  6S-172 The Proximal Portion of the Forearm  6S-172 The Distal Portion of the Forearm  6S-174 The Hand  6S-178 The Carpals  6S-178 The Accessory Ossicles  6S-178 The Capitate and Lunate Bones  6S-179 The Hamate Bone  6S-180 The Trapezium and Trapezoid Bones  6S-181 The Navicular Bone  6S-182 The Triquetrum Bone  6S-185 The Pisiform Bone  6S-185

The Distal End of the Femur  7S-201 The Patella  7S-211 The Leg  7S-214 The Proximal Ends of the Tibia and Fibula  7S-214 The Shafts of the Tibia and Fibula  7S-218 The Distal Ends of the Tibia and Fibula  7S-219 The Foot  7S-227 The Tarsals  7S-227 The Accessory Ossicles  7S-227 The Talus  7S-230 The Calcaneus  7S-233 The Tarsal Navicular  7S-236 The Cuneiforms  7S-241 The Cuboid  7S-242 The Metatarsals  7S-243 The Sesamoid Bones  7S-249 The Toes  7S-250



Contents

PART TWO The Soft Tissues (Online Only)  761 8 THE SOFT TISSUES OF THE NECK  763 The Soft Tissues of the Neck  763

9 THE SOFT TISSUES OF THE THORAX  792 The Chest Wall  792

11 THE SOFT TISSUES OF THE ABDOMEN  922 The Abdomen in General  923 The Gastrointestinal Tract  943 The Esophagus  943 The Stomach  949 The Duodenum  966 The Small Intestine  973 The Colon  979 The Liver and Biliary Tract  1000

The Pleura  810 The Lungs  824 The Mediastinum  846 The Heart and Great Vessels  871 The Thymus  901

10 THE DIAPHRAGM  914 The Diaphragm  914

12 THE SOFT TISSUES OF THE PELVIS  1006 The Soft Tissues of the Pelvis  1006

13 THE GENITOURINARY TRACT  1016 The Kidneys  1016 The Ureters  1039 The Bladder  1046 The Urethra  1052 The Genital Tract  1055

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PART

ONE The Bones

1

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CHAPTER

1

The Skull PAGES

FIGURES

3 to 18

THE CALVARIA

1–1 to 1–49

19 to 25

PHYSIOLOGIC INTRACRANIAL CALCIFICATIONS

1–50 to 1–71

26 to 32

THE FRONTAL BONE

1–72 to 1–90

33 to 37

THE PARIETAL BONE

1–91 to 1–104

37 to 51

THE OCCIPITAL BONE

1–105 to 1–151

52 to 53 54 to 56 56 to 57

THE TEMPORAL BONE The Mastoid The Petrous Pyramid

1–152 to 1–156 1–157 to 1–164 1–165 to 1–169

57 to 60

THE SPHENOID BONE

1–170 to 1–179

60 to 64

THE BASE OF THE SKULL

1–180 to 1–202

64 to 67

THE SELLA TURCICA

1–203 to 1–216

THE CALVARIA

FIGURE 1-1  Overlapping sutures in a neonate secondary to molding of labor.

3

4

The Skull  |  THE CALVARIA

FIGURE 1-2  Scalp folds in a neonate producing an unusual appearance in the parietal region.

FIGURE 1-3  Scalp fold in the occipital region that could be mistaken for a fracture.

FIGURE 1-4  Hair braids producing an unusual shadow at the vertex of skull.

FIGURE 1-5  Hair braids, with surrounding elastic bands, simulating sclerotic lesions.

FIGURE 1-6  Multiple small hair braids (“cornrows”), producing unusual shadows in the frontal and parietal areas.

The Skull  |  THE CALVARIA

5

PART 1  |  CHAPTER 1



FIGURE 1-7  Two examples of prominent but normal diploic patterns of the calvaria.

A

B

FIGURE 1-8  Localized prominent diploic pattern in the parietal bone (A) produces a striking appearance in Waters’ projection (B).

A

B

FIGURE 1-9  Irregularities and striations in the vertex of the parietal bone caused by the serrations of the sagittal suture. A, Neonate; B, 19-year-old man. (Ref: Sarwar M, et al: Nature of vertex striations on lateral skull radiographs. Radiology 146:90, 1983.)

6

The Skull  |  THE CALVARIA

FIGURE 1-10  Prominent digital markings. The prominence of calvaria digital markings varies widely, particularly between the fourth and tenth years. They do not in themselves necessarily reflect increased intracranial pressure. (Ref: Macaulay D: Digital markings in the radiographs of children. Br J Radiol 288:647, 1951.) It should be noted that infants may occasionally be born without neurologic disease but with lacunar skulls, which resolve spontaneously. (Ref: Taylor B, Barnat HB, Seibert JJ: Neonatal lacunar skull without neurologic disease. South Med J 75:875, 1982.)

FIGURE 1-11  Vascular channels in the parietal bone simulating button sequestra.

FIGURE 1-12  Vascular channels in the frontal bone simulating button sequestra.

FIGURE 1-13  Prominent diploic vascular pattern in a child.

FIGURE 1-14  Unusual calvarial vascular pattern simulating fractures.

The Skull  |  THE CALVARIA

7

PART 1  |  CHAPTER 1



FIGURE 1-15  Two examples of multiple diploic venous lakes, which may simulate metastatic neoplasm. Both patients showed no change on long-term follow-up examinations.

FIGURE 1-16  Two examples of prominent but normal diploic vascular patterns.

FIGURE 1-17  A prominent but normal groove for the sphenoparietal venous sinus.

8

The Skull  |  THE CALVARIA

FIGURE 1-18  Vascular groove (sphenoparietal sinus) simulating fracture.

FIGURE 1-19  Venous vascular groove in the frontal bone, which may be mistaken for fracture.

FIGURE 1-20  Lucent depression of a pacchionian granulation with a large draining vein.

FIGURE 1-21  A rather poorly defined pacchionian depression simulating a destructive lesion, particularly in the lateral projection. (Ref: Branan R, Wilson CB: Arachnoid granulations simulating osteolytic lesions of the calvarium. AJR Am J Roentgenol 127:523, 1976.)

The Skull  |  THE CALVARIA

9

PART 1  |  CHAPTER 1



FIGURE 1-22  Deep but typical pacchionian depressions. The external table of the calvaria is bowed, and the internal table is apparently absent. Failure to appreciate these features may lead to an erroneous diagnosis of erosion of the inner table of the skull.

FIGURE 1-23  Typical pacchionian depression in the frontal bone. In the frontal view, this lucency is often mistaken for a destructive lesion.

FIGURE 1-24  Pacchionian depressions in the occipital bone, an unusual location for this normal entity.

10

The Skull  |  THE CALVARIA

FIGURE 1-25  Anterior fontanel bone.

FIGURE 1-26  Fusing anterior fontanel bone in a 3-year-old boy. This appearance may be confused with that of a depressed fracture in the lateral projection. (Ref: Girdany BR, Blank E: Anterior fontanel bones. Am J Roentgenol Radium Ther Nucl Med 95:148, 1965.)

The Skull  |  THE CALVARIA

11

PART 1  |  CHAPTER 1



FIGURE 1-27  Anterior fontanel bone in a 5-year-old boy. Note its characteristic appearance in Towne’s projection.

FIGURE 1-28  Closing anterior fontanel bone in an 11-year-old boy.

FIGURE 1-29  Remnants of the anterior fontanel bone in a 50-year-old man.

12

The Skull  |  THE CALVARIA

FIGURE 1-30  Wormian (sutural) bones in a 7-year-old child. These may be seen in osteogenesis imperfecta and cleidocranial dysostosis as well.

FIGURE 1-31  Wormian bones in a 19-year-old man.

FIGURE 1-33  Wormian bones at the base of the coronal suture in a newborn (epipteric bones).

FIGURE 1-32  The zygomaticofrontal suture in a neonate.

The Skull  |  THE CALVARIA

13

PART 1  |  CHAPTER 1



FIGURE 1-34  Simulated spread of the coronal sutures in a 4-year-old boy. Sutural prominence is extremely variable, particularly from ages 4 to 8, and should not be mistaken for evidence of increased intracranial pressure. Such early perisutural sclerosis accentuates the prominence of the sutures.

FIGURE 1-35  The posterior portion of the squamosal suture, which may simulate a fracture, particularly in the lateral projection.

FIGURE 1-36  Normal sutural sclerosis of the squamosal suture.

14

The Skull  |  THE CALVARIA

FIGURE 1-37  Normal sutural sclerosis of the coronal suture.

FIGURE 1-38  Thick but normal calvaria in a 30-year-old man.

FIGURE 1-39  Normal frontal, temporal, and occipital lucencies seen in the aging calvaria.

FIGURE 1-40  Striking occipital radiolucency in a 32-year-old woman. These localized normal radiolucencies should not be mistaken for the osteoporosis circumscripta of Paget’s disease.

The Skull  |  THE CALVARIA

15

PART 1  |  CHAPTER 1



FIGURE 1-41  Generalized and frontal benign cranial hyperostosis in a 38-year-old woman.

FIGURE 1-42  Benign cranial hyperostosis in a 65-year-old woman. Diffuse thickening of the calvaria is present, as are localized areas of hyperostosis involving the frontal and parietal bones.

FIGURE 1-43  Frontal and temporal benign cranial hyperostosis in an 81-year-old woman.

16

The Skull  |  THE CALVARIA

FIGURE 1-44  Top left and right, Diffuse intracranial hyperostosis in an 88-year-old woman. The radiolucencies were misinterpreted as metastatic deposits. Bottom right, CT scan shows the radiolucencies caused by intervening clefts between the areas of hyperostosis.

FIGURE 1-45  Localized thickening of the occipital bone, a normal variation.

The Skull  |  THE CALVARIA

17

PART 1  |  CHAPTER 1



FIGURE 1-46  Cranium bifidum occultum. Incomplete closure of the midline of the skull in a 7-year-old boy, not to be mistaken for a destructive process. Such closure defects may be unassociated with bone dysplasia (see Figures 1-73 to 1-74). (Ref: Inoue Y, et al: Cranium bifidum occultum. Neuroradiology 25:217, 1983.)

FIGURE 1-47  Congenital depressions of the calvaria caused by faulty fetal packing. Such depressions manifest at birth and, when not associated with edema or hemorrhage of the overlying soft tissues, are usually due to faulty position in the womb with longstanding pressure from the fetal feet or the maternal sacral promontory. (Refs: Caffey J: Pediatric x-ray diagnosis, ed 8, St. Louis, 1985, Mosby; Eisenberg D, Kirchner SG, Perrin EC: Neonatal skull depressions unassociated with birth trauma. AJR Am J Roentgenol 143:1063, 1984.)

18

The Skull  |  THE CALVARIA

FIGURE 1-48  Slight calvarial depressions in an 18-month-old child, probably representing residua of faulty fetal packing. These depressions usually regress spontaneously without treatment.

FIGURE 1-49  Three examples of “doughnut lesions.” These are not clinically significant and may be seen in any part of the calvaria, including juvenile skulls. They may or may not contain a central area of sclerosis. (Ref: Keats TE, Holt JF: The calvarial “doughnut lesion”: A previously undescribed entity. Am J Roentgenol Radium Ther Nucl Med 105:314, 1969.)

The Skull  |  PHYSIOLOGIC INTRACRANIAL CALCIFICATIONS

PHYSIOLOGIC INTRACRANIAL CALCIFICATIONS

FIGURE 1-50  The habenular commissure (m) and the pineal gland (m 6 ).

FIGURE 1-51  Large cystic pineal gland in a 60-year-old man. This finding in itself is of no clinical significance.

FIGURE 1-52  Petroclinoid ligament with heavy calcification. FIGURE 1-53  Petroclinoid ligament with irregular calcification.

19

PART 1  |  CHAPTER 1



20

The Skull  |  PHYSIOLOGIC INTRACRANIAL CALCIFICATIONS

FIGURE 1-54  Two examples of calcification between the middle and posterior clinoid processes.

FIGURE 1-55  The os supra petrosum of Meckel, a physiologic calcification under, or adherent to, the dura on the anteroposterior surface of the petrous bone, near its tip. Note its position in the lateral projection, superimposed on the sella turcica, which permits its differentiation from petroclinoid ligament calcification. (Refs: Currarino G, Weinberg A: Os supra petrosum of Meckel. Am J Roentgenol Radium Ther Nucl Med 121:139, 1974; Keats TE: The os supra petrosum of Meckel and nodular petroclinoid ligament calcification. Va Med 104:114, 1977.)

FIGURE 1-56  Prominent frontal crest on the internal surface of the frontal bone, simulating calcification of the falx cerebri in a healthy 4-year-old boy.

The Skull  |  PHYSIOLOGIC INTRACRANIAL CALCIFICATIONS

21

PART 1  |  CHAPTER 1



FIGURE 1-57  Localized focal dural calcification in the parietal area.

FIGURE 1-58  Localized focal dural calcification in the frontal area.

FIGURE 1-59  Multiple focal areas of dural calcification in a 71-year-old man.

22

The Skull  |  PHYSIOLOGIC INTRACRANIAL CALCIFICATIONS

FIGURE 1-60  Calcification of the falx cerebri.

FIGURE 1-61  Heavy calcification in the falx cerebri in the frontal and lateral projections.

FIGURE 1-62  Three types of physiologic calcification. Demonstrated are petroclinoid ligament (m), heavy calcification of the tentorium cerebelli (m 6), and falx cerebri (m 66).

The Skull  |  PHYSIOLOGIC INTRACRANIAL CALCIFICATIONS

23

PART 1  |  CHAPTER 1



FIGURE 1-63  Minor calcification of the tentorium cerebelli (m). Calcification is also present in the falx (m 6 ) and the pineal gland (m 66). (Ref: Saldino RM, Di Chiro G: Tentorial calcification. Radiology 111:207, 1974.)

FIGURE 1-64  Calcification in the glomus of the choroid plexus of each lateral ventricle.

FIGURE 1-65  Calcification in the glomus of the choroid plexus (boomerang configuration).

The Skull  |  PHYSIOLOGIC INTRACRANIAL CALCIFICATIONS

24

FIGURE 1-66  Calcification of the internal carotid arteries.

FIGURE 1-67  Calcification of the internal carotid arteries with very dense calcification in the lateral projection.

A

B

FIGURE 1-68  Pituitary stones seen in lateral (A) and basal (B) projections in a 46-year-old man. Such stones may be seen in asymptomatic patients and in patients with hypopituitarism. (Ref: Taylor HC, et al: Pituitary stones and associated hypopituitarism. JAMA 242:751, 1979.)

The Skull  |  PHYSIOLOGIC INTRACRANIAL CALCIFICATIONS

25

PART 1  |  CHAPTER 1



FIGURE 1-69  Large pituitary stone in a 20-year-old woman.

FIGURE 1-70  Calcification in the dentate nucleus of the cerebellum. This form of calcification is not necessarily of clinical significance and may be physiologic.

FIGURE 1-71  Idiopathic calcification of the basal ganglia may be familial and unassociated with other disease.

26

The Skull  |  THE FRONTAL BONE

THE FRONTAL BONE

FIGURE 1-72  Persistent metopic suture showing unusual serrations. The straight line is in the inner table, the serrated in the outer.

FIGURE 1-73  Cranium bifidum occultum in a 9-month-old girl.

FIGURE 1-74  Cranium bifidum occultum in a 28-year-old woman.

The Skull  |  THE FRONTAL BONE

27

PART 1  |  CHAPTER 1



FIGURE 1-75  Top, Asymptomatic palpable developmental fossa in the frontal bone in an 8-month-old child. Bottom, In the same child at 5 years of age, the fossa is still present, essentially unchanged.

FIGURE 1-76  Midline frontal accessory bone in an 11-month-old boy.

28

The Skull  |  THE FRONTAL BONE

FIGURE 1-77  Prominent nasofrontal suture, not to be mistaken for a fracture. This suture may persist into adult life.

FIGURE 1-78  Sclerosis of the nasofrontal suture, which might be mistaken for a meningioma of the anterior fossa.

FIGURE 1-79  The nasofrontal suture in lateral projection.

FIGURE 1-80  The nasofrontal suture in a 13-year-old girl.

The Skull  |  THE FRONTAL BONE

29

PART 1  |  CHAPTER 1



FIGURE 1-81  Top and bottom, Two examples of prominent frontal crests in children simulating calcification of the falx.

FIGURE 1-82  Vascular channels above the frontal sinuses.

30

The Skull  |  THE FRONTAL BONE

FIGURE 1-83  Three additional examples of frontal bone vascular grooves, which might be mistaken for fractures.

FIGURE 1-84  Vascular groove in the frontal bone mistaken for a fracture. Left, Plain film. Right, CT scan.

The Skull  |  THE FRONTAL BONE

31

PART 1  |  CHAPTER 1



FIGURE 1-86  Diffuse benign hyperostosis of the frontal bone. FIGURE 1-85  Nodular benign hyperostosis frontalis interna.

FIGURE 1-87  Asymmetric unilateral hyperostosis frontalis interna in a 28-year-old woman.

A

B FIGURE 1-88  A, B. Early asymmetric hyperostosis frontalis interna in a 35-year-old man. This entity is much less common in males.

32

The Skull  |  THE FRONTAL BONE

FIGURE 1-89  Hyperostosis frontalis interna with a simulated doughnut lesion.

FIGURE 1-90  Localized frontal calvarial osteoporotic thinning in an 84-year-old woman.

The Skull  |  THE PARIETAL BONE

33

THE PARIETAL BONE

FIGURE 1-91  Plain films of two neonates showing parietal fissures caused by persistent strips of membranous bone matrix. These fissures, which disappear as the child matures, are often mistaken for fractures.

FIGURE 1-92  Unilateral intraparietal suture, which divides the parietal bone into upper and lower segments. This suture, which may also occur bilaterally, extends from the coronal suture to the lambdoid suture. (Ref: Shapiro R: Anomalous parietal sutures and the bipartite parietal bone. Am J Roentgenol Radium Ther Nucl Med 115:569, 1972.)

FIGURE 1-93  Unilateral intraparietal suture. When this suture is unilateral, the skull may be asymmetric and the side harboring the intraparietal suture may be larger than the opposite side, as is the case here.

PART 1  |  CHAPTER 1



34

The Skull  |  THE PARIETAL BONE

FIGURE 1-94  Bilateral subsagittal sutures in a 1-year-old child.

FIGURE 1-95  Unusual lucencies in the parietal bones crossing the midline, apparently representing a sagittal intrasutural bone, an incidental finding in an adult woman.

FIGURE 1-96  Normal parietal foramina, which transmit the emissary veins of Santorini.

The Skull  |  THE PARIETAL BONE

35

PART 1  |  CHAPTER 1



FIGURE 1-97  Parietal foramina. These congenital defects vary in size but are consistent in location and are often symmetric. They are not significant except in the differential diagnosis of cranial defects, including burr holes.

FIGURE 1-98  Paired parietal foramina, an unusual variant.

FIGURE 1-99  Parietal foramina without a central dividing strip in a 15-month-old child.

36

The Skull  |  THE PARIETAL BONE

FIGURE 1-101  Unusual venous vascular markings in parietal bone. This area frequently shows a striking vascular pattern. FIGURE 1-100  Parietal foramina demonstrated by three-dimensional CT.

FIGURE 1-102  Parietal thinning, a manifestation of postmenopausal osteoporosis. The outer table is lost, with characteristic preservation of the inner table. Also note similar localized thinning of the frontal bone in the lateral projection. (Ref: Steinbach HL, Obata WG: The significance of thinning of the parietal bones. Am J Roentgenol Radium Ther Nucl Med 78:39, 1957.) Parietal thinning is rarely unilateral. (Ref: Wilson AK: Thinness of parietal bones. Am J Roentgenol Radium Ther Nucl Med 58:724, 1947.)

FIGURE 1-103  Combined parietal thinning and venous lakes and grooves in a 56-year-old woman.

The Skull  |  THE OCCIPITAL BONE

37

PART 1  |  CHAPTER 1



FIGURE 1-104  Parietal thinning in an 82-year-old man. This entity is much less common in males.

THE OCCIPITAL BONE

FIGURE 1-105  Unusual occipital configuration in the newborn is due to the molding of labor.

FIGURE 1-106  Occipital and parietal fissures (n) caused by persistent strips of membranous bone, a common finding in infants that may simulate fracture. The mendosal sutures are evident (6n).

FIGURE 1-107  The mendosal suture (n) and synchondrosis between the supraoccipital and exoccipital portions of the occipital bone (6n) in lateral projection in a 1-year-old child.

38

The Skull  |  THE OCCIPITAL BONE

FIGURE 1-109  Appearance of the accessory supraoccipital ossicle in the lateral projection.

FIGURE 1-108  Accessory ossicle of the supraoccipital bone (Kerckring’s ossicle) in a normal infant. (Ref: Caffey J: On accessory ossicles of supraoccipital bone: some newly recognized roentgen features of normal infantile skull. Am J Roentgenol Radium Ther Nucl Med 70:401, 1953.)

FIGURE 1-111  Irregular midline occipital ossicle in a 6-month-old girl.

FIGURE 1-110  Unilateral ossicle of the supraoccipital bone.

The Skull  |  THE OCCIPITAL BONE

39

PART 1  |  CHAPTER 1



FIGURE 1-112  Bathrocephaly in a 1-year-old child.

FIGURE 1-113  Bathrocephaly in an adult, which may be confused with a fracture.

FIGURE 1-114  Bathrocephalic occiputs in adults.

FIGURE 1-115  Normal large interparietal bone in a 3-month-old child in the frontal and lateral projections.

40

The Skull  |  THE OCCIPITAL BONE

FIGURE 1-116  Three examples of bifid interparietal bones (Inca bone). This finding should not be mistaken for a fracture. (Ref: Shapiro R, Robinson F: The os incae. AJR Am J Roentgenol 127:469, 1976.)

FIGURE 1-117  M-shaped Inca bone and occipital molding (breech head). This abnormal head shape is identified as a positive deformation associated with breech intrauterine position. It resolves during infancy with no residual impairment in most cases. (Ref: Haberkern CM, Smith DW, Jones KL: The “breech head” and its relevance. Am J Dis Child 133:154, 1979.)

The Skull  |  THE OCCIPITAL BONE

41

PART 1  |  CHAPTER 1



FIGURE 1-118  Cone-shaped interparietal bone.

FIGURE 1-120  Anterior fontanel bone seen in the occipital projection in a 14-year-old.

FIGURE 1-119  Paired, laterally placed interparietal bones.

FIGURE 1-121  Occipital flattening caused by postural pressure, not to be confused with changes of craniosynostosis.

FIGURE 1-122  The superior median fissure of the occipital bone in a 21-year-old patient (m); this should not be mistaken for a fracture. Also note persistence of a strip of membranous bone simulating a fracture (m 6 ).

42

The Skull  |  THE OCCIPITAL BONE

FIGURE 1-123  Persistent mendosal sutures in a 17-year-old boy.

A

B

C

FIGURE 1-124  Persistent mendosal sutures in a 25-year-old man. A, Open-mouth odontoid view. B, Lateral projection. C, CT scan.

The Skull  |  THE OCCIPITAL BONE

43

PART 1  |  CHAPTER 1



A

B

FIGURE 1-125  Unilateral persistent mendosal suture in a 46-year-old man. A, Frontal projection. B, Occipital projection. C, Lateral projection.

C

FIGURE 1-126  Anomalous midline occipital suture (cerebellar synchondrosis). This is also a common site of fractures in small children, so the diagnosis of an anomalous suture should be made with caution. Left, Adult with sutural sclerosis evident. Right, Child with no history of trauma. (Ref: Franken EA Jr: The midline occipital fissure: Diagnosis of fracture versus anatomic variant. Radiology 93:1043, 1969.)

44

The Skull  |  THE OCCIPITAL BONE

FIGURE 1-127  Two examples of asymmetric prominence of one occipitomastoid suture suggesting fracture.

FIGURE 1-128  Sutural bone in the occipitomastoid suture.

FIGURE 1-129  Defects in the lambdoid suture, presumably representing persistent mastoid fontanels. The patient did not have neurofibromatosis.

FIGURE 1-130  A portion of the sagittal suture seen through the occipital bone, simulating a fracture.

The Skull  |  THE OCCIPITAL BONE

45

PART 1  |  CHAPTER 1



FIGURE 1-131  Two examples of the foramen for the occipital emissary vein. This is a midline structure, in contrast to the venous lakes, which are seen on both sides of the midline. (Ref: O’Rahilly R: Anomalous occipital apertures. AMA Arch Pathol 53:509, 1952.)

FIGURE 1-132  Occipital pacchionian impression.

FIGURE 1-133  Left, Occipital pacchionian impression (m). Note the draining vein (m 6). Right, Confirmation on CT scan. (Ref: Skully RD, Mark EJ, McNeely BV: Case 42-1984: Pacchionian granulation. N Engl J Med 322:1036, 1984.)

46

The Skull  |  THE OCCIPITAL BONE

FIGURE 1-134  Occipital venous lakes. These structures vary widely in number and appearance. They are usually seen near the midline of the occipital bone, most commonly in older individuals. These lakes lie in the diploic space and are of no clinical significance. (From Keats TE: Four normal anatomic variations of importance to radiologists. Am J Roentgenol Radium Ther Nucl Med 78:89, 1957.) There is evidence that identical occipital radiolucencies may be the product of ectopic neural tissue. These are without clinical significance. (Ref: Goldring S, et al: Ectopic neural tissue of the occipital bone J Neurosur 21:479, 1964.)

FIGURE 1-135  Venous lakes may often be seen in the diploic space in the lateral projection.

The Skull  |  THE OCCIPITAL BONE

47

PART 1  |  CHAPTER 1



FIGURE 1-136  Similar occipital radiolucencies with demonstration on CT scan.

FIGURE 1-137  Normal unilateral prominence of the groove for the transverse venous sinus.

48

The Skull  |  THE OCCIPITAL BONE

FIGURE 1-138  The transverse sinuses seen on end, evidenced as lucencies in the mastoids.

FIGURE 1-139  Localized thickening of the occipital bone, a normal variant.

FIGURE 1-140  Striking appearance of the occipital region produced by venous sinuses and normal lucency of the occipital bones.

FIGURE 1-141  Pneumatization of the occipital bone as an extension from the mastoids.

The Skull  |  THE OCCIPITAL BONE

49

PART 1  |  CHAPTER 1



A

B

FIGURE 1-142  Developmental thinning of the occipital bone (A) proved by CT scan. The defect contains normal brain tissue (B). (From Haden MA, Keats TE: The anatomic basis for localized occipital thinning: A normal anatomic variant. Skeletal Radiol 8:221, 1982.)

FIGURE 1-143  Additional examples of occipital thinning. Note similarity to changes of erosion of inner table.

FIGURE 1-144  Asymmetric occipital thinning below the torcular herophili in a 28-year-old woman.

50

The Skull  |  THE OCCIPITAL BONE

FIGURE 1-145  Symmetric areas of occipital thinning simulating a pneumoencephalogram.

FIGURE 1-146  Occipital thinning seen in lateral projection above the transverse sinuses. Note the apparent loss of the inner table of the calvaria.

FIGURE 1-147  Prominent external occipital protuberance producing a midline density in the half-axial projection.

FIGURE 1-148  Prominent external occipital protuberance with adjacent calcification in the ligamentum nuchae.

FIGURE 1-149  Radiolucency produced by the base of the external occipital protuberance.

The Skull  |  THE OCCIPITAL BONE

51

PART 1  |  CHAPTER 1



A

B

C FIGURE 1-150  Paracondylar process. This cone-shaped, bony structure projects down from the lateral aspect of the occipital condyle toward the transverse process of C1. It may be unilateral or bilateral. A, Lateral projection. B, C, Tomograms. (Ref: Shapiro R, Robinson F: Anomalies of the craniovertebral border. AJR Am J Roentgenol 127:281, 1976.)

FIGURE 1-151  Squamoparietal suture in an 8-month-old should not be mistaken for a fracture (see Fig. 1-35).

52

The Skull  |  THE TEMPORAL BONE

THE TEMPORAL BONE

FIGURE 1-152  Two examples of grooves for the middle temporal artery simulating fractures. (Ref: Schunk H, Maruyama Y: Two vascular grooves of the external table of the skull that simulate fractures. Acta Radiol 54:186, 1960.)

FIGURE 1-153  Two examples of vascular grooves in the temporal bone simulating fractures. (Ref: Allen WE, 3rd, et al: Pitfalls in the evaluation of skull trauma: A review. Radiol Clin North Am 11:479, 1973.)

FIGURE 1-154  Additional examples of vascular grooves that may be mistaken for fractures.

The Skull  |  THE TEMPORAL BONE

53

PART 1  |  CHAPTER 1



FIGURE 1-155  Exaggeration of the normal lucency of the squamosal portion of the temporal bone.

FIGURE 1-156  Isolated hyperostosis interna of the temporal bones.

54

The Skull  |  THE TEMPORAL BONE

The Mastoid

FIGURE 1-157  Large antrum simulating a destructive lesion.

FIGURE 1-158  Air in the external auditory canal, seen as discrete radiolucency.

FIGURE 1-159  Large mastoid antra, which might be mistaken for cholesteatomas. (Ref: Tillitt R, et al: The large mastoid antrum. Radiology 94:619, 1970.)

The Skull  |  THE TEMPORAL BONE

55

PART 1  |  CHAPTER 1



A

B

FIGURE 1-160  A, An example of unusually marked pneumatization of the mastoids. B, A detailed view of the mastoid air cells.

FIGURE 1-161  Extremely marked pneumatization of the mastoid.

FIGURE 1-162  Large asymmetric mastoid air cell, which might be mistaken for an area of bone destruction.

56

The Skull  |  THE TEMPORAL BONE

FIGURE 1-163  Large mastoid emissary vein.

FIGURE 1-164  Sigmoid sinus (m) and mastoid emissary vein (m 66).

The Petrous Pyramid

FIGURE 1-165  Normal asymmetry in height of the petrous ridges. This entity may occasionally be associated with trigeminal neuralgia. (Ref: Obrador S, et al: Trigeminal neuralgia secondary to asymmetry of the petrous bone: Case report. J Neurosurg 33:596, 1970.)

FIGURE 1-166  Large mastoid air cells at the petrous tips simulating the changes of acoustic neuroma. (Ref: Dubois PJ, Roub LW: Giant air cell of petrous apex: Tomographic feature. Radiology 129:103, 1978.)

FIGURE 1-167  Pneumatization of one petrous tip simulating enlargement of the internal auditory meatus.

FIGURE 1-168  Apparent destruction of the petrous tips caused by pneumatization.

The Skull  |  THE SPHENOID BONE

57

PART 1  |  CHAPTER 1



FIGURE 1-169  The os supra petrosum of Meckel (see Fig. 1-55).

THE SPHENOID BONE

FIGURE 1-170  Normal asymmetry of the lesser wings of the sphenoid. Note the arching of the wing on the right.

FIGURE 1-171  Asymmetry of the lesser wings of the sphenoid in a normal individual simulating bone destruction of the left (m). Note also the normal asymmetry of the superior orbital fissures (m 66). (Ref: Shapiro R, Robinson F: Alterations of the sphenoidal fissure produced by local and systemic processes. Am J Roentgenol Radium Ther Nucl Med 101:814, 1967.)

58

The Skull  |  THE SPHENOID BONE

FIGURE 1-172  Asymmetry of the lesser wings of the sphenoid (m) and superior orbital fissures (m 66).

FIGURE 1-173  Four additional examples of normal variation and asymmetry of the lesser wings of the sphenoid.

FIGURE 1-174  Developmental spurs from the lesser wings of the sphenoid.

The Skull  |  THE SPHENOID BONE

59

PART 1  |  CHAPTER 1



FIGURE 1-175  Asymmetric pneumatization of the anterior clinoid processes simulating abnormality of the optic canals.

FIGURE 1-176  Lateral extension of sphenoidal sinus air cell into the greater wing of the sphenoid simulating a destructive lesion.

FIGURE 1-177  Lateral strut of the lesser wings of the sphenoid simulating changes of a meningioma.

FIGURE 1-178  Two examples of the pterion, which may simulate a meningioma of the planum sphenoidale.

60

The Skull  |  THE Base of the skull

FIGURE 1-179  Nonunited ossification center of the presphenoid bone, which might be mistaken for evidence of a meningioma. Left, Separate wellcorticated ossicle (arrow) posterior and superior to the anterior clinoid. Right, Lateral tomogram showing separate center at the anterior clinoid process. The anterior clinoids are superior, and the inferior clinoids are inferior. (From Ratner LM, Quencer RM: AJR Am J Roentgenol 143:503, 1983.)

THE BASE OF THE SKULL

FIGURE 1-180  Coronal suture, seen in the base view, simulating a fracture.

FIGURE 1-181  The sagittal suture, seen in the base view, simulating a fracture.

FIGURE 1-182  Synchondrosis between the basisphenoid and basiocciput in a 2-year-old boy. This suture normally closes near puberty but may persist until 20 years of age. It is at times mistaken for a fracture.

FIGURE 1-183  Basisphenoid-basiocciput synchondrosis in a 5-year-old girl, shown on tomogram.

The Skull  |  THE Base of the skull

61

PART 1  |  CHAPTER 1



FIGURE 1-184  Sphenofrontal suture (n) and the sphenotemporal sutures (6n 6 ) in an 18-month-old child. Note also the basisphenoid basiocciput synchondrosis (6n). 66

FIGURE 1-185  Unfused planum sphenoidale (m), simulating a fracture. This is a developmental variation. In fractures, the anterior fragment of the planum is depressed, compared with this variation, in which the planum is superior to the chiasmatic sulcus (m 66). (Ref: Smith TR, Kier EL: The unfused planum sphenoidale: differentiation from fracture. Radiology 98:305, 1971.)

FIGURE 1-186  Normal planum sphenoidale for comparison with Figure 1-185.

FIGURE 1-187  Normal asymmetry of the basal foramina. (Ref: Shapiro R, Robinson F: The foramina of the middle fossa: a phylogenetic, anatomic and pathologic study. Am J Roentgenol Radium Ther Nucl Med 101:779, 1967.)

FIGURE 1-188  An example of striking asymmetry of the basal foramina. The foramen ovale (n) and the foramen spinosum (6n) 6 are confluent on the patient’s right side, simulating destruction of the base of the skull. (Ref: Newton TH, Potts DG: Radiology of the skull and brain, vol 1, St. Louis, 1971, Mosby.)

FIGURE 1-189  Marked asymmetric development of the foramina ovale.

62

The Skull  |  THE Base of the skull

FIGURE 1-190  Very large jugular foramina with striking prominence on the right (m). Note the unusual shadow in the nasopharynx caused by the epiglottis (m 66).

FIGURE 1-191  Junction of the frontal and ethmoid bones in a 3-monthold child might be mistaken for a fracture.

FIGURE 1-192  Large sphenoidal air cell simulating an enlarged basal foramen.

FIGURE 1-193  Pneumatization of the pterygoid bones producing unusual radiolucency in the base of the skull.

FIGURE 1-194  Left, Normal asymmetry of foramina rotunda seen in Caldwell’s projection. Right, Asymmetry of the infraorbital foramina seen in Waters’ projection.

The Skull  |  THE Base of the skull

63

PART 1  |  CHAPTER 1



FIGURE 1-195  Pneumatization of the clinoid processes may produce spurious foramen-like shadows in the base view.

FIGURE 1-196  Nasolacrimal canals.

FIGURE 1-197  Uvula seen in the nasopharyngeal air shadow.

FIGURE 1-198  Unfused anterior arch of C1 vertebra in a base view of the skull.

FIGURE 1-199  Shadow of the folded ear simulating suprasellar calcification.

64

The Skull  |  THE SELLA TURCICA

FIGURE 1-200  Intersphenoidal synchondrosis in a newborn. This entity should not be mistaken for a fracture, a persistent basipharyngeal canal, or the sphenooccipital synchondrosis. It has no pathologic significance and usually disappears by 3 years of age. (Ref: Shopfner CE, et al: The intersphenoid synchondrosis. Am J Roentgenol Radium Ther Nucl Med 104:184, 1968.)

FIGURE 1-201  Partially obliterated intersphenoidal synchondrosis in a 2-year-old child.

FIGURE 1-202  Obliterated intersphenoidal synchondrosis in an adult.

THE SELLA TURCICA

FIGURE 1-203  Large normal tuberculum sella turcica (n).

FIGURE 1-204  Well-defined middle clinoid process.

The Skull  |  THE SELLA TURCICA

65

PART 1  |  CHAPTER 1



FIGURE 1-205  Additional examples of prominent middle clinoid processes.

FIGURE 1-206  Bridging of the sella turcica caused by calcification of the interclinoid ligaments.

FIGURE 1-207  Heavy bridging of the sella turcica.

FIGURE 1-208  Ligamentous calcification between the posterior and middle clinoid processes.

FIGURE 1-209  Bridging between the anterior and middle clinoid processes.

66

The Skull  |  THE SELLA TURCICA

FIGURE 1-210  Very large clinoid processes, producing apparent bridging of the sella.

A

FIGURE 1-211  Pneumatization of the planum sphenoidale producing an unusual appearance.

B

FIGURE 1-212  A, B, Apparent cleft in the posterior clinoids secondary to lateral extensions of the dorsum sellae (arrows in B).

FIGURE 1-213  Unusual appearance of the dorsum sellae caused by heavy calcification of the petroclinoid ligament.

The Skull  |  THE SELLA TURCICA

67

PART 1  |  CHAPTER 1



A

B

FIGURE 1-214  Normal variations in the shape of the sella turcica. A, The small sella. B, The shallow sella.

FIGURE 1-215  Double floor of the sella turcica as a result of inclination of the sella. (Ref: Tenner MS, Weitzner I Jr: Pitfalls in the diagnosis of erosive changes in the expanding lesions of the pituitary fossa. Radiology 137:393, 1980.)

A

B

FIGURE 1-216  Normal variations of the sella turcica. A, Hidden anterior clinoid processes caused by pneumatization. B, Extensive pneumatization of the clinoid processes and dorsum sellae.

CHAPTER

1

The Skull

FIGURES

THE CALVARIA

1S-1 to 1S-16

PHYSIOLOGIC INTRACRANIAL CALCIFICATIONS

1S-17 to 1S-24

THE FRONTAL BONE

1S-25 to 1S-39

THE PARIETAL BONE

1S-40 to 1S-46

THE OCCIPITAL BONE

1S-47 to 1S-84

THE TEMPORAL BONE The Mastoid The Petrous Pyramid

1S-85 to 1S-90 1S-91 to 1S-94 1S-95 to 1S-104

THE SPHENOID BONE

1S-105 to 1S-109

THE BASE OF THE SKULL

1S-110 to 1S-121

THE SELLA TURCICA

1S-122 to 1S-132

THE CALVARIA

FIGURE 1S-1  The relative proportions of the cranial vault size to face size in the infant differ strikingly from those in the adult. Applying adult standards to the infant may suggest a disproportionate increase in vault size. At birth, the head-to-face ratio is approximately 4:1; in adulthood, this ratio is 3:2. (Ref: Watson EH, Lowrey GH: Growth and Development of Children, 5th ed. St. Louis, Mosby, 1967.) (From Keats TE: Pediatric radiology: Some potentially misleading variations from the adult. Va Med 96:630, 1966.)

1S-1

1S-2

The Skull  |  THE CALVARIA

FIGURE 1S-2  Occipital skin folds.

FIGURE 1S-3  Striations over the parietal area caused by hair.

FIGURE 1S-4  Hair arrangements—in these two cases a ponytail may produce unusual shadows.

FIGURE 1S-5  Prominent venous vascular groove at the vertex of the skull.

FIGURE 1S-6  Vascular groove (sphenoparietal sinus) simulating fracture.



The Skull  |  THE CALVARIA

1S-3

FIGURE 1S-7  Pacchionian depression with a central area of density. This appearance is often mistaken for a significant lesion such as an eosinophilic granuloma. (Ref: Branan R, Wilson CB: Arachnoid granulations simulating osteolytic lesions of the calvarium. AJR Am J Roentgenol 127:523, 1976.)

FIGURE 1S-8  Large pacchionian granulations of the vertex of the skull that lend an unusual configuration to the vertex.

FIGURE 1S-10  Wormian bones in a 9-year-old boy.

FIGURE 1S-9  Huge anterior fontanel bone in a 1-year-old child.

1S-4

The Skull  |  THE CALVARIA

FIGURE 1S-11  Normal squamosal suture projected tangentially, simulating a fracture.

FIGURE 1S-12  Tangential projection of the squamosal suture producing a less obvious simulated fracture.

FIGURE 1S-13  Early sutural sclerosis in a 12-year-old boy.

FIGURE 1S-14  Localized thickening of the parietal bone, a normal variation.

FIGURE 1S-15  Parieto-occipital hyperostosis.



The Skull  |  PHYSIOLOGIC INTRACRANIAL CALCIFICATIONS

1S-5

FIGURE 1S-16  Localized palpable thinning of the outer table of the skull in an asymptomatic 21-year-old woman. This probably represents an incomplete form of cranium bifidum occultum.

PHYSIOLOGIC INTRACRANIAL CALCIFICATIONS

FIGURE 1S-17  Petroclinoid calcification in the half-axial projection.

FIGURE 1S-18  Petroclinoid ligament with an unusual pattern of calcification.

1S-6

The Skull  |  PHYSIOLOGIC INTRACRANIAL CALCIFICATIONS

FIGURE 1S-20  The os supra petrosum of Meckel, seen on polytomography. FIGURE 1S-19  Unusual dural calcifications above anterior and posterior clinoid processes.

FIGURE 1S-21  Small localized focal dural calcification in the frontal area.

FIGURE 1S-22  Heavy calcification of the falx cerebri.



The Skull  |  PHYSIOLOGIC INTRACRANIAL CALCIFICATIONS

1S-7

FIGURE 1S-23  Normal asymmetry of the calcified glomera of the choroid plexus. These cannot be reliably used for evidence of intracranial abnormality.

FIGURE 1S-24  Unilateral calcification of the glomus of the choroid plexus.

1S-8

The Skull  |  THE FRONTAL BONE

THE FRONTAL BONE

FIGURE 1S-25  Closing metopic suture mistaken for a fracture in a 11⁄ 2-year-old boy. Closure occurs last in the cephalic end of the suture.

FIGURE 1S-26  Persistent metopic suture in a young adult. This suture may persist throughout life and may be mistaken for a fracture.

FIGURE 1S-27  Groove for the sagittal suture projected through the frontal bone, simulating a metopic suture.



The Skull  |  THE FRONTAL BONE

FIGURE 1S-28  Unfused areas in the midline of the frontal bone (cranium bifidum occultum) in a 15-year-old child.

FIGURE 1S-29  Cranium bifidum occultum in a 14-month-old boy.

1S-9

1S-10 The Skull  |  THE FRONTAL BONE

FIGURE 1S-30  Large external occipital protuberance projected through the frontal bone, simulating meningioma of the anterior fossa.

FIGURE 1S-31  Unusual scalloped appearance of the floor of the anterior fossa.

FIGURE 1S-32  Vascular channel simulating a skull fracture. (Ref: Schunk H, Maruyama Y: Two vascular grooves of the external table of the skull which simulate fractures. Acta Radiol 54:186, 1960.)



The Skull  |  THE FRONTAL BONE

FIGURE 1S-33  Unilateral serpentine vascular channels in the frontal bone.

FIGURE 1S-34  Vascular groove simulating a fracture in a 1-year-old boy.

FIGURE 1S-35  Vascular channel of the frontal bone, unusually well seen in lateral projection. (Courtesy Dr. Wa’el M.A. Al-Bassam.)

1S-11

1S-12 The Skull  |  THE FRONTAL BONE

FIGURE 1S-37  Nebular hyperostosis frontalis interna. FIGURE 1S-36  Focal thickening of the inner table of the frontal bone.

FIGURE 1S-38  Asymmetric localized hyperostosis frontalis interna in a 20-year-old woman.

FIGURE 1S-39  Hyperostosis frontalis interna with a simulated sequestrum.



The Skull  |  THE PARIETAL BONE

THE PARIETAL BONE

FIGURE 1S-40  Persistence of parietal fissure in a 1-year-old child, simulating a fracture.

FIGURE 1S-41  Parietal emissary vascular channel. Note the depression in the outer table at its point of exit.

FIGURE 1S-42  Parietal foramina showing some asymmetry.

1S-13

1S-14 The Skull  |  THE PARIETAL BONE

FIGURE 1S-43  Asymmetric and irregular parietal foramina.

FIGURE 1S-44  Unusual parietal foramina.



The Skull  |  THE PARIETAL BONE

1S-15

FIGURE 1S-45  Localized area of thinning of the external table at the site of the anterior fontanel. This should not be mistaken for erosion of the outer table.

FIGURE 1S-46  Hyperostosis corticalis generalisata and hyperostosis parietalis.

1S-16 The Skull  |  THE OCCIPITAL BONE

THE OCCIPITAL BONE

FIGURE 1S-48  Fissures in an infant around foramen magnum.

FIGURE 1S-47  Apparent malalignment of the parietal and occipital bones caused by molding of labor, not to be mistaken for fracture (n). A cephalohematoma is present (6 n).

FIGURE 1S-50  The synchondroses between the supraoccipital and exoccipital portions of the occipital bone in a 6-week-old child (n). The mendosal sutures are also seen (n). FIGURE 1S-49  Persistent membranous fissures simulating a fracture in an adolescent girl.

FIGURE 1S-51  Occipital ossicle in the lateral projection.



The Skull  |  THE OCCIPITAL BONE

1S-17

FIGURE 1S-52  Bathrocephalic occiputs in adults.

FIGURE 1S-53  Two examples of how Inca bones may simulate fractures in the lateral projection.

FIGURE 1S-54  Rectangular interparietal bone in an adult.

FIGURE 1S-55  Small interparietal bone that has persisted into adult life.

1S-18 The Skull  |  THE OCCIPITAL BONE

FIGURE 1S-56  Examples of asymmetric closure of the synchondrosis between the supraoccipital and exoccipital portions of the occipital bone. Left, A 15-month-old infant. Right, A 12-month-old infant. The open suture may be mistaken for a fracture.

FIGURE 1S-57  Visualization of the inner and outer aspects of the lambdoidal suture, suggesting diastatic fracture.



The Skull  |  THE OCCIPITAL BONE

FIGURE 1S-58  Mendosal suture in a 29-month-old child, mistaken for a fracture.

FIGURE 1S-59  PA and AP projections showing an anomalous occipital suture, probably a remnant of the mendosal suture.

1S-19

1S-20 The Skull  |  THE OCCIPITAL BONE

FIGURE 1S-60  Striking example of asymmetric prominence of one occipitomastoid suture suggesting fracture, which is accentuated by slight rotation.

B

A

FIGURE 1S-61  A, B, Occipitomastoid sutures in frontal projections.

FIGURE 1S-63  Metopic suture simulating occipital fracture in a 22-month-old child. Note the lack of sutural serrations.

FIGURE 1S-62  The metopic suture may be seen in Towne’s projection and confused with a fracture. Note its continuation across the outline of the foramen magnum.



The Skull  |  THE OCCIPITAL BONE

1S-21

FIGURE 1S-64  Examples of occipital emissary channels.

FIGURE 1S-65  An unusual occipital emissary vein immediately above the foramen magnum.

FIGURE 1S-66  Midline vascular channel (m). Occipital venous lakes are also present (m 66).

FIGURE 1S-67  Large midline occipital venous lake.

1S-22 The Skull  |  THE OCCIPITAL BONE

FIGURE 1S-68  Other variations of occipital venous lakes.

FIGURE 1S-69  Development of occipital venous lake. The film on the right was exposed 16 years after the film on the left.

FIGURE 1S-70  Occipital venous lake with a prominent draining venous channel.



The Skull  |  THE OCCIPITAL BONE

FIGURE 1S-71  Prominent transverse venous sinuses, producing striking radiolucency in the lateral projection.

FIGURE 1S-72  Occipital midline radiolucency, probably representing a closure defect. There were no associated clinical findings.

1S-23

1S-24 The Skull  |  THE OCCIPITAL BONE

FIGURE 1S-73  The occipital bone may have a variety of symmetric and asymmetric areas of thinning near the midline (m), which may simulate erosion of the inner table. Some of them relate to the configuration of the transverse venous sinuses. It is important that the innocence of these variants be recognized. The crossed arrows (m 66) indicate the venous sinuses.

FIGURE 1S-74  Occipital thinning near the midline.

FIGURE 1S-75  Small discrete area of occipital thinning.



The Skull  |  THE OCCIPITAL BONE

1S-25

FIGURE 1S-76  Symmetric occipital thinning above the torcular in a 26-year-old woman. It has been suggested that the lucencies in this location may coincide with the occipital poles, best observed in patients with thin cranial vaults. (Ref: Newton TH, Potts DG: Radiology of the Skull and Brain, vol 1. St. Louis, Mosby, 1971.)

FIGURE 1S-77  Large asymmetric occipital thinning in a 43-year-old woman.

FIGURE 1S-78  Normal asymmetry of the condyloid canals (white arrows). A small ossicle is present in the right canal. Note also the normal irregularity of the posterior margin of the foramen magnum (crossed black arrows). (Ref: Gathier JC, Bruyn GW: The so-called condyloid foramen in the half-axial view. Am J Roentgenol Radium Ther Nucl Med 107:515, 1969.)

FIGURE 1S-79  Asymmetric condyloid fossae with a large fossa on the patient’s left (m). The condyloid canal is seen within the fossa (m 6).

1S-26 The Skull  |  THE OCCIPITAL BONE

FIGURE 1S-80  The external occipital protuberance producing a vague density superimposed on the frontal sinus.

FIGURE 1S-81  Huge external occipital protuberance.

FIGURE 1S-82  Unusual appearance produced by superimposition of external occipital protuberance and confluence of the venous sinuses.



The Skull  |  THE OCCIPITAL BONE

1S-27

FIGURE 1S-83  Simulated abnormality of foramen magnum, produced by superimposed projection of benign hyperostosis of the internal surface of the frontal bone.

FIGURE 1S-84  Two examples of normal irregularities of the margins of the foramen magnum.

1S-28 The Skull  |  THE TEMPORAL BONE

THE TEMPORAL BONE

FIGURE 1S-85  Vascular grooves in the temporal bone seen through the sphenoid sinus, simulating fractures.

FIGURE 1S-86  Skull of a 3-month-old infant, showing wormian bones in the anterior end of the squamosal suture (m). Note also the vascular groove in the parietal bone that simulates a fracture (m 6 ). The skull is rotated on its vertical axis, and the groove is projected across the coronal sutures.

FIGURE 1S-87  Convolutional impressions. The scalloping of the inner table of the middle cranial fossa is normal in adults. (Ref: Lane B: Erosions of the skull. Radiol Clin North Am 12:257, 1974.)



The Skull  |  THE TEMPORAL BONE

1S-29

FIGURE 1S-88  Two examples of temporal sutural sclerosis simulating suprasellar calcification.

FIGURE 1S-89  Focal area of sclerosis in the squamosal suture in a 76-year-old woman. FIGURE 1S-90  Temporal thinning in Stenvers’ projection simulating destruction of the calvaria.

1S-30 The Skull  |  THE TEMPORAL BONE

The Mastoid

FIGURE 1S-91  Mastoid emissary vein seen unilaterally in Towne’s projection (m). Note the prominent condyloid fossa on the opposite side (m 66).

FIGURE 1S-92  Left, Asymmetric development of the mastoids in a 5-year-old child, with marked overdevelopment in the patient’s right side. (m) Note the lucency in the midline of the occipital bone, which represents a normal variant. (m 66) Right, A detailed view of the right mastoid.

FIGURE 1S-93  Large mastoid air cell below the emissary vein simulating an area of bone destruction.

FIGURE 1S-94  Large mastoid emissary vein.



The Skull  |  THE TEMPORAL BONE

The Petrous Pyramid

FIGURE 1S-95  Two examples of normal asymmetry in height and configuration of the petrous ridges.

FIGURE 1S-96  Stenvers’ projections demonstrating large air cells at the petrous tips, simulating changes of acoustic neuromas. (Ref: Dubois PJ, Roub LW: Giant air cell of petrous apex. Radiology 129:103, 1978.)

1S-31

1S-32 The Skull  |  THE TEMPORAL BONE

FIGURE 1S-97  Asymmetric pneumatization of the petrous ridges.

FIGURE 1S-98  Unusual cochlear densities in a patient without symptoms referable to the inner ear.

FIGURE 1S-99  Dense nodular form of calcification of the petroclinoid ligament simulating asymmetric development of one petrous bone, with the dense portion seen in the lateral projection.



The Skull  |  THE TEMPORAL BONE

1S-33

FIGURE 1S-100  Left, Small, rounded bony knob on the superior margin of the petrous bones. This finding is usually unilateral but may be bilateral, as in this case. (Ref: Shapiro R: An interesting normal variant of the temporal bone. Radiology 128:354, 1978.) Right, Bony, ringlike configuration of the petrous tip.

A

B FIGURE 1S-101  Variation in development of the petrous ridges producing an anomalous “foramen” on one side. A, Plain film. B, Tomogram.

FIGURE 1S-102  The same phenomenon as in Figure 1S-101, seen here bilaterally.

1S-34 The Skull  |  THE SPHENOID BONE

FIGURE 1S-103  “Fish-mouth” internal auditory meatus on tomogram, one of the normal variations in configuration.

FIGURE 1S-104  Two examples of normal asymmetry of the configuration of the internal auditory canals. (Ref: Fraser RA, Carter BL: Unilateral dilatation of the internal auditory canal. Neuroradiology 9:227, 1975.)

THE SPHENOID BONE

FIGURE 1S-105  Marked asymmetry of the superior orbital fissures.



The Skull  |  THE SPHENOID BONE

A

1S-35

B

FIGURE 1S-106  Simulated fracture of the lesser wing of the sphenoid by anatomic variation not present on opposite side. A, Plain film. B, Tomogram.

FIGURE 1S-107  Slight rotation of the head and the superimposition of a prominent external occipital protuberance, appearing on the left, simulating the changes of a sphenoid wing meningioma.

FIGURE 1S-108  Two examples of pneumatization of the anterior clinoid processes, simulating enlargement of the optic foramina.

1S-36 The Skull  |  THE BASE OF THE SKULL

FIGURE 1S-109  Pneumatization of the sphenoid sinus extending into the greater wings of the sphenoid and producing apparent defects in the floor of the anterior fossa in the lateral projection.

THE BASE OF THE SKULL

FIGURE 1S-110  Occipitomastoid sutures in base views of the skull.



The Skull  |  THE BASE OF THE SKULL

FIGURE 1S-111  Squamosal suture in the base view.

1S-37

FIGURE 1S-112  Vascular groove in the vertex of the skull simulating a basal skull fracture.

FIGURE 1S-113  Sphenofrontal suture in a 3-month-old child.

FIGURE 1S-114  Foramen ovale with a petroalar bar. (Ref: Newton TH, Potts DG: Radiology of the Skull and Brain, vol 1. St. Louis, Mosby, 1971.)

FIGURE 1S-115  Normal asymmetry of the foramina ovale, also seen in Waters’ projection (right).

1S-38 The Skull  |  THE BASE OF THE SKULL

FIGURE 1S-116  Large carotid foramen seen unilaterally.

FIGURE 1S-117  Simulated fossae produced by attachments of the rectus capitis muscles.

FIGURE 1S-118  Foramen ovale with a pterygospinous bar. (Ref: Newton TH, Potts DG: Radiology of the Skull and Brain, vol 1. St. Louis, Mosby, 1971.)

FIGURE 1S-119  Soft tissue masses seen in the nasopharyngeal air shadow representing large pharyngeal tonsils.

FIGURE 1S-120  Large occipital condyles. Left, AP projection. Center, Lateral projection. Right, Tomogram.



The Skull  |  THE SELLA TURCICA

1S-39

FIGURE 1S-121  Basipharyngeal canal in a 10-year-old boy.

THE SELLA TURCICA

FIGURE 1S-122  Bridging of the sella in a 51⁄ 2-month-old child. FIGURE 1S-123  Sellar spine, an anatomic variant of no clinical significance. (From Dietemann JL, et al: Anatomy and radiology of the sellar spine. Neuroradiology 21:5, 1981.)

1S-40 The Skull  |  THE SELLA TURCICA

FIGURE 1S-124  Well-defined tuberculum sella turcica.

FIGURE 1S-125  Two examples of the radiolucency of a thin dorsum sellae simulating a destructive process.

FIGURE 1S-126  Mushroom configuration of the posterior clinoid processes.



The Skull  |  THE SELLA TURCICA

1S-41

FIGURE 1S-127  Normal variations in the shape of the sella turcica. Tiny sellae may normally be seen. (Ref: Swanson HA, Du Boulay G: Borderline variants of the normal pituitary fossa. Br J Radiol 48:366, 1975.)

FIGURE 1S-128  Double floor of the sella turcica, produced by filming in less than true lateral projection.

A

FIGURE 1S-129  Double floor of the sella turcica, simulated by the carotid groove.

B

FIGURE 1S-130  Double floor of the sella resulting from unequal sphenoid sinus development. A, Lateral projection. B, AP tomogram. (Ref: Bruneton JN, et al: Normal variants of the sella turcica. Radiology 131:99, 1979.)

1S-42 The Skull  |  THE SELLA TURCICA

FIGURE 1S-131  Normal variation of the sella turcica. Note the small bridged sella.

FIGURE 1S-132  Extensive pneumatization of the dorsum sellae simulating erosion.

CHAPTER

2

The Facial Bones PAGES

FIGURES

68 to 70

THE ORBITS

2-1 to 2-9

71 71 73 76 77

THE PARANASAL SINUSES The Maxillary Sinuses The Frontal Sinuses The Ethmoid Bone and Ethmoidal Sinuses The Sphenoidal Sinuses

2-10 2-10 2-19 2-27 2-31

78 to 78

THE ZYGOMATIC ARCH

2-34 to 2-35

78 to 82

THE MANDIBLE

2-36 to 2-48

82 to 83

THE NOSE

2-49 to 2-53

to to to to to

77 73 75 76 77

to to to to to

2-33 2-18 2-26 2-30 2-33

THE ORBITS

FIGURE 2-1  Normal asymmetry of the lesser wings of the sphenoid.

68

FIGURE 2-2  Pneumatization of the anterior clinoid processes simulating enlargement of the optic canals.

The Facial Bones  |  THE ORBITS

69

PART 1  |  CHAPTER 2



FIGURE 2-3  Bilateral congenital absence of the orbital processes of the zygoma.

FIGURE 2-4  Two examples of absence of the medial walls of the orbits, a finding of no clinical significance.

FIGURE 2-5  Simulated fracture through zygomaticofrontal suture produced by a slight rotation of the head.

FIGURE 2-6  Unusual appearance produced by extension of a sphenoidal air cell into the greater wing of the sphenoid.

70

The Facial Bones  |  THE ORBITS

FIGURE 2-7  Normal asymmetry of the superior orbital fissures (m). Note also the asymmetric density of the sphenoidal wings and the apparent loss of the superior medial aspect of the right orbital rim (m 66).

FIGURE 2-8  Periglobal fat, simulating air in the orbits (m). Note also the shadow of the closed eyelids (m 6).

FIGURE 2-9  Two examples of the infraorbital groove simulating a fracture of the floor of the orbit. The patient on the right has left maxillary sinusitis.

The Facial Bones  |  THE PARANASAL SINUSES

71

THE PARANASAL SINUSES The Maxillary Sinuses

FIGURE 2-10  Hypoplasia of both antra simulating sinus disease.

FIGURE 2-11  Hypoplasia of the left maxillary antrum simulating sinus disease (n).

FIGURE 2-12  Two examples of unilateral hypoplasia of the maxillary antrum. This condition may be associated with asymmetry of the superior orbital fissures. (Ref: Bassiouny A, et al: Maxillary sinus hypoplasia and superior orbital fissure asymmetry. Laryngoscope 92:441, 1982.)

FIGURE 2-13  Two examples of apparent loculation of the antra produced by lateral extension of sphenoidal sinus air cells.

PART 1  |  CHAPTER 2



72

The Facial Bones  |  THE PARANASAL SINUSES

FIGURE 2-14  Impacted third maxillary molar producing a convex density in the floor of the maxillary antrum.

FIGURE 2-15  Two examples of simulated tumor of the antrum produced by superimposition of the turbinates on the coronoid process of the mandible. (Ref: Sistrom CL, Keats TE, Johnson CM III: The anatomic basis of the pseudotumor of the nasal cavity. AJR Am J Roentgenol 147:782, 1986.)

FIGURE 2-16  Simulated fractures of the lateral wall of the maxillary antrum produced by the posterior superior alveolar canal. (Ref: Chuang VP, Vines FS: Roentgenology of the posterior superior alveolar foramina and canals. Am J Roentgenol Radium Ther Nucl Med 118:426, 1973.)

The Facial Bones  |  THE PARANASAL SINUSES

73

PART 1  |  CHAPTER 2



FIGURE 2-17  The nares superimposed on the antra simulating polyps. FIGURE 2-18  Superimposition of the upper lip on the antra simulating retention cysts.

The Frontal Sinuses

FIGURE 2-19  Overdevelopment of the frontal sinuses without associated disease.

FIGURE 2-20  Unilateral development of the frontal sinuses.

The Facial Bones  |  THE PARANASAL SINUSES

74

FIGURE 2-21  Unusual variation in pneumatization of the frontal sinus with an anomalous air cell simulating an intradiploic epidermoid.

FIGURE 2-22  Incomplete pneumatization of the anterior wall of the frontal sinus producing a pseudo-mass in the sinus.

A

B FIGURE 2-23  A, B, Incomplete aeration of the left frontal sinus simulating clouding of sinusitis.

The Facial Bones  |  THE PARANASAL SINUSES

75

PART 1  |  CHAPTER 2



FIGURE 2-24  Large lateral loculus of the frontal sinus.

A

B FIGURE 2-25  A, B, Extensive pneumatization of the floor of the anterior fossa.

FIGURE 2-26  Discrete cellule within the frontal sinus, probably arising from an ethmoidal air cell.

76

The Facial Bones  |  THE PARANASAL SINUSES

The Ethmoid Bone and Ethmoidal Sinuses

FIGURE 2-27  Remarkable overdevelopment of the ethmoidal air cells with extension into the floor of the anterior fossa.

FIGURE 2-28  Marked pneumatization of the crista galli.

FIGURE 2-29  An anomalous ethmoidal air cell in the floor of the orbit.

FIGURE 2-30  Ethmoidal cell extending into the sphenoid sinus.

The Facial Bones  |  THE PARANASAL SINUSES

The Sphenoidal Sinuses

FIGURE 2-31  Pneumatization of the pterygoid plates.

FIGURE 2-32  Unusual appearance produced by extension of a sphenoidal air cell into the greater wing of the sphenoid. (Ref: Yune HY, et al: Normal variations and lesions of the sphenoid sinus. Am J Roentgenol Radium Ther Nucl Med 124:129, 1975.)

FIGURE 2-33  Marked lateral and inferior extensions of the sphenoid sinuses.

77

PART 1  |  CHAPTER 2



78

The Facial Bones  |  THE ZYGOMATIC ARCH

THE ZYGOMATIC ARCH

FIGURE 2-34  Tomogram of the zygomatic arch showing the suture between the zygomatic bone and the zygomatic process of the temporal bone. This suture may be confused with a fracture line.

FIGURE 2-35  Simulated fracture of the zygomatic arch, produced by overlapping shadows of the base and arch of the bone.

THE MANDIBLE

FIGURE 2-36  Overlapping shadow of the tongue simulating fracture of the condyle of the mandible. (Courtesy Dr. Rahmat O. Kashef.)

The Facial Bones  |  THE MANDIBLE

79

PART 1  |  CHAPTER 2



FIGURE 2-37  Two examples of how the pharyngeal air shadows may simulate a fracture of the mandible.

FIGURE 2-38  Superimposition of the airway producing an apparent fracture of the mandibular condyle.

80

The Facial Bones  |  THE MANDIBLE

FIGURE 2-39  Simulated fracture of the ascending ramus of the mandible caused by overlapping of the coronoid process.

FIGURE 2-40  Irregularity of the mandibular angles caused by the insertion of the masseter muscles.

FIGURE 2-41  Bifid mandibular condyle. (From Loh FC, Yeo JF: Bifid mandibular condyle. Oral Surg Oral Med Oral Pathol 69:24, 1990.)

FIGURE 2-43  Entry point of the mandibular nerve simulating fracture of the mandible. FIGURE 2-42  Prominent mandibular angles simulating exostoses.

The Facial Bones  |  THE MANDIBLE

81

PART 1  |  CHAPTER 2



B

A

FIGURE 2-44  A, Coronoid process of the mandible mistaken for an osteoma. B, Basal view in another patient illustrates the origin of the density seen in (A).

FIGURE 2-45  Very large geniohyoid tubercle.

FIGURE 2-46  The mental foramen (m). Note how it can be mistaken for an apical abscess (m 6 ).

FIGURE 2-47  The dental crypt of a partially erupted molar should not be mistaken for an apical abscess.

82

The Facial Bones  |  THE NOSE

FIGURE 2-48  Crypts for the third molars in a 9-year-old child, which should not be mistaken for dental cysts.

THE NOSE

FIGURE 2-49  The normal nasal bone. Note the nasomaxillary suture (m) and the grooves for the nasociliary nerves (m 6 ). No grooves should cross the nasal bridge. (Ref: de Lacey GJ et al: The radiology of nasal injuries: Problems of interpretation and clinical relevance. Br J Radiol 50:412, 1977.)

FIGURE 2-50  Hypoplasia of the nasal bone.

FIGURE 2-51  Extra nasal bone. (Courtesy Dr. Juri Kaude.)

The Facial Bones  |  THE NOSE

83

PART 1  |  CHAPTER 2



FIGURE 2-52  Pneumatized middle turbinates (concha bullosa).

FIGURE 2-53  Turbinate air stripes.

CHAPTER

2

The Facial Bones

FIGURES

THE ORBITS

2S-1 to 2S-9

THE PARANASAL SINUSES The Maxillary Sinuses The Frontal Sinuses The Ethmoid Bone and Ethmoidal Sinuses The Sphenoidal Sinuses

2S-10 2S-10 2S-22 2S-32 2S-35

THE ZYGOMATIC ARCH

2S-39 to 2S-41

THE MANDIBLE

2S-42 to 2S-53

THE NOSE

2S-54 to 2S-56

to to to to to

2S-38 2S-21 2S-31 2S-34 2S-38

THE ORBITS

FIGURE 2S-1  Simulated destruction of the lateral wall of the orbit resulting from through-projection of the transverse venous sinus.

2S-43

2S-44 The Facial Bones  |  THE ORBITS

FIGURE 2S-2  The anterior clinoid processes superimposed on the superior orbital fissures.

A

B FIGURE 2S-3  Ethmoid air cell simulating trauma in a patient with facial trauma. A, Plain film. B, Tomogram.

FIGURE 2S-4  Asymmetric supraorbital foramina. This may be confused with a localized destruction of the orbital rim.

FIGURE 2S-5  Asymmetric supraorbital foramina.



The Facial Bones  |  THE ORBITS 2S-45

A

B FIGURE 2S-6  A, B, Two examples of normal asymmetry of the superior orbital fissures.

FIGURE 2S-7  Factitial increased density of the left orbit caused by a slight rotation of the head and a prominent superimposed external occipital protuberance.

FIGURE 2S-8  The shadow of the eyelid seen unilaterally.

FIGURE 2S-9  The edge of the superior orbital fissure, not to be mistaken for calcification in the globe.

2S-46 The Facial Bones  |  THE PARANASAL SINUSES

THE PARANASAL SINUSES The Maxillary Sinuses

FIGURE 2S-10  Hypoplasia of the maxillary antrum. Note enlargement of the orbit on the same side, a finding that frequently accompanies hypoplasia of the antrum. (Ref: Bierny JP, Dryden R: Orbital enlargement secondary to paranasal sinus hypoplasia. AJR Am J Roentgenol 128:850, 1977.)

FIGURE 2S-11  Hypoplasia of the left maxillary antrum.

FIGURE 2S-12  Hypoplasia of the antrum on the right (m). Note also the lateral extension of the left sphenoid sinus, producing an apparent loculation of the antrum (m 66).



The Facial Bones  |  THE PARANASAL SINUSES 2S-47 47

A

B

FIGURE 2S-13  Unusual development of the maxillary antra. A, Plain film. The left antrum is huge and extends far laterally. The right antrum contains at least two loculi, the medial one being deeper and more lucent than the lateral. B, Tomogram.

FIGURE 2S-14  Compartmented antra in a patient with sinusitis.

FIGURE 2S-15  Two examples of apparent loculation of the antra produced by lateral extension of sphenoidal sinus air cells.

2S-48 The Facial Bones  |  THE PARANASAL SINUSES

FIGURE 2S-16  Localized bony excrescence in roof of antrum probably caused by incomplete aeration around the infraorbital canal and foramen.

A

FIGURE 2S-17  Localized bony thickening of the lateral wall of the maxillary antrum.

B FIGURE 2S-18  Localized bony excrescence in the floor of the maxillary antrum. A, Plain film. B, Tomogram.

FIGURE 2S-19  Pseudotumor of the maxillary sinus produced by the coronoid process of the mandible.

FIGURE 2S-20  The coronoid process of the mandible in the brow-up projection, simulating an air-fluid level in the maxillary antrum.



The Facial Bones  |  THE PARANASAL SINUSES 2S-49 49

FIGURE 2S-21  Simulated soft tissue mass at the base of right maxillary antrum as a result of an exaggerated Waters’ projection.

The Frontal Sinuses

FIGURE 2S-22  Marked pneumatization of the frontal bone on CT scan.

FIGURE 2S-23  Incomplete aeration of the frontal sinus producing shadowing of the frontal sinuses. Osseous shadows are evident in the lateral projection (m).

2S-50 The Facial Bones  |  THE PARANASAL SINUSES

A

B FIGURE 2S-24  A, B, Uneven aeration of the frontal sinuses caused by irregularity of the posterior wall.

FIGURE 2S-25  Marked cephalad extension of the frontal sinus.

FIGURE 2S-26  Marked lateral extension of the frontal sinus.



The Facial Bones  |  THE PARANASAL SINUSES 2S-51 51

FIGURE 2S-27  Marked posterior extension of the frontal sinuses.

FIGURE 2S-28  Two examples of factitial clouding of the frontal sinus produced by superimposition of a large external occipital protuberance.

FIGURE 2S-29  Sclerosis of the nasofrontal suture.

FIGURE 2S-30  A sclerotic lambdoidal suture superimposed on the edge of the frontal sinus that can be mistaken for osteomyelitis.

2S-52 The Facial Bones  |  THE PARANASAL SINUSES

FIGURE 2S-31  Bowed central septum of the frontal sinus.

The Ethmoid Bone and Ethmoidal Sinuses

A

B

FIGURE 2S-32  Extension of ethmoidal cell extending into a nonaerated sphenoid sinus resulting in a mass effect in the sphenoid sinus. A, Plain film. B, Tomogram.

FIGURE 2S-33  Mild pneumatization of the crista galli (m). The arrows below (m 66) indicate the foramina rotunda.

FIGURE 2S-34  Tomogram of the ethmoidal region, showing asymmetric development of the foramina rotunda with poor definition of the lateral aspect of one of the foramina.



The Facial Bones  |  THE PARANASAL SINUSES 2S-53 53

The Sphenoidal Sinuses

FIGURE 2S-35  Apparent air-fluid level in the sphenoid sinus produced by incomplete aeration. The film was made upright but not brow-up.

FIGURE 2S-36  Left, Simulated air-fluid level in the sphenoid sinus produced by the zygomatic arch. Right, Heavier exposure shows bony detail to better advantage. (Ref: Yanagisawa E, et al: Zygomatic arch simulating an air-fluid level in the sphenoid sinus. Ear Nose Throat 56:487, 1977.)

2S-54 The Facial Bones  |  THE PARANASAL SINUSES

FIGURE 2S-37  An example of sphenoidal air cell in the greater wing of the sphenoid.

FIGURE 2S-38  Unusually marked lateral extension of the sphenoid sinuses. (Ref: Kattan KR, Potter GY: Lateral extension of sphenoid sinuses. Med Radiogr Photogr 59:9, 1983.)



The Facial Bones  |  THE ZYGOMATIC ARCH 2S-55 55

THE ZYGOMATIC ARCH

FIGURE 2S-39  The zygomaticotemporal foramen (Hyrtl’s foramen). (Ref: Yanagisawa E, Smith HW: Normal radiographic anatomy of the paranasal sinuses. Otolaryngol Clin North Am 6:429, 1973.)

FIGURE 2S-40  The suture between the zygomatic bone and the zygomatic process of the temporal bone seen in oblique projection, simulating a fracture.

FIGURE 2S-41  The zygomaxillary suture simulating a fracture in a 6-year-old boy.

2S-56 The Facial Bones  |  THE MANDIBLE

THE MANDIBLE

FIGURE 2S-42  Spurlike insertion of the temporomandibular ligament.

A

B FIGURE 2S-43  A, Pharyngeal air shadow over the base of the tongue superimposed on the mandible simulates a fracture. B, Panoramic (Panorex) radiograph made at same session shows that no fracture is present.



The Facial Bones  |  THE MANDIBLE 2S-57 57

FIGURE 2S-44  The mandibular canal simulating calcification in soft tissues.

B

A

FIGURE 2S-45  Simulated fractures of the coronoid processes produced by superimposition of the lateral pterygoid plates.

FIGURE 2S-46  Prominent submandibular fossae, which should not be mistaken for areas of bone destruction.

2S-58 The Facial Bones  |  THE MANDIBLE

FIGURE 2S-47  The foramen ovale projected through the ascending ramus of the mandible.

A

FIGURE 2S-48  Bifid mandibular condyle. (From Loh FC, Yeo JF: Bifid mandibular condyle. Oral Surg Oral Med Oral Pathol 69:24, 1990.)

B

FIGURE 2S-49  A, Simulated destructive lesion of the mandible produced by rotation at time of filming. B, Improved positioning corrects the apparent lesion.



The Facial Bones  |  THE MANDIBLE 2S-59 59

FIGURE 2S-50  Lucencies in the ascending ramus of the mandible caused by fossae.

FIGURE 2S-51  The normal mental foramina.

FIGURE 2S-52  Prominent mandibular canals.

FIGURE 2S-53  The earlobes visualized by panoramic (Panorex) radiograph.

2S-60 The Facial Bones  |  THE NOSE

THE NOSE

FIGURE 2S-54  Simulated fracture of the nasal bone produced by the shadow of the superimposed coronal suture in an exaggerated Waters’ projection. (Ref: Emberton P, Finlay DB: Letter to the editor. Clin Radiol 43:217, 1991.)

FIGURE 2S-55  Concha bullosa on CT scans.



The Facial Bones  |  THE NOSE 2S-61 61

FIGURE 2S-56  Left, Waters’ projection suggesting a mass in the nasal passage produced by a large inferior turbinate. Right, The nature of the mass effect is evident in Caldwell’s projection.

CHAPTER

3

The Spine PAGES

FIGURES

84 to 188

THE CERVICAL SPINE

3–1 to 3–251

189 to 204

THE THORACIC SPINE

3–252 to 3–296

204 to 237

THE LUMBAR SPINE

3–297 to 3–388

238 to 249

THE SACRUM

3–389 to 3–424

250 to 252

THE COCCYX

3–425 to 3–435

253 to 256

THE SACROILIAC JOINTS

3–436 to 3–446

THE CERVICAL SPINE

FIGURE 3-1  Note the remarkable apparent separation of the base of the skull and cervical spine in this 4-year-old child, not to be mistaken for craniovertebral separation. This appearance is most often seen in children younger than this subject.

84

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85

PART 1  |  CHAPTER 3



A

C

B

D

FIGURE 3-2  The neural canal in the infant is proportionately larger than in the adult. This difference is often overlooked in the infant and may be misinterpreted as a manifestation of pathologic expansion of the spinal canal. A, B, 4-month-old infant. C, D, 18-year-old man.

86

The Spine  |  THE CERVICAL SPINE

A

C

B

D

FIGURE 3-3  Enlargement of the cervical canal with no evidence of cervical cord lesions in normal children. A, B, Plain films showing marked enlargement of cervical canal. C, D, Myelograms showing large dural sac with normal cord. The same phenomenon may also be seen in the thoracic spine. (Ref: Yousefzadeh DK, et al: Normal sagittal diameter and variation in the pediatric cervical spine. Radiology 144:319, 1982.)

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87

PART 1  |  CHAPTER 3



A

B FIGURE 3-4  A, Prominent occipital condyles. B, The articulation between the occipital condyles and the lateral masses of C1.

FIGURE 3-5  Absence of ossification in the anterior arch of C1 in a neonate. This is a normal finding in many neonates. (Ref: Dedick AP, Caffey J: Roentgen findings in the skull and chest in 1030 newborn infants. Radiology 61:13, 1953.)

88

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FIGURE 3-6  Left, Apparent absence of the anterior arch of C1 in a 29-month-old child. Ordinarily, this should be evident by 12 months of age. Right, CT scan shows a small ossific nucleus for the anterior arch.

A

B

C

FIGURE 3-7  Absence of the anterior arch of C1. The left lateral condyle is huge (m); the right is hypoplastic. A, Lateral radiography. B, AP tomogram. C, CT scan.

FIGURE 3-8  Occipital vertebra; the third condyle (m). A unilateral paracondylar process is present and articulates with the transverse process of the atlas (m 66). (Ref: Lombardi G: The occipital vertebra. Am J Roentgenol Radium Ther Nucl Med 86:260, 1961.)

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PART 1  |  CHAPTER 3



FIGURE 3-9  A smaller third occipital condyle.

A

B FIGURE 3-10  Assimilation of a left occipital vertebra. A, Lateral projection. B, Coronal CT scan.

FIGURE 3-11  Complete incorporation of C1 into the base of the skull (assimilation of the atlas).

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90

B

A

C FIGURE 3-12  Partial incorporation of C1 into the base of the skull. Note the incomplete segmentation of C1–C2 as well. A, Plain film. B, C, CT sections.

FIGURE 3-13  Partial incorporation of C1 into the base of the skull to a lesser degree than pictured in Figure 3-12. Note also the similar incomplete segmentation of C2–C3.

FIGURE 3-14  Uptilted neural arch of C1.

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91

PART 1  |  CHAPTER 3



FIGURE 3-15  Anomalous articulation between the posterior arch of C1 and the base of the skull.

A

B FIGURE 3-16  A, B, An anomalous articulation of base of skull on CT scans.

92

The Spine  |  THE CERVICAL SPINE

FIGURE 3-17  Three examples of anomalous articulation between the posterior arch of C1 and the base of the skull.

FIGURE 3-18  Paracondylar process arising from the occipital bone.

FIGURE 3-19  Epitransverse process arises from the transverse process of the atlas and projects cranially toward the occipital condyle. It is a mirror image of the paracondylar process. The epitransverse process may be unilateral or bilateral and may coexist with the paracondylar process. (Ref: Shapiro R, Robinson F: Anomalies of the craniovertebral border. AJR Am J Roentgenol 127:281, 1976.)

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PART 1  |  CHAPTER 3



FIGURE 3-20  Bony spur arising from the base of the skull, simulating a neural arch (m). Note the arcuate foramina for the vertebral arteries (m 6).

FIGURE 3-21  Two examples of accessory bony elements between the base of the skull and the neural arch of C1.

A

B

FIGURE 3-22  A, Normal cleft in the neural arch of the axis in a 1-year-old child. B, Normal clefts in the neural arches of all the cervical vertebrae in an 11-month-old child. These neurocentral synchondroses may persist until 3 to 6 years of age, and one side may remain open for several months after the other side has closed. (Ref: Swischuk LE, et al: The dens-arch synchondrosis versus the hangman’s fracture. Pediatr Radiol 8:100, 1979.)

94

The Spine  |  THE CERVICAL SPINE

FIGURE 3-23  Incomplete closure of the neural arch of C1 in a 2-year-old child. These arches normally close at 3 to 6 years of age.

FIGURE 3-24  Two examples of absence of the posterior arch of C1. Note the marked overgrowth of the spinous process of C2. (Ref: Dalinka MK, et al: Congenital absence of the posterior arch of the atlas. Radiology 103:581, 1972.)

FIGURE 3-25  Absence of the laminae of C1. (Ref: Logan WW, Stuard ID: Absent posterior arch of the atlas. Am J Roentgenol Radium Ther Nucl Med 118:431, 1973.) This entity is not necessarily innocent and may be associated with instability. (Ref: Schulze PJ, Buurman R: Absence of the posterior arch of the atlas. AJR Am J Roentgenol 134:178, 1980.)

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95

PART 1  |  CHAPTER 3



FIGURE 3-26  Two examples of incomplete formation of the posterior neural arch of C1.

FIGURE 3-27  Two examples of incomplete development of the neural arch of C1 in infants.

FIGURE 3-28  Incomplete formation of the posterior arch of C1 with spina bifida occulta seen in the frontal projection (m).

96

The Spine  |  THE CERVICAL SPINE

FIGURE 3-29  Left, Incomplete development of the neural arch of C1 simulating a fracture. Right, CT scan shows partial formation on the right side of the neural arch.

A

B

FIGURE 3-30  A, B, Incomplete formation of the neural arch of C1, seen best in the occipital view (A).

FIGURE 3-31  Air in the pinna (m) simulating a fracture of the neural arch of C1 (m 6 ).

FIGURE 3-32  The lobe of the ear superimposed on the anterior arch of C1.

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97

PART 1  |  CHAPTER 3



FIGURE 3-33  Unilateral spondylolysis of C1 with sclerosis at the site of the lysis, best seen in the center figure (m).

A

B

C FIGURE 3-34  An appearance similar to that in Figure 3-33 may be produced by faulty positioning. A, Apparent defects in neural arch of C1 in offlateral projection. B, Defects not seen in true lateral projection. C, CT scan shows the neural arch to be intact.

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98

A

B FIGURE 3-35  Spondylolysis of C1 seen in off-lateral projection (A) but not in true lateral projection (B).

A

C

B

D

FIGURE 3-36  The arcuate foramina formed by calcification of the oblique atlantooccipital ligaments. The vertebral arteries pass through these foramina. A, Complete foramen. B, Incomplete foramen. C, D, Calcification in the oblique atlantooccipital ligaments forming incomplete arcuate foramina.

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99

PART 1  |  CHAPTER 3



FIGURE 3-37  Normal exaggerated density of the posterior elements of C1 in a 7-year-old girl (left) and a 15-year-old girl (right).

FIGURE 3-38  Sclerotic neural arch of C1 in an adult.

A

B

FIGURE 3-39  Absence of the spinolaminar line at C1 secondary to spina bifida occulta. A, Lateral projection. B, CT scan.

100

The Spine  |  THE CERVICAL SPINE

A

B

FIGURE 3-40  Failure of the spinolaminar line at C2, probably related to the large size of the neural arch. A, Lateral projection. B, CT scan.

FIGURE 3-41  Anomalous articulation between the spinous processes of C1 and C2.

FIGURE 3-42  Normal position of the anterior process of C1 (m), with relationship to the odontoid (m 6 ) when head is in extension. This may be mistaken for a post-traumatic event.

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PART 1  |  CHAPTER 3



FIGURE 3-44  Tipped axis of C1 with high position of the anterior arch and low position of the neural arch.

FIGURE 3-43  High position of the anterior arch of C1 may be seen in normal individuals, even with the head in neutral position.

A

B

FIGURE 3-45  A, Double contours of the anterior aspects of C1 and C2 as a result of rotation. B, Normal appearance with proper positioning.

102

The Spine  |  THE CERVICAL SPINE

A

B

FIGURE 3-46  The dens–C1 interval normally increases with the head in flexion, particularly in children. A, Flexion. B, Neutral position. (Ref: Locke GR, et al: Atlas-dens interval (ADI) in children: A survey based on 200 normal cervical spines. Am J Roentgenol Radium Ther Nucl Med 97:135 1966.) The V-shaped predens space is a normal variation and does not necessarily indicate damage to the transverse ligament. (Ref: Bohrer SP, Klein A, et al: V-shaped predens space. Skeletal Radiol 14:111, 1985.)

FIGURE 3-47  The dens–C1 interval may change in flexion and extension in this 10-year-old boy. This interval tends to remain fixed in adults. Note the shift of the posterior laminar line as well. (Ref: Swischuk LE: The cervical spine in childhood. Curr Probl Diagn Radiol 13:1, 1984.)

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PART 1  |  CHAPTER 3



FIGURE 3-48  Accessory ossicle posterior to C1, articulating with the neural arch of C1.

A

FIGURE 3-49  Osseous processes above and below the posterior arch of C1.

B FIGURE 3-50  Unusual appearance of the anterior arch of C1 secondary to closure defects in the anterior and posterior neural arches.

A

B

FIGURE 3-51  Unusual contour of the anterior arch of C1 with a spurlike configuration and double contour. A, Lateral projection. B, CT scan.

104

The Spine  |  THE CERVICAL SPINE

FIGURE 3-52  Huge anterior arch of C1 in the absence of other anomalies.

FIGURE 3-53  Huge anterior process of C1. (Courtesy Dr. R.L. Stern.)

FIGURE 3-54  Accessory ossicles above the anterior process of C1. (Ref: Lombardi G: The occipital vertebra. Am J Roentgenol Radium Ther Nucl Med 86:260, 1961.)

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105

PART 1  |  CHAPTER 3



A

B

FIGURE 3-55  A, Simulated ossicle at the tip of the odontoid joint produced by the mastoid tip. B, Ossicle not seen in anteroposterior projection.

FIGURE 3-56  Examples of calcification of the anterior longitudinal ligament above the anterior process of C1.

FIGURE 3-57  Calcification of the anterior longitudinal ligament above and below the anterior process of C1. Left, A 14-year-old boy. Right, A 44-year-old man. In older individuals, these kinds of changes may be associated with degenerative arthritis of the atlantoodontoid joint. (Ref: Genez BM, et al: CT findings of degenerative arthritis of the atlantoodontoid joint. AJR Am J Roentgenol 154:315, 1990.)

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106

C

B

A

D

E

FIGURE 3-58  Five examples of the variable appearance of the accessory ossicle of the anterior arch of the atlas. This ossicle forms an articulation with the inferior aspect of the anterior arch; that articulation may be confused with a fracture. The ossicle should not be confused with calcific tendinitis of the longus colli muscle. (Ref: Haun CL: Retropharyngeal tendinitis. AJR Am J Roentgenol Radium Ther Nucl Med 130:1137, 1978.) (From Keats TE: Inferior accessory ossicle of the anterior arch of the atlas. Am J Roentgenol Radium Ther Nucl Med 101:834, 1967.)

A

B

FIGURE 3-59  An unusual ossicle of the anterior arch of C1. Note the displacement of the retropharyngeal soft tissues. A, Lateral projection. B, Tomogram.

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PART 1  |  CHAPTER 3



A

B

FIGURE 3-60  Identical ossicle at anterior arch of C1 shown to lie between the lateral masses of C1 and C2 on coronal reformatted CT scan (B).

FIGURE 3-61  Constellation of ossicles and ligamentous calcification below the anterior arch of C1 in a 35-year-old woman.

FIGURE 3-62  Fragmented anterior arch of C1.

108

The Spine  |  THE CERVICAL SPINE

FIGURE 3-63  Left, Ear lobe simulating calcific tendinitis of the longus colli muscle. Right, The ear lobes identified with metallic markers to confirm the nature of the shadow seen in the left figure.

A

B FIGURE 3-64  Asymmetry of the lateral masses of C2 with short odontoid and large neural arches.

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109

PART 1  |  CHAPTER 3



A

B

FIGURE 3-65  Normal variations in the appearance of the lateral masses of C1. A, Spurlike configurations of the medial borders. B, Foramen-like configuration of the medial borders. C, Pseudofracture. These variants should not be mistaken for manifestations of trauma. (Ref: Meghrouni V, Jacobson G: The pseudonotch of the atlas. Radiology 72:260, 1959.)

C

A

B

FIGURE 3-66  A, Plain film. B, CT Scan. Pneumatization of the lateral mass of C1 simulating a destructive lesion. (From Moss M, et al: Complications of occipital bone pneumatization. Australas Radiol 48:259, 2004.)

110

The Spine  |  THE CERVICAL SPINE

FIGURE 3-68  Marked elongation of the transverse processes of C1. FIGURE 3-67  Pseudonotch of the atlas mistaken for a fracture. These notches form the attachment site of the transverse ligament.

FIGURE 3-69  Two examples of developmental bilateral offsets of the lateral masses of C1 and C2 in children. This appearance in an adult would be presumptive evidence of a fracture of the neural arch of C1. This entity is believed to be secondary to a disparity of growth of the atlas and axis vertebrae in children and is most commonly seen in children approximately 4 years old. (Ref: Suss RA, Zimmerman RD, Leeds NE: Pseudospread of the atlas: False sign of Jefferson fracture in children. AJR Am J Roentgenol 140:1079, 1983.)

FIGURE 3-70  Developmental bilateral offset of the lateral masses of C1 on C2 may persist in older children as well, as seen in this 6-year-old.

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PART 1  |  CHAPTER 3



FIGURE 3-71  Offsets of C1 and C2, which may simulate Jefferson’s burst fracture, may be seen in patients with incomplete neural arches. This patient has a spina bifida occulta of C1 posteriorly.

FIGURE 3-72  Unilateral offset of the left lateral mass C1 is associated with spina bifida occulta of the neural arch of C1.

A

B FIGURE 3-73  A, Plain Film. B, CT Scan. Hypoplastic C1 with medial position of the lateral masses.

112

The Spine  |  THE CERVICAL SPINE

FIGURE 3-74  Spina bifida occulta of C1 seen in the open-mouth view of the odontoid process.

A

B

FIGURE 3-75  Normal ossification centers for the tip of the odontoid process (m). This center appears at age 2 years and fuses at age 12 years. A, A 5-year-old boy. B, A 7-year-old boy. Minor variations in the width of the interval between the odontoid process and the lateral masses, as shown in B, are caused by rotation of the head at the time of filming and should not be mistaken for evidence of trauma (m 66). (Ref: Wortzman G, Dewar FP: Rotary fixation of the atlantoaxial joint: Rotational atlantoaxial subluxation. Radiology 90:479, 1968.)

FIGURE 3-76  Ossification of the tip of the odontoid process (os terminale) in frontal and lateral projections in a 9-year-old boy.

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PART 1  |  CHAPTER 3



A

B FIGURE 3-77  A, Overlapping of the mastoid simulating erosion of the odontoid. B, CT scan shows no abnormality.

FIGURE 3-78  Mach effect produced by the shadow of the tongue, simulating an un-united ossification center of the tip of the odontoid process.

114

The Spine  |  THE CERVICAL SPINE

A

B FIGURE 3-79  Calcification of the apical ligament of the odontoid. A, Lateral projection. B, Reformatted CT scan.

FIGURE 3-80  The midline cleft in the odontoid is usually closed at birth. It has persisted in this 4-year-old boy. (Ref: Ogden JA: Radiology of postnatal skeletal development. XII: The second cervical vertebra. Skeletal Radiol 12:169, 1984.)

FIGURE 3-81  Normal synchondrosis of the base of the odontoid process in a child.

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PART 1  |  CHAPTER 3



B

A

FIGURE 3-82  Synchondrosis at the base of the odontoid process may be mistaken for a fracture in children. The junction usually closes by age 7. A, A 2-year-old child. B, A 3-year-old child.

FIGURE 3-83  Persistence of a portion of the odontoid synchondrosis in a 9-year-old boy.

FIGURE 3-84  Residuals of the odontoid synchondrosis in a 23-year-old woman.

FIGURE 3-85  Residuals of the odontoid synchondrosis in a 28-year-old woman.

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FIGURE 3-86  Sclerosis of the odontoid synchondrosis and asymmetry of the odontoid process.

A

B

FIGURE 3-87  Fusion of the anterior arch of C1 to the odontoid process in a 3-year-old boy. A, Plain film. B, Tomogram. (Ref: Olbrantz K, Bohrer SP: Fusion of the anterior arch of the atlas and dens. Skeletal Radiol 12:21, 1984.)

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FIGURE 3-88  Pseudofracture portion of the base of the odontoid produced by superimposition of the lateral masses of C2.

A

B

FIGURE 3-89  Anterior tilt of the odontoid is not necessarily secondary to fracture in pediatric patients. A, Lateral projection in a 2-year-old child. B, Sagittal reformation shows normal-appearing subdental synchondrosis. (Ref: Rhea JT: Anterior tilt of the odontoid: Is it always a sign of fracture? Emerg Radiol 2:109, 1995.)

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FIGURE 3-90  Normal developmental clefts at the base of the odontoid process, remnants of the synchondrosis.

A

B FIGURE 3-91  Congenital absence of the odontoid in a child.

FIGURE 3-92  Congenital absence of the odontoid process and posterior arch of C1 detected as an incidental finding. Note characteristic overdevelopment of the anterior arch of C1, seen in congenital absence of the odontoid process and in failure of union of the odontoid process. (Ref: Swischuk LE, et al: The os terminale–os odontoideum complex. Emerg Radiol 4:72, 1997.)

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A

B

FIGURE 3-93  A, B, Os odontoideum resting in the original synchondrosis. This case indicates that os odontoideum is sometimes developmental in origin and not secondary to trauma. (Refs: Roback DL: Neck pain, headache, and loss of equilibrium after athletic injury in a 15-year-old boy. JAMA 245:963, 1981; Dawson LG, Smith L: Atlantoaxial subluxation in children caused by vertebral anomalies. J Bone Joint Surg Am 61:582, 1979.)

FIGURE 3-94  Two additional examples (two views each) of os odontoideum. Note the overgrowth of the anterior arch of C1. The hypertrophy of the anterior arch is a useful sign in differentiating os odontoideum from acute dens fracture. (Ref: Holt RG, et al: Hypertrophy of C1 anterior arch: Useful sign to distinguish os odontoideum from acute dens fracture. Radiology 173:207, 1989.)

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A

B FIGURE 3-95  Os odontoideum with terminal segment.

FIGURE 3-96  Left, Simulated os odontoideum produced by the lateral masses of C1. Center, Tomogram shows the lateral mass that produces the apparent discontinuity of the odontoid. Right, Tomogram shows no os odontoideum.

FIGURE 3-97  Odontoid hypoplasia (m) with large occipital condyles (m 6). (Ref: McManners T: Odontoid hypoplasia. Br J Radiol 56:907, 1983.)

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FIGURE 3-98  Odontoid hypoplasia. This entity may be associated with C1–C2 instability.

FIGURE 3-99  Hypoplastic odontoid process with inclination to the left and asymmetry of the lateral masses. Note the remnant of the synchondrosis at the base (m).

A

B

C

FIGURE 3-100  Persistent infantile odontoid process in an 18-year-old man. This variation produces the broad base of the odontoid process in A, the simulated fracture in B, and the broad-based odontoid process in C. A, B, Tomograms. C, CT scan. The asymmetrics of the base of the odontoid illustrated in the following six figures are products of this type of development. (Ref: McClellan R, et al: Persistent infantile odontoid process: A variant of abnormal atlantoaxial segmentation. AJR Am J Roentgenol 158:1305, 1992.)

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FIGURE 3-101  An additional example of persistent infantile odontoid process.

FIGURE 3-102  Simulated fracture of the odontoid resulting from persistent infantile odontoid process.

FIGURE 3-103  Two examples of anomalous development of base of the odontoid process. Note the corresponding deformity of the lateral masses of C1.

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FIGURE 3-104  Asymmetric development of the occipital condyles, the lateral masses of C2, and the odontoid process. There is also incomplete segmentation of C2 and C3.

A

B

FIGURE 3-105  A, B, Asymmetry of the odontoid and lateral masses of C2 in the absence of rotation secondary to asymmetric development of the articular facets of C2.

FIGURE 3-106  Unusual configuration of the tip of the odontoid process (m). Note also the normal asymmetry of the atlantoaxial joints as a result of the positioning of the head (m 66).

FIGURE 3-107  Turbinal configuration of tip of the odontoid process.

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FIGURE 3-108  Four examples of posterior inclination of the odontoid process that should not be confused with fracture. Note characteristic high position of the anterior arch of C1. (Ref: Swischuk LE, et al: The posterior tilted dens: Normal variation mimicking a fractured dens. Pediatr Radiol 8:27, 1979.)

FIGURE 3-109  Two examples of ossicles around the tip of the odontoid process.

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FIGURE 3-110  Large ossicle at the tip of the odontoid process.

A

B

FIGURE 3-111  A, Normal asymmetry of the intervals between the odontoid process and the lateral masses of C1, produced by rotation of the head. B, Same patient with head in neutral position.

FIGURE 3-112  Left, The effect of tilting of the head to the right. The atlas has glided to the right side. The space between lateral mass and the dens on the left has decreased, whereas that on the right has widened. The lateral margins of the lateral atlantoaxial joint spaces are asymmetric (m). The spinous processes are deviated to the left. Right, CT scan shows the corresponding asymmetry of the spaces between the lateral masses of C1 and the dens. (Ref: Harris JH, Edeiken-Monroe B: The Radiology of Acute Cervical Spine Trauma, 2nd ed. Baltimore, Williams & Wilkins, 1987.)

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FIGURE 3-113  Altered relationships between the lateral masses of C1 and the odontoid process resulting from combined rotation and tilting of the head.

FIGURE 3-114  Pseudofractures of the odontoid process produced by overlapping shadows of the central maxillary incisors.

FIGURE 3-115  Two examples of the lucency between the maxillary central incisors superimposed on the odontoid process and simulating a split odontoid.

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FIGURE 3-116  Simulated cleft in the odontoid process produced by midline closure defect in the anterior arch of the atlas.

A

B

FIGURE 3-117  Closure defect in the anterior arch of C1, producing an apparent fracture of the odontoid process. A, Open-mouth view of the odontoid process. B, CT scan. (Ref: Chalmers AG: Spondyloschisis of the anterior arch of the atlas. Br J Radiol 58:761, 1985.) Closure defects may be present in the anterior and posterior arches in the same patient, resulting in a bipartite atlas vertebra. (Ref: Saifuddin A, Renwick GH: Case of the month: A pain in the neck. Br J Radiol 66:379, 1993.) The bipartite atlas may also demonstrate hypertrophy of the anterior arch. (Ref: Walker J, Biggs I: Bipartite atlas and hypertrophy of its anterior arch. Acta Radiol 36:152, 1995.)

FIGURE 3-118  Deep median sulcus of the tongue superimposed on the odontoid simulating a vertical fracture of the odontoid.

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FIGURE 3-119  Pseudofractures of the base of the odontoid process produced by the Mach effect from overlapping shadows of the posterior arch of C1, the tongue, or the occiput. Each was proven a pseudofracture by tomography. (Ref: Daffner RH: Pseudofracture of the dens: Mach bands. AJR Am J Roentgenol 128:607, 1977.)

FIGURE 3-120  Pseudofracture of the odontoid process produced by a vascular groove in the skull.

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B

A

FIGURE 3-121  A, Mach effect from shadows of the lips producing a simulated fracture. B, Reexamination shows no evidence of fracture.

FIGURE 3-123  Pseudofracture of the body of C2 produced by overlapping pharyngeal soft tissue shadows. FIGURE 3-122  Remnants of the synchondroses of the primary ossification centers of C2 (m). Note also the pseudofracture of the base of the odontoid process (m 6).

A

B FIGURE 3-124  Coronal cleft of C2 in a 7-month-old infant, a transient developmental variant. A, Lateral projection. B, CT scan.

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FIGURE 3-126  The C2 “target” composite shadow is a projectional variant not formed by a single anatomic structure. (Ref: Nicolet V, et al: C-2 “target”: Composite shadow. AJNR Am J Neuroradiol 5:331, 1984.) Disruption of the ring shadow is a good indication of a low type (type III) odontoid fracture. (Ref: Harris JH, et al: Low (type III) odontoid fracture: A new radiographic sign. Radiology 153:353, 1984.)

FIGURE 3-125  Additional example of coronal clefting of C2 in a 6-monthold infant.

FIGURE 3-127  In the younger patient, the C2 target shadow may appear as several rings, as shown in this 13-year-old boy.

A

B

FIGURE 3-128  A, Duplication of the ring shadows of C2 caused by obliquity (m). B, True lateral projection reduces the appearance.

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A

B FIGURE 3-129  A, B, Spina bifida C2 simulating a fracture.

FIGURE 3-130  Pseudofracture of C2 produced by overlapping of large uncinate processes. (Ref: Daffner R: Pseudofracture of the cervical vertebral body. Skeletal Radiol 15:295, 1986.)

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FIGURE 3-131  Very large uncovertebral processes in a 33-year-old woman.

A

B

FIGURE 3-132  The superimposed lobe of the ear may produce shadows that can simulate a fracture (m). Note in B the cleft in the anterior aspect of the vertebral body, which is probably a remnant of the synchondrosis for the odontoid process (m 6 ).

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FIGURE 3-133  Left, Many patients exhibit a shallow groove at the superior aspect of the neural arch of C2 (m) that could be mistaken for a hangman’s fracture. Right, In flexion, these grooves are seen bilaterally. The physiologic subluxation of C2 on C3 reinforces the impression of a hangman’s fracture.

FIGURE 3-134  The grooves illustrated in Figure 3-133 can also be demonstrated by CT.

FIGURE 3-135  Cleft or groove simulating a fracture of C2.

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A

B

C

D FIGURE 3-136  A, B, Clefts in the laminae of C2 can be confused with fractures on CT. C, D, The same entity in more exaggerated form.

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FIGURE 3-137  Two 1-year-old children with spondylolysis of C2 originally diagnosed as hangman’s fractures. Hangman’s fracture is very uncommon in children, but spondylolysis of C2 is not. CT confirmation should be obtained to make the differentiation in the emergency situation. (Refs: Parisi M, et al: Hangman’s fracture or primary spondylolysis: A patient and a brief review. Pediatr Radiol 21:367, 1991; Riebel G, Bayley JC: A congenital defect resembling the hangman’s fracture. Spine 16:1240, 1991; Smith JT, et al: Persistent synchondrosis of the second cervical vertebra simulating hangman’s fracture in a child: Report of a case. J Bone Joint Surg Am 75:1228, 1993; Mondschein J, Karasick D: Spondylolysis of the axis vertebra: A rare anomaly simulating hangman’s fracture. AJR Am J Roentgenol 172:556, 1999.)

A

B

FIGURE 3-138  Spondylolysis of C2 in a 3-year-old with Down syndrome, showing spondylolisthesis on flexion. A, Neutral position. B, flexion.

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A

B FIGURE 3-139  A, B, Two examples of spondylolysis of C2 in adults.

FIGURE 3-140  Spondylolysis of C3 with hypoplasia of the left lateral mass.

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A

B

FIGURE 3-141  A, Unilateral closure defect in the lamina on the left side of C2. B, Right side shown for comparison.

FIGURE 3-142  Simulated fracture of C2 produced by slight rotation with superimposition of the superior articular process on the vertebral body.

FIGURE 3-143  Unusual development of C2 with ossicle arising from anterior vertebral body.

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FIGURE 3-144  Hypoplasia of C2 with hypertrophy of the posterior elements of C3 and an anomalous articulation with the neural arch of C3.

FIGURE 3-145  Anomalous ossicle between the spinous processes of C2 and C3. Left, Plain film. Right, Tomogram.

FIGURE 3-146  Fissure in the spinous process of C2 simulating a fracture. The white arrow indicates the arcuate foramen.

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FIGURE 3-147  In some patients, the C2 vertebra is larger in its inferior portions than the adjacent C3 vertebra, giving a pseudo “fat C2 sign” that suggests a vertical C2 body fracture. (Ref: Smoker WR, Dolan KD: The “fat C2”: A sign of fracture. AJNR 8:33, 1987.) FIGURE 3-148  Partial nonsegmentation of C2 and C3.

FIGURE 3-149  Anomalous articulation between C2 and C3.

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A

B FIGURE 3-150  A, Simulated fusion of posterior elements of C2 and C3 produced by rotation. B, Repeat film shows no abnormality at C2–C3, but apparent fusion appears at C5 and C6. In some patients, this pseudofusion is the result of oblique orientation of the facets with reference to the x-ray beam. (Ref: Massengill AD, et al: C2–C3 facet joint “pseudo-fusion”: Anatomic basis of a normal variant. Skeletal Radiol 26:27, 1997.)

FIGURE 3-151  The foramen transversarium. The central density is a portion of the vertebra projected through the lucency of the foramen.

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A

B

FIGURE 3-152  A, Asymmetric foramina transversarium producing lucencies in the C2 vertebral body (m). B, CT scan demonstrates incomplete foramen on left.

FIGURE 3-153  Nonsegmented C2–C3 with characteristic calcification in the rudimentary disc.

FIGURE 3-154  Three examples of incomplete segmentation that is commonly called congenital block vertebra. Occasionally, this finding may predispose the patient to early degenerative spondylosis at the next lower intervertebral disc. (Ref: de Graaff R: Vertebrae C2–C3 in patients with cervical myelopathy. Acta Neurochir 61:111, 1982.)

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FIGURE 3-155  Incomplete segmentation of C2–C3 with a huge irregular foramen between the neural arches.

FIGURE 3-156  Partial segmentation of C2–C3 originally diagnosed as a fracture.

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A

B

FIGURE 3-157  A, B, Block vertebrae are often associated with defects in architecture. Note the failure of fusion of the lateral mass of C2 in the anteroposterior film (m). Rarely, this anomaly may be associated with radiculopathy. (Ref: Okada K, et al: Cervical radiculopathy associated with an anomaly of the cervical vertebrae: A case report. J Bone Joint Surg Am 70:1399, 1988.)

FIGURE 3-158  Nonsegmentation of C3 and C4 with asymmetric development of the pedicles.

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A

B FIGURE 3-159  Partial segmentation of C2–C3 (A) with spina bifida (B) in a 9-year-old child.

A

B

FIGURE 3-160  A, Pseudosubluxation of C2 on C3 in a 6-year-old boy. This is the normal area of maximum movement in the child; pseudosubluxation is regularly seen in flexion. B, A view with the head in neutral position shows normal relationships. (Ref: Jacobson G, Beeckler HH: Pseudosubluxation of the axis in children. AJR Am J Roentgenol 82:472, 1959.)

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FIGURE 3-161  Another example of pseudosubluxation of C2 on C3 in a 4-year-old boy. Note the neck in flexion. The spinolaminar line is useful in differentiating true subluxation from pseudosubluxation of C2 on C3. (Ref: Swischuk LE: Anterior displacement of C2 in children: Physiologic or pathologic. Radiology 122:759, 1977.)

A

B

FIGURE 3-162  Physiologic subluxation of C2 on C3 may also occur in adults. A, A 20-year-old man. B, A 34-year-old woman. (Ref: Harrison RB, et al: Pseudosubluxation of the axis in young adults. J Can Assoc Radiol 31:176, 1980.)

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FIGURE 3-163  Normal variations in the curvature of the cervical spine, depending on head position in the same patient on the same day. Such variations should not necessarily be taken as evidence of post-traumatic muscle spasm.

A

B

FIGURE 3-164  Marked physiologic subluxation of C2 on C3, C3 on C4, and C4 on C5 with flexion in a 13-year-old boy. Note that the spinolaminar line is intact. A, Flexion. B, Extension.

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A

B

FIGURE 3-165  Physiologic subluxation may occur at multiple levels in flexion, particularly in children. A, Note the anterior subluxation of C2 on C3, C3 on C4, and C4 on C5 in a child. Spinolaminar line is intact. B, Normal alignment in neutral position. (Ref: Swischuk LE: The cervical spine in childhood. Curr Probl Diagn Radiol 13:1, 1984.)

FIGURE 3-166  Left, Multiple physiologic subluxations on flexion in a 9-year-old boy. Center, Neutral position. Right, Extension.

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A

B

D C FIGURE 3-167  A, B, Physiologic anterior “slipping” of cervical vertebrae on flexion (A) and correction on extension (B). C, D, Physiologic posterior “slipping” of cervical vertebrae on extension (C) and correction on flexion (D). These minor degrees of “malalignment” with extremes of motion are not necessarily abnormal in themselves, particularly if the “slipping” occurs at multiple levels in continuity. (Ref: Scher AT: Anterior subluxation: An unstable position. AJR Am J Roentgenol 133:275, 1979.)

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B

A

FIGURE 3-168  A, An example of the simulated fracture of the posterior neural arch of C3 produced by rotation. B, Corrected position. No fracture is seen.

A

B

FIGURE 3-169  A, Simulated fracture of the neural arch of C3 produced by rotation. B, Repeat examination with correction of rotation shows restitution to normal appearance. Note also the absence of a lordotic curve in A. This is a common variation, especially between ages 8 and 16 years. (Ref: Cattell HS, Filtzer DL: Pseudosubluxation and other normal variations in the cervical spine in children: A study of one hundred and sixty children. J Bone Joint Surg Am 47:1295, 1965.)

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A

B

C FIGURE 3-170  Simulated fracture of C2 produced by rotation. A, Apparent fracture with slight rotation. B, Suspected lesion not seen with improved positioning. C, CT scan shows no abnormality.

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FIGURE 3-171  Backward “displacement” of the spinolaminar line at C2 is a normal variation in both children and adults and should not be mistaken for evidence of subluxation. (Ref: Kattan K: Backward “displacement” of the spinolaminal line at C2: A normal variation. AJR Am J Roentgenol 129:289, 1977.)

FIGURE 3-172  Left, Pseudofracture of the inferior articulating process of C3. Right, True lateral projection shows that the pseudofracture is caused by the overlapping shadows of the inferior articulating processes.

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FIGURE 3-174  Absence of the posterior elements of C2.

FIGURE 3-173  An example of notochordal remnants of the cervical spine at C2–C4.

A

B

FIGURE 3-175  Wide spacing between spinous processes of C3 and C4, which might be misconstrued as evidence of flaring caused by soft tissue injury. Note the lack of change between flexion (A) and neutral position (B). This pseudofanning occurs most commonly at C3–C4.

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A

B

C FIGURE 3-176  Spondylolysis of the neural arch of C4 simulating a fracture. A, Lateral plain film. B, Tomogram. C, CT scan. (Ref: Forsberg DA, et al: Cervical spondylolysis: Imaging findings in 12 patients. AJR Am J Roentgenol 154:751, 1990.)

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FIGURE 3-177  Absence of portions of the posterior arch of C4.

A

B

C FIGURE 3-178  Osseous articulation between the transverse processes of C3 and C4 originally diagnosed as an osteochondroma. A, AP view. B, CT scan of C3. C, CT scan of C4.

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FIGURE 3-179  Normal wedge shape of juvenile cervical vertebral bodies, which should not be confused with compression fractures.

FIGURE 3-180  Wedge-shaped vertebral bodies in a 13-year-old boy. Note particularly the marked wedging of C3, which was mistaken for a compression fracture. (Ref: Swischuk LE, et al: Wedging of C3 in infants and children: Usually a normal finding and not a fracture. Radiology 188:523, 1993.)

FIGURE 3-181  Normal retention of wedged configuration of C3 (m) in a 54-year-old woman. Note also that the base of the spinous process of C2 (m 6 ) lies slightly posterior to that of C1 and C3. (m 66) This is a normal variation that may be seen in children as well and should not be mistaken for evidence of subluxation. (Ref: Kattan KR: Backward “displacement” of the spinolaminal line at C2: A normal variation. AJR Am J Roentgenol 129:289, 1977.)

FIGURE 3-182  Unusual configuration of C3. Tomography showed no evidence of a fracture.

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FIGURE 3-183  Anterior and posterior ring apophyses of the vertebrae. (Ref: Nanni G, Hudson JM: Posterior ring apophyses of the cervical spine. Am J Roentgenol 139:383, 1982.)

FIGURE 3-184  Un-united ossification centers at the inferior articular process of C4 (left and center). Un-united ossification centers of the fifth and sixth cervical vertebrae, which simulate fracture (limbus vertebrae) (right).

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A

B

C

FIGURE 3-185  Simulated jumped facet at C4 produced by absence of pedicle on the right. A, Lateral projection. B, Reformatted CT scan showing absence of the pedicle. C, Reformatted CT scan of opposite side.

FIGURE 3-186  Normal wedged appearance of C5 in a 33-year-old man that should not be mistaken for a compression fracture. Note the absence of condensation of bone or buckling of the anterior cortex. (Refs: Kattan K, Pais MJ: Some borderlands of the cervical spine. I: The normal (and nearly normal) that may appear pathologic. Skeletal Radiol 8:1, 1982; and Kim KS, et al: Pitfalls in plain film diagnosis of cervical spine injuries: False positive interpretation. Surg Neurol 25:381, 1986.)

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FIGURE 3-187  Four additional examples of unusual configurations of C5 that might be misconstrued as evidence of trauma.

A

C

B

D

FIGURE 3-188  A through D, Four examples of simulated fractures of C5 in young patients without symptoms in this location, caused by Schmorl’s nodes. Note the gas in the anterior aspect of the disc in (D). It is possible that these anterior disc herniations may produce the wedged configuration of C5 in adults illustrated in the preceding two figures. (Ref: Paajanen H, et al: Disc degeneration in Scheurmann disease. Skeletal Radiol 18:523, 1989.)

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B

A FIGURE 3-189  A, B, The same entity as in Figure 3-188 demonstrated on reformatted CT scan.

FIGURE 3-191  The normal secondary ossification centers of the vertebrae in a 14-year-old boy.

FIGURE 3-190  Unusual contour of C5.

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FIGURE 3-192  Closing secondary ossification centers in a 16-year-old boy.

FIGURE 3-193  Three examples of cervical limbus vertebrae. When these elements appear in an adult, they probably represent calcification in the annulus fibrosus secondary to stress. (Ref: Kerns S, et al: Annulus fibrosus calcification in the cervical spine: Radiologic-pathologic correlation. Skeletal Radiol 15:605, 1978.)

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FIGURE 3-194  Two examples of pseudoenlargement of the neutral foramen as a result of superimposition of both margins of the foramen. Note the two margins of pedicle (m).

FIGURE 3-195  Un-united ossification center of the inferior articular process of C6.

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FIGURE 3-196  A bifid spinous process (m) can project into the neural foramen and simulate a fracture (m 6).

FIGURE 3-197  An example of the confusing appearance of the neural foramina (m), produced by bifid spinous processes (m 6).

FIGURE 3-198  A bifid spinous process in the horizontal plane.

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FIGURE 3-199  Abortive spondylolysis of C5.

A

B

C

FIGURE 3-200  Anomalous articulation between the transverse processes of C4 and C5. A, Lateral projection. B, Right posterior oblique projection. C, Left posterior oblique projection for comparison with B.

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B

A

FIGURE 3-201  A, Plain film. Simulated fracture of the right lateral mass of C5 resulting from a short lamina on that side. Note that the facets are not in the same plane and that the spinous process is not in the midline. B, CT scan.

A

B FIGURE 3-202  Developmental deviation of the spinous processes at C4 and C5. A, AP projection. B, CT scan.

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E

A

B

C

D

F

FIGURE 3-203  Congenital absence of the pedicle on the left at C5 (m). Compare the oblique projection (C) with the normal side (D). E, CT scan shows an absence of pedicle and spina bifida occulta. F, CT scan shows the facets to be in opposite planes; this can be seen in (A) as well. (Ref: Wiener MD, et al: Congenital absence of a cervical spine pedicle: Clinical and radiologic findings. AJR Am J Roentgenol 155:1037, 1990.)

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A

B

C

D

FIGURE 3-204  Absent pedicle at C5. A, B, AP and oblique views show a widened intervertebral foramen at C5 with absence of the pedicle on the left. C, CT scan shows an absence of the pedicle on the left and spina bifida of the spinous process. D, Axial T1-weighted MR image of a similar case with an absence of the right pedicle shows widened cerebrospinal fluid space on the right. (Ref: Edwards MG, et al: Imaging of the absent cervical pedicle. Skeletal Radiol 20:325, 1991.)

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A

B FIGURE 3-205  Simulated jumped facet at C6 produced by absence of the pedicle on the left side. A, Lateral projection. B, CT scan.

FIGURE 3-206  Hemivertebra (butterfly vertebra) at C6.

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A

B

FIGURE 3-207  Simulated fracture of C5 as a result of elongated transverse process, more evident in (A) because of rotation and less evident in true lateral projection (B).

FIGURE 3-208  Anomalous articulation between transverse processes of C5 and C6 caused by elongation of the anterior tubercle. (Ref: Applebaum Y, et al: Elongation of the anterior tubercle of a cervical vertebral transverse process: An unusual variant. Skeletal Radiol 10:265, 1983.)

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FIGURE 3-209  Anomalous articulation between the transverse processes of C5 and C6 (m) with CT myelogram confirmation.

A

B FIGURE 3-210  Anomalous osseous structure in the superior cornua of the thyroid cartilage.

170

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FIGURE 3-211  Upturned spinous process interpreted as evidence of ligamentous injury with flaring of the spinous processes.

FIGURE 3-212  Three examples of the variability of vertebral body size in a given individual.

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FIGURE 3-213  Unusually tall bodies of C6 and C7.

FIGURE 3-214  Three examples of the normal variability of size and configuration of spinous processes.

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FIGURE 3-215  Bifid spinous processes of C5 and C6, which may be mistaken for fractures.

FIGURE 3-216  Ossification of the posterior longitudinal ligament. This finding may or may not be significant. (Ref: Minagi H, Gronner AT: Calcification of the posterior longitudinal ligament: A cause of cervical myelopathy. Am J Roentgenol Radium Ther Nucl Med 105:365, 1969.)

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A

B

FIGURE 3-217  A, Simulated ossification of the posterior spinal ligament, produced by rotation, not seen with correct positioning (B).

FIGURE 3-218  Huge ossified ligamentum nuchae.

FIGURE 3-219  Ossification of the ligamentum nuchae.

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FIGURE 3-220  Un-united apophysis of the spinous process of C6 with an anomalous articulation.

FIGURE 3-221  Three examples of normal elongation of the transverse processes of C5 and C6, producing an unusual appearance anterior to the vertebral bodies (see Figure 3–207). (Ref: Lapayowker MS: An unusual variant of the cervical spine. Am J Roentgenol Radium Ther Nucl Med 83:656, 1960.)

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FIGURE 3-222  Oblique projection of the cervical spine showing the anterior tubercle of the transverse process, the structure responsible for the shadows in Figure 3-221.

FIGURE 3-223  Increased density of the body of C6 produced by an enlarged and elongated transverse process on the left, confirmed on CT scan.

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A

B

FIGURE 3-224  A, Increased density of C6 produced by overlying soft tissues. B, Density disappears when the cervical spine is extended and reduces the soft tissue overlying the vertebra.

FIGURE 3-225  Simulated fractures of vertebral bodies produced by the shadows of the transverse processes.

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A

B FIGURE 3-226  Block vertebrae at C5–C6 with spina bifida.

178

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FIGURE 3-227  Nonsegmented vertebrae at C3–C4 and C5–C6. Oblique projections show resulting deformities of intervertebral foramina.

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FIGURE 3-228  Block vertebrae of C6–C7 with marked elongation of the spinous processes.

A

B

FIGURE 3-229  Failure of the spinolaminar line at C6 in the absence of fracture, a variation of normal. A, Lateral projection. B, CT scan. (Ref: Caswell KL: Failure of the spinolaminar line at C6–C7: A normal variant. Emerg Radiol 8:91, 2001.)

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FIGURE 3-230  Two examples of developmental spurlike processes arising from the posterior portion of the neural arches of C5 and C6.

FIGURE 3-231  Two examples of normal notching of the apophyseal joint surfaces of the lower cervical spine, not to be mistaken for erosion or fracture. (Ref: Keats TE, Johnstone WH: Notching of the lamina of C7: A proposed mechanism. Skeletal Radiol 7:273, 1982.)

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FIGURE 3-232  Left, The laminar notch at C7. Right, In extension, note how the inferior articular process of C6 fits into the notch.

A

B

FIGURE 3-233  Notches in the tips of the superior articulating processes of C6 and C7, presumably developmental, detected as an incidental finding. A, Plain film. B, Tomogram.

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FIGURE 3-234  Simulated fracture of C5 produced by uncovertebral joint degeneration. (Ref: Goldberg RP, et al: The cervical split: A pseudofracture. Skeletal Radiol 7:267, 1982.)

FIGURE 3-235  Multiple pseudofractures produced by degeneration of the facet and uncovertebral joints and by rotation in the lateral projection.

FIGURE 3-236  Air in the pyriform sinuses simulating destructive lesions of the cervical spine.

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FIGURE 3-237  Three examples of simulated destructive lesions of the lower cervical spine, produced by projection.

A

B FIGURE 3-238  Spina bifida of C7 simulating a fracture. A, Plain film. B, Tomogram.

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FIGURE 3-239  Spina bifida of C7 with double spinous processes.

FIGURE 3-240  Anomalous bridge between the spinous processes of C6 and C7.

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A

B FIGURE 3-241  The omovertebral bone between C5 and T1, unassociated with Sprengel’s deformity.

A

B

C

D

FIGURE 3-242  A through C, Congenital absence of the C7 pedicle on the right (m). A spina bifida occulta is also present (m 6). Compare oblique projection (C) with normal side (D). This congenital lesion may be mistaken for an acquired one (see Figure 3–203). (Refs: Chapman M: Congenital absence of a pedicle in a cervical vertebra (C6). Skeletal Radiol 1:65, 1976; and van Dijk Azn R, et al: The absent cervical pedicle syndrome: A case report. Neuroradiology 29:69, 1987.)

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FIGURE 3-243  Failure of union of the apophysis of the tip of the spinous process of C7 simulating a fracture.

A

B

FIGURE 3-244  Failure of union of the apophysis of the tip of the spinous process of C7 with inferior displacement of the apophysis. A, Lateral projection. B, CT scan shows truncation of the spinous process.

FIGURE 3-245  Closure defect in the foramen transversarium at C7.

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FIGURE 3-246  The facet between C7 and T1.

FIGURE 3-247  Three examples of failure of the spinolaminar line at C7 in the absence of fracture, a variation of normal. This variant may be associated with incomplete segmentation of the cervical vertebrae. (Ref: Ehara S: Relationship of elongated anterior tubercle to incomplete segmentation in the cervical spine. Skeletal Radiol 25:243, 1996.)

A

B FIGURE 3-248  A, Marked failure of the spinolaminar line at C7. B, CT scan shows no fracture.

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FIGURE 3-249  Cervical rib on the left and elongated transverse process on the right at C7.

A

B FIGURE 3-250  Cervical rib on the left articulating with the first rib. A, Lateral projection. B, Oblique projection.

FIGURE 3-251  Apparent enlargement of the body of C6 caused by superimposition of the glenoid.

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189

THE THORACIC SPINE

FIGURE 3-252  The normal “bone in bone” appearance of the thoracic vertebrae in a neonate.

FIGURE 3-253  Normal thoracic spine of a 1-month-old baby. The “bone in bone” appearance is present, and the large central notches on the anterior surface of the vertebrae are normal at this age.

FIGURE 3-254  Normal neonatal thoracic spine, showing “sandwich” appearance as a result of large venous sinuses.

PART 1  |  CHAPTER 3



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FIGURE 3-255  The dense end plates of the vertebral bodies produce an unusual appearance in the frontal film of a 4-month-old child.

FIGURE 3-256  Prominent residual venous sinus “holes” in older child’s thoracic spine.

FIGURE 3-257  Normal thoracic spine of a 5-year-old child. The vascular stripes in the center of the anterior portion of the vertebral body and the notches in the anterior corners of the vertebrae are normal at this age.

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FIGURE 3-258  The appearance of the venous grooves in the frontal projection of a newborn.

FIGURE 3-259  Four examples of residual venous sinus grooves in adults.

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A

B

FIGURE 3-260  Normal “step” defects on the anterior surfaces of juvenile vertebrae. A, A 4-year-old child. B, A 7-year-old child.

FIGURE 3-261  Un-united ossification centers at the distal ends of the transverse processes of T1 in an adult.

FIGURE 3-262  Two examples of unilateral persistence of the ossification centers of the transverse processes in young adults.

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FIGURE 3-263  Unfused apophyses of the transverse processes of T1 (m) and at the medial ends of the first ribs (m 6) in a 14-year-old boy.

FIGURE 3-264  Failure of union of the apophysis for the tip of the spinous process of T1.

FIGURE 3-265  Failure of the spinolaminar line at T1.

FIGURE 3-266  Apparent narrowing of interpedicular distance at the thoracolumbar junction in a 2-week-old infant produced by the normal thoracolumbar kyphosis and resultant magnification effect.

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FIGURE 3-267  Narrow pedicles on a developmental basis in a young woman. FIGURE 3-268  Delicate bone structure in a young woman with thin pedicles simulating pedicular erosion.

FIGURE 3-269  Minor scoliosis producing simulated pedicle erosion.

FIGURE 3-270  Localized scoliosis simulating pedicle erosion.

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FIGURE 3-271  Asymmetry of the pedicles of the lower thoracic spine. This is seen as a normal variation in 7% of normal individuals. The measured interpediculate distance does not exceed two standard deviations from the mean in this normal variation. (Ref: Benzian SR, et al: Pediculate thinning: A normal variant at the thoracolumbar junction. Br J Radiol 44:936, 1971.) FIGURE 3-272  Pedicle thinning at the thoracolumbar junction may be extreme and may even be associated with concave medial borders. The absence of pertinent clinical findings should suggest this recognized normal variation. (Ref: Charlton OP, et al: Pedicle thinning at the thoracolumbar junction: A normal variant. AJR Am J Roentgenol 134:825, 1980.)

FIGURE 3-273  Sclerotic vertebral end plates in a healthy 14-year-old boy.

FIGURE 3-274  Spina bifida occulta of C7 and T1 with double spinous processes.

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FIGURE 3-275  Spina bifida of T1 simulating a fracture.

FIGURE 3-276  Left, Bulbous spinous process of T11 simulating a mass. Right, Detailed view shows identity of the shadow.

FIGURE 3-277  A, B, Large osteophyte mistaken for a mediastinal mass.

A

B

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FIGURE 3-278  Spina bifida of T11 and T12.

A

FIGURE 3-279  Limbus vertebra at T10 in a 24-year-old man.

B

C

D FIGURE 3-280  Example of degeneration of the costovertebral articulation, which is a cause of pulmonary pseudolesion. A, Frontal film. B, Lateral projection. C, Oblique projection. D, CT scan. (From Leibowitz RT, Keats TE: Degeneration of the costovertebral articulation: A cause of pulmonary pseudolesion. Emerg Radiol 10:250, 2004.)

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FIGURE 3-281  Two examples of failure of segmentation of the thoracic vertebrae. Partial development of the intervertebral discs is seen. This should not be confused with the effects of inflammatory spondylitis.

FIGURE 3-282  Congenital butterfly vertebra. Note overgrowth of the adjacent vertebra.

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PART 1  |  CHAPTER 3



FIGURE 3-283  Butterfly vertebrae at T6 and T7.

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FIGURE 3-284  Butterfly vertebra at T12 simulating a lucent lesion in the lateral projection.

FIGURE 3-285  Asymptomatic calcification of the nucleus pulposus in a young adult. This is generally asymptomatic. When it occurs in the cervical region in children, it may be associated with signs and symptoms but is self-limited. (Ref: Melnick JC, Silverman FN: Intervertebral disk calcification in childhood. Radiology 80:399, 1963.)

FIGURE 3-286  Pseudofractures of the thoracic spine. A, Superimposition of the glenoid process of the scapula on the thoracic spine, simulating a vertebral compression fracture. B, Pseudofracture of the second thoracic vertebra produced by superimposition of the superior margin of the manubrium.

A

B

The Spine  |  THE THORACIC SPINE

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PART 1  |  CHAPTER 3



FIGURE 3-287  Two examples of how the facet joints of the spine may simulate bulging annuli or paraspinous masses.

FIGURE 3-288  Anomalous articulation between the transverse processes of T3 and T4.

FIGURE 3-289  Anomalous articulation between T5 and T6 that can be seen in the lateral projection as well.

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FIGURE 3-290  Left, Anomalous articulation between the transverse processes of T11 and T12, which was mistaken for a mediastinal mass. Right, Spot film shows the anomalous articulation.

FIGURE 3-292  Bilateral styloid processes of T9.

FIGURE 3-291  Apparent destructive lesions of the rib (m), produced by superimposition of the spinous process (m 66).

FIGURE 3-293  Developmental notch in the inferior articulating process of T12 is a common anatomic variant at this level.

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PART 1  |  CHAPTER 3



FIGURE 3-294  Thoracic notochordal remnants in a 15-year-old boy.

A

B

C

FIGURE 3-295  A, Target pedicle of T12. This appearance is produced by superimposition of the shadows of the inferior and lateral tubercles on the shadow of the pedicle. B, Absence of pedicle at T12. Frontal film shows absence of the pedicular ring shadow. C, Absence of pedicle at T12. Tomogram shows absence of the pedicle (see normal pedicles above and below). (Refs: Ehara S, et al: Target pedicle of T12: Radiologic–anatomic correlation. Radiology 174:871, 1990; Manaster BJ, Norman A: CT diagnosis of thoracic pedicle aplasia. J Comput Assist Tomogr 7:1090, 1983; Lederman RA, Kaufman RA: Complete absence and hypoplasia of pedicles of the thoracic spine. Skeletal Radiol 15:219, 1986.)

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FIGURE 3-296  Huge thoracic pedicles.

THE LUMBAR SPINE

FIGURE 3-297  The normal “bone in bone” appearance of the neonate.

The Spine  |  THE LUMBAR SPINE

205

PART 1  |  CHAPTER 3



FIGURE 3-299  Normal vascular channels of the lumbar vertebral body on CT scan.

FIGURE 3-298  Two examples of coronal cleft vertebrae in neonates. These occur more commonly in males and most often in the lumbar region.

FIGURE 3-300  Lumbar bone island. (Ref: Resnik D, et al: Spinal enostosis [bone islands]. Radiology 147:373, 1983.)

FIGURE 3-301  Lumbar bone island.

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A

B

FIGURE 3-302  A, Sclerotic band resulting from vascular channel in a lumbar vertebra. B, Confirmation by T1-weighted MR image.

FIGURE 3-303  CT scan of developmental retrosomal cleft on the left. Note the anterior location of the defect, in contrast to the typical more posterior location of the defect in spondylolysis. This entity is probably of no clinical significance and should not be mistaken for a traumatic pedicle fracture. (Ref: Johansen JG, et al: Retrosomatic clefts: Computed tomographic appearance. Radiology 148:472, 1983.)

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PART 1  |  CHAPTER 3



FIGURE 3-304  Lumbar bone island simulating a sclerotic pedicle on the frontal view.

A

E

B

C

D

F

FIGURE 3-305  Congenitally wide thoracolumbar spinal canal unassociated with neurologic signs or symptoms. A, B, Plain films of large canal with thin pedicles. C, D, Myelograms showing the large dural sac. E, F, CT scans of the large spinal canal. (Ref: Patel NP, et al: Radiology of lumbar vertebral pedicles: Variants, anomalies and pathologic conditions. Radiographics 7:101, 1987.)

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A

B

FIGURE 3-306  Another example of thin lumbar pedicles as a normal variant. A, AP view shows flat pedicles with medial concavity and wide interpediculate distance throughout the lumbar spine. B, CT scan at L2 shows the thin pedicles. There is no intraspinal mass. Myelogram showed a large dural sac. (Ref: Atlas S, et al: Roentgenographic evaluation of thinning of the lumbar pedicles. Spine 18:1190, 1993.)

FIGURE 3-307  Duplication of the pedicles of L1.

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PART 1  |  CHAPTER 3



A

B FIGURE 3-308  Notochordal remnants demonstrated by CT.

FIGURE 3-309  Two examples of notochordal remnants producing “balloon” discs. (Ref: Tsuji H, et al: Developmental “balloon” discs of the lumbar spine in healthy subjects. Spine 10:907, 1985.)

210

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FIGURE 3-310  Central radiolucency within the body of L4, an incidental finding probably representing a notochordal remnant.

A

B

C FIGURE 3-311  Notochordal remnant at L5. A, AP film shows a defect in the vertebral body. B, CT scan shows a central defect. C, T2-weighted MR image shows a high signal in the area of defect.

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211

PART 1  |  CHAPTER 3



FIGURE 3-312  Unusual contour of the posterior aspect of the superior end plates of the lumbar vertebra. FIGURE 3-313  Incomplete closure of the neural arches in the lower thoracic and upper lumbar spine.

FIGURE 3-314  Partial hemivertebra that was mistaken for a calcified intervertebral disc. Note the deformities of adjacent vertebral bodies.

212

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FIGURE 3-315  “Butterfly” lumbar vertebra.

FIGURE 3-316  Another case of hypoplastic vertebra on the left. Note the hypoplastic pedicle on the left side. (Ref: McMaster MJ, David CV: Hemivertebra as a cause of scoliosis. A study of 104 patients. J Bone Joint Surg 68:588, 1986.)

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A

B

C

FIGURE 3-317  Hypoplastic vertebra producing the characteristic appearance in the lateral projection. A, AP projection. B, Lateral projection. C, CT scan.

FIGURE 3-318  Bilateral styloid processes of L1.

FIGURE 3-319  Unilateral styloid process of L1.

214

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FIGURE 3-320  Bilateral styloid process of L4. These accessory processes arise posterior to the base of the superior articular facet.

FIGURE 3-321  Unilateral styloid process of L4 (m). Note normal “Cupid’s bow” configuration of inferior plate of L4 (m 6), a normal variation. (Ref: Dietz GW, Christensen EE: Normal “Cupid’s bow” contour of the lower lumbar vertebrae. Radiology 121:577, 1976.)

FIGURE 3-323  Absence of the transverse process of the left side of L1.

FIGURE 3-322  Simulated fractures of the transverse processes, produced by the crossing shadows of the psoas muscles.

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PART 1  |  CHAPTER 3



FIGURE 3-325  Asymmetric development of L1 with a rib on the right and a transverse process on the left. FIGURE 3-324  Bilateral unconnected ribs at L1.

FIGURE 3-326  Un-united transverse processes of L1. Note attenuated sites of origin from the neural arch. The patient has an acute fracture of the vertebral body.

FIGURE 3-327  Ptotic transverse process of L3. This variant may easily be mistaken for a fracture.

FIGURE 3-328  Ptotic transverse processes.

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FIGURE 3-330  Asymmetric transverse processes with an enlarged process on the right. FIGURE 3-329  Congenital absence of the transverse process on the left side of L4.

FIGURE 3-331  Developmental bridge between the transverse processes of L3 and L4.

FIGURE 3-332  Anomalous articulation between the transverse processes of L3 and L4.

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PART 1  |  CHAPTER 3



FIGURE 3-333  Two examples of pseudarthrosis between the transverse processes of L3 and L4. (Ref: Yoslow W, Becker MH: Osseous bridges between the transverse processes of the lumbar spine: Report of three cases and review of the literature. J Bone Joint Surg Am 50:513, 1968.)

FIGURE 3-334  Transverse process of L3 seen in cross-section.

FIGURE 3-336  Lumbar rib.  (Courtesy Dr. Gary M. Guebert.)

FIGURE 3-335  Cephalad-directed transverse process of L4.

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FIGURE 3-337  Large osseous bridge joining L1, L2, and L3 in a patient with no history of trauma, simulating a lumbar rib.

FIGURE 3-338  Two examples of lumbar ribs.

FIGURE 3-339  Two examples of heavy ossification of the iliolumbar ligaments.

The Spine  |  THE LUMBAR SPINE

219

PART 1  |  CHAPTER 3



FIGURE 3-340  Un-united secondary ossification center of the end of the superior articulating process of L5.

FIGURE 3-341  Persistent apophysis of the mammillary process of L4.

FIGURE 3-342  Un-united apophysis of superior articulating process of L4.

FIGURE 3-343  Un-united ossification center of the end of the inferior articulating process of L3, which may be mistaken for a fracture. A, Frontal projection. B, Oblique projection.

A

B

220

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FIGURE 3-344  Un-united ossification center of the inferior articulating process of L3.

FIGURE 3-345  Bilateral failure of union of the ossification centers of the inferior articulating processes of L3.

FIGURE 3-346  Absence of the inferior articulating process of L3. (Refs: Arcomano JP, Karas S: Congenital absence of the lumbosacral articular processes. Skeletal Radiol 8:133, 1982; Phillips MR, Keagy RD: Congenital absence of lumbar articular facets with computerized axial tomography documentation. Spine 13:676, 1988.)

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PART 1  |  CHAPTER 3



FIGURE 3-347  Pseudospondylolysis seen at L2 and L3 in perfectly positioned lateral projections results from superimposition of the transverse processes. Left, Pseudospondylolysis at L2 and L3 in a true lateral projection. Center, The defects disappear when a minor degree of obliquity is present. Right, Pseudospondylolysis in an infant. (From El-Khoury GY, et al: Normal roentgen variant: Pseudospondylolysis. Radiology 139:72, 1981.)

A

B

FIGURE 3-348  Pseudospondylolysis at L2 and L3 in a 54-year-old man with slight rotation at the time of filming (A), which was corrected by better positioning (B).

FIGURE 3-349  Simulated spondylolysis of L4 caused by superimposition of the shadow of the crest of the ilium.

222

The Spine  |  THE LUMBAR SPINE

A

B

FIGURE 3-350  A, Bowel gas simulating spondylolysis of L2. B, Repeat examination clarifies the issue.

FIGURE 3-351  “Pig snout” pedicle results from superimposition of the shadows of the pedicle and an unusual downward projection of the distal end of the transverse process. (Courtesy Dr. W.E. Litterer.) (Ref: Patel NP, et al: Radiology of lumbar vertebral pedicles: Variants, anomalies, and pathologic conditions. Radiographics 7:101, 1981.)

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PART 1  |  CHAPTER 3



FIGURE 3-352  “Elephant nose” pedicle at L3.

FIGURE 3-353  The two-eyed Scotty dog. The second “eye” is created by a prominent mammillary process. (Ref: Resnik CS, et al: The two-eyed Scotty dog: A normal anatomic variant. Radiology 149:680, 1983.)

FIGURE 3-354  Asymmetry of the facets of the lumbar spine simulating masses.

224

The Spine  |  THE LUMBAR SPINE

A

B

FIGURE 3-355  Congenital absence of the left pedicle of L3. A, Plain film. B, CT scan. (Ref: Wortzman G, Steinhardt MI: Congenitally absent lumbar pedicle: A reappraisal. Radiology 152:713, 1984.)

FIGURE 3-356  Anomalous foramen in the neural arch of a lumbar vertebra.

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PART 1  |  CHAPTER 3



A

B

C

D

FIGURE 3-357  Absence of the lamina on the left of L4 (n). Note that the pedicle on the right is enlarged. A, AP projection. B, Lateral projection. C, Right posterior oblique projection. D, Left posterior oblique projection.

226

The Spine  |  THE LUMBAR SPINE

A

B

FIGURE 3-358  A, Simulated destruction of the pedicle on the right side of L4, produced by scoliosis. B, Tomogram shows pedicle to be intact.

FIGURE 3-359  Scalloping of the posterior aspects of the vertebral bodies may be seen as a normal variant, particularly in childhood. Left, A 6-yearold child. Right, A 10-year-old child.

FIGURE 3-360  Scalloping of the posterior aspects of the vertebral bodies in an asymptomatic 21-year-old man. This variation may also be seen in patients with spinal stenosis.

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PART 1  |  CHAPTER 3



A

B

FIGURE 3-361  A, The bodies of T12 and L1 are often slightly wedge-shaped. B, Another example of normal wedging of the bodies of T12, L1, and L2.

FIGURE 3-362  Long lumbar vertebrae. FIGURE 3-363  Oversized lumbar vertebra.

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228

FIGURE 3-364  Bulbous configuration of the body of L1 in a 3-year-old child.

A

B

C

FIGURE 3-365  Spurred osteoporotic vertebra may produce an appearance suggesting pathologic destruction. A, Plain film. B, C, Tomograms. (Ref: Wagner A: “Spurious” defect of the lumbar vertebral body. AJR Am J Roentgenol 135:1095, 1980.)

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PART 1  |  CHAPTER 3



FIGURE 3-366  Multiple spurious defects of the lumbar spine in an 83-year-old woman.

A

B FIGURE 3-367  A, B, Bifid spinous process of L4.

230

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FIGURE 3-368  Ossification of the supraspinous ligament in an 81-year-old man. These foci of ossification are an aging phenomenon and should not be mistaken for an avulsion fracture. (Ref: Scapinelli R: Localized ossifications in the supraspinous and interspinous ligaments of adult man. Rays 13:29, 1988.)

A

B

C

FIGURE 3-369  Degenerative changes in the lumbar spinous processes with aging. With marked lordosis and loss of height of the intervertebral discs, the spinous processes come into contact and eventually develop hypertrophic degenerative changes in these pseudarthroses. This development, which has been termed “kissing spinous processes” or Baastrup’s disease, may be symptomatic. A, AP view shows enlargement of the spinous processes, particularly at L4. B, The posterior articulation and the enlarged spinous processes produce an unusual appearance that might be mistaken for bone destruction. C, Tomogram shows the sclerosis of the margins of the spinous processes and the relative radiolucency of the nonarticulating portions. (Ref: Jacobson HG, et al: The “swayback” syndrome. Am J Roentgenol Radium Ther Nucl Med 79:677, 1958.)

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A

B

FIGURE 3-370  Un-united secondary ossification center (limbus vertebra) simulating a fracture of L5. A, Plain film. B, Laminagram. There is evidence to suggest that limbus vertebrae are the result of intravertebral disc herniation. (Refs: Kozlowski K: Anterior intravertebral disc herniations in children: Unrecognized chronic trauma to the spine. Australas Radiol 23:67, 1979; Henales V, et al: Intervertebral disc herniations [limbus vertebrae] in pediatric patients: Report of 15 cases. Pediatr Radiol 23:608, 1993.)

FIGURE 3-371  Other examples of un-united secondary lumbar ossification center (limbus vertebrae).

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FIGURE 3-372  The ring apophysis of L5 seen in its entirety in an 8-year-old girl.

A

B

FIGURE 3-373  A, Normal posterior “stepping” of lumbar vertebrae on extension. B, Normal alignment in neutral position.

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PART 1  |  CHAPTER 3



FIGURE 3-374  Wedge shape of L5 and bowing of the inferior end plates are normal variations and not reflections of pathology. (Ref: Dietz GW, Christensen EE: Normal “Cupid’s bow” contour of the lower lumbar vertebrae. Radiology 121:577, 1976.)

FIGURE 3-375  Wedge configuration of L5 in a patient with no history of prior trauma and no evidence of fracture.

FIGURE 3-376  Apparent reverse spondylolisthesis of L5 on S1. The apparent displacement is usually caused by errors in positioning. In some individuals, it results from the fact that the AP diameter of the superior surface of the sacrum is smaller than the inferior surface of the fifth lumbar vertebra. The anterior relationships are more reliable. (Ref: Melamed A, Ansfield DJ: Posterior displacement of lumbar vertebrae. Am J Roentgenol Radium Ther Nucl Med 58:307, 1947.)

FIGURE 3-377  Left, Apparent retrospondylolisthesis of L5 on S1 as a result of rotation. Right, True lateral projection shows normal relationships.

234

The Spine  |  THE LUMBAR SPINE

B

A

C FIGURE 3-378  Large L4-L5 facets, a developmental variation in a 20-year-old man. A, Frontal projection. B, C, Oblique projections.

A

B

C

FIGURE 3-379  Simulated spondylolysis of L5 on the left created by short inferior articulating process seen in C. A, AP projection. B, Left oblique projection. C, Right oblique projection.

The Spine  |  THE LUMBAR SPINE

235

PART 1  |  CHAPTER 3



A

B FIGURE 3-380  Growth arrest lines in a 16-year-old boy.

FIGURE 3-381  Articulation between transverse processes of L4 and L5.

FIGURE 3-382  Anomalous “ribs” at L5.

236

The Spine  |  THE LUMBAR SPINE

FIGURE 3-383  Bilateral sacralization of L5 with anomalous articulations with the sacrum.

FIGURE 3-384  Unilateral sacralization of L5 on left side. Note the additional density created in the lateral projection. The anomalous articulation should not be mistaken for a fracture.

FIGURE 3-385  Two other examples of anomalous articulations between L5 and the sacrum. This anatomic arrangement may become symptomatic. (Ref: Jonsson B, et al: Anomalous lumbosacral articulations and low back pain: Evaluation and treatment. Spine 14:831, 1989.)

The Spine  |  THE LUMBAR SPINE

237

PART 1  |  CHAPTER 3



FIGURE 3-386  Anomalous articulation between the transverse process of L5 and the adjacent sacrum.

FIGURE 3-387  Patients with transitional vertebrae often have a significantly narrower lumbosacral disc than those with no transitional features. This narrowing does not imply disc degeneration. This finding is illustrated in a patient with six lumbar vertebrae. (Ref: Nicholson AA, et al: The measured height of the lumbosacral disc in patients with and without transitional vertebrae. Br J Radiol 61:454, 1988.)

FIGURE 3-388  Ossification of the iliolumbar ligament.

238

The Spine  |  THE SACRUM

THE SACRUM

FIGURE 3-389  An un-united ossification center for the superior articulating facet of S1.

A

B

FIGURE 3-390  Another example of an unfused ossification center for the superior facet of S1, not to be mistaken for a fracture. A, AP projection. B, Right oblique projection.

FIGURE 3-391  Marked lumbar lordosis may simulate the “Napoleon’s hat sign” of spondylolisthesis of L5 in the frontal projection.

The Spine  |  THE SACRUM

239

PART 1  |  CHAPTER 3



FIGURE 3-392  The alae of the sacral vertebrae in a 15-year-old boy.

FIGURE 3-394  The same phenomenon as seen in Figure 3-393, persisting in a 9-year-old boy.

FIGURE 3-396  “Angel-wing” sacrum, produced by ossification of the iliosacral ligaments.

FIGURE 3-393  The synchondrosis between the body and alae of the sacrum in a 3-year-old child. Such synchondroses usually close between ages 1 and 7 years.

FIGURE 3-395  Accessory ossification centers for the sacral alae in a 15-year-old boy.

FIGURE 3-397  Ossification of the iliosacral ligament (m). Note simulation of a destructive lesion in the sacrum immediately below, produced by overlying colonic gas (m 66).

240

The Spine  |  THE SACRUM

FIGURE 3-398  Developmental absence of a portion of the right ala of S1.

FIGURE 3-399  notochord.

Midline cleft of S1, probably related to persistence of the

FIGURE 3-400  Failure of fusion of the lateral elements of the sacrum producing “accessory sacroiliac joints.” FIGURE 3-401  The same entity as in Figure 3-400 seen unilaterally.

The Spine  |  THE SACRUM

241

PART 1  |  CHAPTER 3



FIGURE 3-402  Nutrient foramina of the sacral alae in an 8-year-old boy.

A

B

FIGURE 3-403  Normal variations in the appearance of the first sacral segment. A, Normal relative increase in density in a 2-year-old boy. This is at times mistaken for osteosclerosis. B, Pseudocyst of the sacrum (m) in a young adult as a result of the large amount of cancellous bone, with the suggestion of a similar appearance in the second sacral segment.

FIGURE 3-404  Simulated fracture of the sacrum in a young child. This appearance of the second and third sacral segments is not unusual in children.

242

A

The Spine  |  THE SACRUM

B FIGURE 3-405  A, Simulated fracture of the sacrum secondary to rotation. B, True lateral projection shows normal alignment.

FIGURE 3-406  Widening of the posterior aspect of the S1–S2 interspace, a variation in development in youth that may be mistaken for a destructive lesion. (Ref: Cacciarelli AA: Posterior widening of the S1–S2 interspace in children: A normal variant of sacral development. AJR Am J Roentgenol 129:305, 1977.)

FIGURE 3-407  Left, The wide posterior aspect of the S1–S2 interspace misdiagnosed as a fracture in a 13-year-old boy. Right, Follow-up film made 3 months later shows no change.

The Spine  |  THE SACRUM

243

PART 1  |  CHAPTER 3



FIGURE 3-408  Apparent lytic lesions of the sacrum produced by the shadows of the fossae cribrosa of the sacrum. (Ref: Kreyenbuhl W, Hessler C: A variation of the sacrum on the lateral view. Radiology 109:49, 1973.)

FIGURE 3-409  An additional example of simulated sacral lesions like that shown in Figure 3-408.

244

The Spine  |  THE SACRUM

A

B

FIGURE 3-410  A, Simulated destructive lesion of the sacrum produced by the fossae cribrosa and rotation. B, True lateral projection shows no abnormality.

A

B

FIGURE 3-411  A, Apparent fracture of the sacrum caused by rotation at the time of filming. B, Repeat film shows no abnormality.

The Spine  |  THE SACRUM

245

PART 1  |  CHAPTER 3



FIGURE 3-412  A, Unusually deep sacral curve resulting in apparent expansile lesions with shell-like margins. CT scans showed no intrinsic lesion of the sacrum.

A

B

C FIGURE 3-413  Unilateral (A) and bilateral (B) sacral ribs (m). C, Bilateral and asymmetric sacral ribs. Note also ossification of the iliolumbar ligaments and ilial spur at the right sacroiliac joint (m 66). (Ref: Halloran W: Sacral ribs. Q Bull Northwest Univ Med School 34:304, 1960.)

FIGURE 3-414  Sacral ribs on CT scan.

A

B

C FIGURE 3-415  Sacral rib. A, Plain film. B, Coronal CT section. C, Sagittal section.

The Spine  |  THE SACRUM

247

PART 1  |  CHAPTER 3



FIGURE 3-416  Unilateral sacral rib also seen in lateral projection.

FIGURE 3-418  Developmental defects in the ala of the sacrum.

FIGURE 3-417  Normal foraminal shadows in the sacrum.

FIGURE 3-419  Simulated destructive lesions of the wings of the sacrum produced by the foramina of the sacrum. Bowel gas may accentuate this appearance as well. A, Plain film. B, Tomogram.

A

B

248

The Spine  |  THE SACRUM

A

B

FIGURE 3-420  Simulated destructive lesion of the sacrum resulting from spina bifida occulta of S1. A, Lateral projection. B, CT scan.

FIGURE 3-421  Two examples of fossae in the sacral wings simulating destructive lesions.

The Spine  |  THE SACRUM

249

PART 1  |  CHAPTER 3



FIGURE 3-422  Developmental variations in the sacrum. Top left, Symmetric defects (m). Top right, Asymmetric defects (m). Calcification is present in the sacrospinal ligaments (m 6). Lower left and right, Other asymmetric defects.

FIGURE 3-423  Open sacral canal.

FIGURE 3-424  Fusion lines of the sacral segments simulating fractures.

250

The Spine  |  THE COCCYX

THE COCCYX

FIGURE 3-425  Normal anterior angulation of the coccyx. The position of the coccyx is not useful, in itself, in the identification of trauma. (Ref: Postacchini F, Massobrio M: Idiopathic coccygodynia: Analysis of fifty-one operative cases and a radiographic study of the normal coccyx. J Bone Joint Surg Am 65:1116, 1983.)

FIGURE 3-426  Anterior angulation of the coccyx. Note portions of the posterior arch of the distal portion of the sacrum, which might be mistaken for a fracture (m).

The Spine  |  THE COCCYX

251

PART 1  |  CHAPTER 3



FIGURE 3-427  Posterior position of the coccyx with reference to the distal end of the sacrum is a normal variation and not indicative of dislocation.

FIGURE 3-428  Marked anteflexion of the coccyx.

FIGURE 3-429  The junction of the coccyx and the last sacral segment, which can be mistaken for a fracture. FIGURE 3-430  “Floating coccyx.”

252

The Spine  |  THE COCCYX

FIGURE 3-431  The ossification center for the first coccygeal segment in a 10-year-old child, which should not be confused with a calculus or enterolith.

FIGURE 3-432  Axial view of the coccyx, which may simulate a calculus.

FIGURE 3-434  Congenital absence of the coccyx and anomalous development of the distal end of the sacrum. FIGURE 3-433  Congenital bifid coccyx.

FIGURE 3-435  Scoliosis of the coccyx.

The Spine  |  THE SACROILIAC JOINTS

253

THE SACROILIAC JOINTS

B

A

FIGURE 3-436  The sacroiliac joints in the adolescent are normally wide and irregular. These normal alterations should not be confused with the findings of sacroiliitis. A, Standard anteroposterior view of pelvis. B, Sacroiliac projection with 30-degree cephalad angulation of the tube (Ferguson’s projection).

FIGURE 3-437  Normal sclerosis and irregularity of the sacroiliac joints in a 14-year-old boy, resembling the changes of ankylosing spondylitis.

A

B

FIGURE 3-438  A, Simulated obliteration of the sacroiliac joints suggesting ankylosing spondylitis. B, Normal appearance of sacroiliac joints on Ferguson’s view. The frontal view of the pelvis cannot always be relied on to depict the true state of the sacroiliac joints.

PART 1  |  CHAPTER 3



254

The Spine  |  THE SACROILIAC JOINTS

B

A

FIGURE 3-439  A, Erroneous diagnosis of ankylosing spondylitis based on appearance of the sacroiliac joints. B, Ferguson’s view shows no abnormality.

A

B

FIGURE 3-440  A, Simulated obliteration of the sacroiliac joint caused by slight rotation. This appearance can be clarified by oblique projection of the sacroiliac joint (B).

FIGURE 3-441  Left, Apparent absence of the left sacroiliac joint caused by different plane of orientation of the joint compared with the right side. Right, Oblique projection shows an intact left sacroiliac joint.

The Spine  |  THE SACROILIAC JOINTS

255

PART 1  |  CHAPTER 3



FIGURE 3-442  Two examples of bilateral accessory sacroiliac joints. (Ref: Ehara S, et al: The accessory sacroiliac joint: A common anatomic variant. AJR Am J Roentgenol 150:857, 1988.)

FIGURE 3-443  Unilateral accessory sacroiliac joints that might be mistaken for fractures.

FIGURE 3-444  Striking example of secondary sacroiliac joints.

FIGURE 3-445  Vacuum phenomena in the sacroiliac joints.

256

The Spine  |  THE SACROILIAC JOINTS

FIGURE 3-446  Variations in development of the sacroiliac joints (top). CT scans illustrate the normal asymmetries to better advantage (center and bottom).

CHAPTER

3

The Spine

FIGURES

THE CERVICAL SPINE

3S-1 to 3S-87

THE THORACIC SPINE

3S-88 to 3S-107

THE LUMBAR SPINE

3S-108 to 3S-131

THE SACRUM

3S-132 to 3S-142

THE COCCYX

3S-143

THE SACROILIAC JOINTS

3S-144 to 3S-147

THE CERVICAL SPINE

FIGURE 3S-1  Apparent enlargement of the cervical spinal canal in a neonate as a result of flexion of the head at the time of filming and lordotic projection.

3S-62



The Spine  |  THE CERVICAL SPINE 3S-63

FIGURE 3S-2  Large cervical canal in a healthy 4½-year-old girl.

FIGURE 3S-3  Left, Simulated craniovertebral dislocation resulting from a slight tilting of the head at the time of filming. Right, Tomogram shows normal relationships of C1 to base of skull.

3S-64 The Spine  |  THE CERVICAL SPINE

FIGURE 3S-4  Partial assimilation of the left lateral mass of C1 at the base of the skull. Note the asymmetry of the lateral masses of C1 that accompanies this variation.

FIGURE 3S-6  Complete absence of the posterior neural arch of C1.  (Ref: Dalinka MK, et al: Congenital absence of the posterior arch of the atlas. Radiology 103:581, 1972.) FIGURE 3S-5  A second example of anomalous articulation between the posterior arch of C1 and the base of the skull.



The Spine  |  THE CERVICAL SPINE 3S-65

A

B

FIGURE 3S-7  Incomplete formation of the neural arch of C1 with fragment seen in lateral projection (A) and in Towne’s projection (B).

FIGURE 3S-9  Failure of fusion of the posterior portion of the neural arch of C1 in an 8-year-old boy.

FIGURE 3S-8  Unilateral incomplete neural arch of C1.

3S-66 The Spine  |  THE CERVICAL SPINE

FIGURE 3S-10  Incomplete development of the neural arch of C1 simulating a fracture. Proven by CT scanning.

A

B

C

FIGURE 3S-11  Unilateral absence of a portion of the neural arch of C1. A, Defect seen in lateral projection. B, Defect seen in oblique projection. C, Normal side for comparison. (Ref: Karasick S, Karasick D, Wechsler RJ: Unilateral spondylolysis of the cervical spine. Skeletal Radiol 9:259, 1983.)



The Spine  |  THE CERVICAL SPINE 3S-67

FIGURE 3S-12  The posterior arches of C1 (m) and C2 (m 6 ) seen in the steep Towne’s projection.

A

B FIGURE 3S-13  Simulated fracture probably resulting from calcification of anterior spinal ligament. A, Plain film. B, CT scan.

3S-68 The Spine  |  THE CERVICAL SPINE

FIGURE 3S-14  Fused ossicle above the anterior arch of C1.

FIGURE 3S-15  Huge ossicle fused to the anterior arch of C1.

FIGURE 3S-16  Probable calcification in the anterior longitudinal ligament below the anterior arch of C1.

A

B FIGURE 3S-17  A, Plain Film. B, CT Scan. Hemangioma of the left lateral mass of C1 producing unusual osseous pattern. Proven by MRI.



The Spine  |  THE CERVICAL SPINE 3S-69

B

A

FIGURE 3S-18  A, Plain Film. Shadow of the airway simulating a fracture of the lateral mass C1. B, Tomogram shows no fracture.

A

B FIGURE 3S-19  A, B, Two examples of normal asymmetry of the lateral masses of C2.

FIGURE 3S-20  Accessory ossicle at the tip of the odontoid on CT scan.

3S-70 The Spine  |  THE CERVICAL SPINE

FIGURE 3S-21  Persistence of a portion of the odontoid synchondrosis in a 13-year-old boy.

FIGURE 3S-22  “Double odontoid” produced by superimposition of the neural arch of C2.

FIGURE 3S-23  Failure of union of the odontoid process with a separate os odontoideum. Note also the failure of segmentation of C2. Os odontoideum is often difficult to differentiate from an old odontoid fracture. It is potentially dangerous if excessive motion is present. (Refs: Roback DL: Neck pain, headache, and loss of equilibrium after athletic injury in a 15-year-old boy. JAMA 245:963, 1981; Dawson LG, Smith L: Atlantoaxial subluxation in children due to vertebral anomalies. J Bone Joint Surg Am 61:582, 1979.)



The Spine  |  THE CERVICAL SPINE 3S-71

FIGURE 3S-24  Huge os odontoideum. Note also the hypertrophy of the anterior arch of C1.

FIGURE 3S-25  Hypoplastic odontoid (m). There is a spina bifida occulta of C2 and C3 producing an apparent cleft in the odontoid process (m 6).

FIGURE 3S-26  Asymmetric development of the lateral masses of C2 with lateral deviation of the odontoid process.

3S-72 The Spine  |  THE CERVICAL SPINE

A

B FIGURE 3S-27  A, B, Two examples of asymmetry of the lateral masses of C1 and C2.

A

B

FIGURE 3S-28  Unusual pointed anterior aspect of the odontoid process, not to be confused with the product of bony erosion (m). A, Plain film. B, Tomogram. Note also the spurlike extension from the superior aspect of the anterior arch of C1 (m66).



The Spine  |  THE CERVICAL SPINE 3S-73

FIGURE 3S-29  Marked “waist” in the midodontoid process.

FIGURE 3S-31  Pseudofracture of the body of C2 produced by overlapping shadows of the teeth.

FIGURE 3S-33  Pseudofracture of the odontoid process produced by overlapping of the base of skull.

FIGURE 3S-30  Rotation of the head producing an unusual elongated appearance of the lateral mass of C2.

FIGURE 3S-32  Pseudofracture of the base of the odontoid process produced by the Mach effect from overlapping shadows of the posterior arch of C1, the tongue, or the occiput. This was proven a pseudofracture by tomography. (Ref: Daffner RH: Pseudofracture of the dens: Mach bands. AJR Am J Roentgenol 128:607, 1977.)

3S-74 The Spine  |  THE CERVICAL SPINE

A

B

FIGURE 3S-34  A, Pseudofractures of the transverse processes of C1 and C2, produced by Mach bands, probably overlapping the shadow of the anterior tonsillar pillar. B, Tomography shows no evidence of a fracture.

FIGURE 3S-36  Unfused anterior neural arch of C1 on CT scan.

FIGURE 3S-35  Osseous density representing the lateral mass of C2, thrown into relief by rotation and tilting of the head.



The Spine  |  THE CERVICAL SPINE 3S-75

FIGURE 3S-37  Persistent apophysis for the transverse process of C2. (Ref: Kohler A, Zimmer EA: Borderlands of Normal and Early Pathologic Findings in Skeletal Radiography, 4th ed. New York: Thieme, 1993.)

A

B

FIGURE 3S-38  A, Simulated fracture or spondylolysis of C3 in infant as a result of positioning. B, Normal appearance seen on second exposure.

FIGURE 3S-39  Normal contour alterations in the neural arch of C2 can produce pseudofractures.

3S-76 The Spine  |  THE CERVICAL SPINE

FIGURE 3S-40  Additional example of the groove of the neural arch of C2 that can be mistaken for a fracture.

FIGURE 3S-41  Spondylolysis of C2 in a 2-month-old child. Note that spondylolisthesis may occur with this entity and does not necessarily denote prior trauma.



The Spine  |  THE CERVICAL SPINE 3S-77

B

A FIGURE 3S-42  A, Facet between C1 and C2 seen as osseous mass as the result of rotation. B, Frontal view shows no abnormality.

A

B

FIGURE 3S-43  A, Simulated lesions between C1 and C2 and between C2 and C3 produced by rotation. B, Improved positioning eliminates the shadows.

3S-78 The Spine  |  THE CERVICAL SPINE

FIGURE 3S-44  Left, Simulated fracture of the neural arch of C2, produced by rotation. Right, CT scan shows no fracture.

A

B

FIGURE 3S-45  A, Simulated fracture produced by Mach effect of the odontoid process (m). B, Tomogram shows no fracture of C1. Note the pseudofracture of C2 (m 6 ).



The Spine  |  THE CERVICAL SPINE 3S-79

FIGURE 3S-47  Developmental cleft in the anterior aspect of C2.

FIGURE 3S-46  Asymmetric appearance of the pedicles of C2 related to a larger left vertebral artery that demonstrates a mildly anomalous course (m). (Courtesy Dr. Victor Pullicino.)

FIGURE 3S-48  Failure of segmentation of the neural arches of C2 and C3.

FIGURE 3S-49  Partial nonsegmentation of C3 and C4.

3S-80 The Spine  |  THE CERVICAL SPINE

A

B FIGURE 3S-50  A, Posterior physiologic subluxation of C2 on extension view. B, Flexion view.

A

B

C

FIGURE 3S-51  Physiologic subluxation may occasionally be seen in cervical extension and in flexion, as in this 20-year-old man. A, Neutral position. B, Flexion. C, Extension. (Ref: Harris JH: Radiographically subtle soft tissue injuries of the cervical spine. Curr Probl Diagn Radiol 18:161, 1989.)



The Spine  |  THE CERVICAL SPINE 3S-81

A

B

FIGURE 3S-52  Normal cervical spine. A, Neutral position. B, Flexion. Note the striking alteration in curvature that can be produced with only slight alteration in head position.

FIGURE 3S-53  Physiologic subluxation of C2 on C3 and C3 on C4 on flexion in a 17-year-old boy.

3S-82 The Spine  |  THE CERVICAL SPINE

A

B FIGURE 3S-54  Physiologic subluxation of C2 on C3 and C3 on C4 in a 29-year-old pregnant woman, possibly related to relaxing hormone. A, Neutral position. B, Flexion.



The Spine  |  THE CERVICAL SPINE 3S-83

B

A

FIGURE 3S-55  A, Simulated fracture of the posterior neural arch of C3 produced by rotation. B, Corrected position. No fracture is seen.

A

B

FIGURE 3S-56  A, Pseudofracture of the neural arch of the type shown in Figure 3S-55 (m). B, Repeat film shows disappearance of the pseudofracture shown in A.

3S-84 The Spine  |  THE CERVICAL SPINE

A

B

FIGURE 3S-57  Accessory ossification centers at the tip of the spinous process of C3. A, Lateral projection. B, Oblique projection.

FIGURE 3S-58  Notochordal remnants at C2-C6.



The Spine  |  THE CERVICAL SPINE 3S-85

FIGURE 3S-59  Two examples of the pseudovacuum of the cervical intervertebral disc related to the Mach effect phenomenon. This appearance should not be confused with the true vacuum sign of an intervertebral disc injury. (Ref: Daffner RH, Gehweiler JA: Pseudovacuum of the cervical intervertebral disc: A normal variant. AJR Am J Roentgenol 137:737, 1981.)

FIGURE 3S-60  Two examples of simulated fusion of the apophyseal joints produced by projection.

3S-86 The Spine  |  THE CERVICAL SPINE

FIGURE 3S-61  Normal retention of wedge configuration of C3, C4, and C5 in an adult.

FIGURE 3S-62  Bifid spinous process of C4 with failure of union of the right limb.



The Spine  |  THE CERVICAL SPINE 3S-87

FIGURE 3S-63  Unusual contour defect along the anterior margin of the vertebral end plate.

A

B FIGURE 3S-64  A, B, Contour defects at C6 similar to those in Figure 3S-63.

3S-88 The Spine  |  THE CERVICAL SPINE

FIGURE 3S-65  Simulated destructive lesion of the third and fourth cervical vertebrae produced by slight rotation at the time of filming.

FIGURE 3S-66  Unfused uncinate apophysis, which might be mistaken for a fracture. (Ref: Schaaf RE, et al: Lateral hyperflexion injuries of the cervical spine. Skeletal Radiol 3:73, 1978.)

FIGURE 3S-67  Un-united ossification center of the inferior articular process of C5.



The Spine  |  THE CERVICAL SPINE 3S-89

FIGURE 3S-68  Un-united ossification centers of the transverse processes of the last two cervical vertebrae in a 38-year-old man.

A

B

FIGURE 3S-69  A, Facet seen in the oblique projection and mistaken for a fracture of the pedicle. B, Tomogram shows no fracture. (Ref: Zielinski CJ, Griffith JL: A joint shadow in the cervical spine presenting as a vertebral body fracture: A case report. Spine 12:595, 1987.)

3S-90 The Spine  |  THE CERVICAL SPINE

FIGURE 3S-70  A facet resembling a fracture, seen in the oblique projection.

A

B

FIGURE 3S-71  A, Simulated fractures of the laminae of C5, produced by facets. B, Tomogram shows no fracture.



The Spine  |  THE CERVICAL SPINE 3S-91

FIGURE 3S-72  Two examples of a simulated facet fracture at C5 produced by rotation of the spine at the time of filming.

FIGURE 3S-73  An anomalous articulation between the transverse processes of C5 and C6 can be seen with incomplete segmentation of these two vertebral bodies.

3S-92 The Spine  |  THE CERVICAL SPINE

FIGURE 3S-74  Uptilted spinous process of C5 might be misconstrued as evidence of soft tissue injury between C5 and C6.

FIGURE 3S-75  Marked variability in the size of the cervical vertebrae.



The Spine  |  THE CERVICAL SPINE 3S-93

FIGURE 3S-76  Sclerosis of the pedicles and posterolateral aspects of the vertebral bodies in a 36-year-old woman. This finding is apparently not related to degenerative spondylosis.

3S-94 The Spine  |  THE CERVICAL SPINE

FIGURE 3S-77  Ossicle between C5 and C6, probably ligamentous.

FIGURE 3S-78  Calcification of the ligamentum nuchae at the base of the skull.

FIGURE 3S-79  Large transverse processes with attempts to form ribs at C5 and C7.

FIGURE 3S-80  Left, Long transverse process of C6, simulating a fracture. Right, Oblique projection shows the elongated transverse process.



The Spine  |  THE CERVICAL SPINE 3S-95

FIGURE 3S-81  Left, Ringlike shadow produced by lateral elements of the vertebra with slight rotation at the time of filming. Right, True lateral projection does not show the ring shadow.

FIGURE 3S-82  Partial segmentation error at C4-C5. Note the underdevelopment of the vertebral bodies.

3S-96 The Spine  |  THE CERVICAL SPINE

FIGURE 3S-84  Posterior tilt of the spinolaminar line of C6, which should not be confused with the effect of an intraspinal lesion. FIGURE 3S-83  Failure of segmentation of C5-C6.

FIGURE 3S-85  Left, The laminar notch at C7, which was mistaken for a fracture. Right, Tomogram shows no fracture.



The Spine  |  THE CERVICAL SPINE 3S-97

FIGURE 3S-86  Top left, The lateral elements of C6 projected slightly caudad show two apophyseal joints that were misinterpreted as fractures. Top right and bottom, Oblique projections show no abnormality.

3S-98 The Spine  |  THE THORACIC SPINE

FIGURE 3S-87  Left, Partial nonsegmentation of C6 and C7, which was mistaken for acquired narrowing of the intervertebral disc in a 35-year-old man. C2 and C3 are also nonsegmented. Right, The spina bifida occulta at C6 indicates the developmental nature of the finding at C6 and C7.

THE THORACIC SPINE

FIGURE 3S-88  Left, Residual venous sinus grooves may add to the impression of a compression fracture in a poorly positioned lateral projection. Right, Better lateral projection shows no fracture.



The Spine  |  THE THORACIC SPINE 3S-99

FIGURE 3S-90  Ossification centers at the distal ends of the transverse processes of T1 in an adolescent. FIGURE 3S-89  Persistence of the posterior vascular notch in a 33-year-old man.

FIGURE 3S-91  Unfused ossification centers of the transverse processes of T1.

FIGURE 3S-92  Two examples of how the lateral elements of T1 produce apparent sclerosis of a portion of the vertebral body and may simulate a metastatic deposit.

3S-100 The Spine  |  THE THORACIC SPINE

FIGURE 3S-94  Shadow produced by the normal posterior angulation of the transverse process of T1.

FIGURE 3S-93  Ringlike shadow produced by the lateral elements of the vertebra with slight rotation.

FIGURE 3S-96  Magnification of the upper thoracic vertebra caused by kyphosis.

FIGURE 3S-95  Pedicle thinning at the thoracolumbar junction may be extreme and may even be associated with concave medial borders. The absence of pertinent clinical findings should suggest this recognized normal variation. (Ref: Charlton OP, et al: Pedicle thinning at the thoracolumbar junction: A normal variant. AJR Am J Roentgenol 134:825, 1980.)



The Spine  |  THE THORACIC SPINE 3S-101

FIGURE 3S-98  Spina bifida of the spinous process of T12. FIGURE 3S-97  Spina bifida occulta and segmentation anomalies of the upper thoracic spine.

FIGURE 3S-100  Spina bifida occulta of T11 and T12, and L1 and L2.

FIGURE 3S-99  Thoracic lordosis, a normal variation, in a 54-year-old man.

3S-102 The Spine  |  THE THORACIC SPINE

FIGURE 3S-101  Spina bifida occulta of T12.

FIGURE 3S-102  Two examples of how the facet joints of the spine may simulate bulging annuli or paraspinous masses.



The Spine  |  THE THORACIC SPINE 3S-103

FIGURE 3S-104  Simulated nodule produced by slight thickening of the bone at the superior aspect of the area where the two laminae join to form the spinous process. (Ref: Shortsleeve MJ, Foster SC: Pulmonary nodule. Radiology 131:311, 1979.)

FIGURE 3S-103  “Bumpy spine” produced by hypertrophy of the costovertebral articulations.

FIGURE 3S-105  Atypical jointlike union of the transverse processes at the level of T4 and T5.

3S-104 The Spine  |  THE LUMBAR SPINE

FIGURE 3S-107  The costovertebral articulation superimposed on the body of T12.

FIGURE 3S-106  Anomalous articulation between the rib and the adjacent transverse process.

THE LUMBAR SPINE

A

B

FIGURE 3S-108  Two examples of “growth lines” in the lumbar vertebra. A, A 19-year-old man. B, A 38-year-old man.



The Spine  |  THE LUMBAR SPINE 3S-105

FIGURE 3S-109  Normal variation in pedicle size. The interpediculate distance in this variation does not exceed two standard deviations from the mean. (Ref: Benzian SR, et al: Pediculate thinning: A normal variant of the thoracolumbar junction. Br J Radiol 44:936, 1971.)

A

B

FIGURE 3S-110  Two examples of end-plate depressions secondary to notochordal remnants. Indentations of this type in the end plates of normal vertebrae of young people indicate the site of the notochordal recession into the intervertebral disc. They should be differentiated from Schmorl’s nodes. A, A 27-year-old man. B, A 12-year-old girl. (Ref: Dietz GW, Christensen EE: Normal “Cupid’s bow” contour of the lower lumbar vertebrae. Radiology 121:577, 1976.)

3S-106 The Spine  |  THE LUMBAR SPINE

FIGURE 3S-111  Unusually tall intervertebral discs in a 31-year-old woman.

FIGURE 3S-112  Hypoplastic vertebra on the left, originally misinterpreted as a lytic lesion of the vertebra. Note that in the frontal plane, vertebral end plates are seen only on the right side.



The Spine  |  THE LUMBAR SPINE 3S-107

FIGURE 3S-113  Failure of union of the L1 transverse process with the vertebral body.

FIGURE 3S-114  Very large anomalous articulation between the transverse processes of L3 and L4. Left, AP projection. Center, Lateral projection. Right, Oblique projection.

3S-108 The Spine  |  THE LUMBAR SPINE

FIGURE 3S-116  Persistence of the apophysis of the transverse process of L5.

FIGURE 3S-115  Abortive rib formation at L2.

FIGURE 3S-117  Separate ossification center for the transverse process of L5.

FIGURE 3S-118  Failure of fusion of the ossification center of the superior articulating process of L4.



The Spine  |  THE LUMBAR SPINE 3S-109

FIGURE 3S-119  The facets between L4 and L5, simulating an osseous or soft tissue mass.

A

B

C

D

FIGURE 3S-120  A, B, Apparent bilateral spondylolysis of L5 caused by projection. C, D, Films made with 15-degree cephalad angulation show no spondylolysis.

3S-110 The Spine  |  THE LUMBAR SPINE

A

C

B FIGURE 3S-121  A, Lucency in the neural arch of L4 simulating a fracture. B, Cleft in the superior facet of L4 associated with spondylosis of L5 on the right (C).



The Spine  |  THE LUMBAR SPINE 3S-111

A

C

B

D

FIGURE 3S-122  Congenital absence of the pedicle on the right side of L4 with incomplete segmentation of L3 and L4. A, B, Plain films. C, D, Tomograms. Note the huge intervertebral foramen in D. (Ref: MacLeod S, Hendry GMA: Congenital absence of a lumbar pedicle: A case report and a review of the literature. Pediatr Radiol 12:207, 1982.)

3S-112 The Spine  |  THE LUMBAR SPINE

A

B

C

D

FIGURE 3S-123  Absence of the lamina of L5 on the left. A, AP projection. B, Lateral projection. C, Right posterior oblique projection. D, Left posterior oblique projection.



The Spine  |  THE LUMBAR SPINE 3S-113

FIGURE 3S-124  The closing apophyses of the spinous processes of the lumbar spine in a 22-year-old man.

A

B

FIGURE 3S-125  Sclerosis of the spinous process of L4 as an incidental finding. A, AP projection. B, Lateral projection.

3S-114 The Spine  |  THE LUMBAR SPINE

FIGURE 3S-126  Un-united apophysis of the spinous process of L1.

A

B FIGURE 3S-127  A, B, Two examples of failure of union of the ossification centers of the tip of the L5 spinous process.



The Spine  |  THE LUMBAR SPINE 3S-115

FIGURE 3S-128  Simulated defect produced by the neural arch of L5. A CT scan showed a herniated nucleus but no defect in the vertebral body.

FIGURE 3S-129  Spina bifida occulta of L5, off center, which might be confused with a fracture.

FIGURE 3S-130  Partial formation of an anomalous articulation of L5 with the sacrum.

3S-116 The Spine  |  THE SACRUM

FIGURE 3S-131  Conjoined lumbosacral nerve roots may be mistaken for the impressions of a disc herniation. Two root sleeves are demonstrated by myelography. (Ref: Cail WS, Butler AB: Conjoined lumbosacral nerve roots: Diagnosis with metrizamide myelography. Surg Neurol 20:113, 1983.)

THE SACRUM

FIGURE 3S-132  Un-united ossification center for the spinous process of S1.

FIGURE 3S-133  Un-united ossification center for the spinous process of S1 associated with spina bifida occulta.



The Spine  |  THE SACRUM 3S-117

FIGURE 3S-134  Calcification of the iliosacral ligaments. FIGURE 3S-135  Lumbarized S1 with residual disc (m).

FIGURE 3S-136  Unilateral anomalous articulation between S1 and S2.

FIGURE 3S-137  The S1–S2 posterior widening in a 15-year-old boy. At this age, the end plates are better defined.

3S-118 The Spine  |  THE SACRUM

FIGURE 3S-138  Lucency in posterior aspect of S1 in a 16-year-old boy simulating a destructive lesion.



The Spine  |  THE SACRUM 3S-119

A

B

C FIGURE 3S-139  Simulated destructive lesion of the sacrum produced by the posterior elements. A, Simulated lesion in lateral projection. B, Midline tomogram shows no abnormality. C, Simulated lesion is seen in a parasagittal tomographic section.

3S-120 The Spine  |  THE SACRUM

A

B

FIGURE 3S-140  A, Simulated destructive lesion of S1 caused by rotation at time of filming. B, Tomogram shows no abnormality.

FIGURE 3S-141  Large posterior elements of the fourth and fifth sacral segments.

FIGURE 3S-142  Scoliosis of the sacrum and coccyx.



The Spine  |  THE SACROILIAC JOINTS 3S-121

THE COCCYX

FIGURE 3S-143  The ischial apophysis in a 15-year-old boy, not to be confused with a fracture of the tip of the coccyx.

THE SACROILIAC JOINTS

FIGURE 3S-144  Three examples of secondary ossification centers of the wings of the sacrum. (Ref: Funke M, et al: The apophyses of the sacroiliac joints. Fortsch Roentgenstr 157:43, 1992.)

3S-122 The Spine  |  THE SACROILIAC JOINTS

FIGURE 3S-146  Secondary sacroiliac joint on the right. Note the unusual clarity of the right sacroiliac joint compared with the left.

FIGURE 3S-145  Persistence of a secondary center of ossification of the sacrum in a 25-year-old woman.

FIGURE 3S-147 Obliteration of the sacroiliac joints in a 73-year-old man. This phenomenon may apparently occur in the absence of inflammatory spondylitis. (Ref: Resnick D, et al: Clinical and radiographic abnormalities in ankylosing spondylitis: A comparison of men and women. Radiology 119:293, 1976.)

CHAPTER

4

The Pelvic Girdle PAGES

FIGURES

257 to 264

THE ILIUM

4-1 to 4-24

265 to 275

THE PUBIS AND ISCHIUM

4-25 to 4-61

275 to 284

THE ACETABULUM

4-62 to 4-100

THE ILIUM

FIGURE 4-1  “Double” iliac wings produced by the shadow of the buttocks.

FIGURE 4-2  Example of the grooves for the nutrient arteries of the ilium.

257

The Pelvic Girdle  |  THE ILIUM

258

FIGURE 4-3  Pneumocyst of the left ilium on CT scan in an 18-year-old woman, an incidental finding. (Ref: Hall FM, Turkel D: Case report 526: Intraosseous pneumocyst of the ilium. Skeletal Radiol 18:127, 1989; Hertzanu Y, Bar-Ziv J: Case report 606: Gas-filled subchondral cyst of ilium secondary to osteoarthritis of the sacroiliac joint. Skeletal Radiol 19:225, 1990.)

FIGURE 4-4  Normal lucency of the iliac fossae, which may resemble lytic lesions in bone.

FIGURE 4-5  Two examples of the preauricular sulcus (paraglenoid). This groove is caused by resorption of bone at the insertion of the anterior sacroiliac ligament in response to stress. It is characteristic of the female pelvis and is not necessarily symptomatic. Very deep sulci are found only in parous women. (Refs: Dee PM: The preauricular sulcus. Radiology 140:354, 1981; Schemmer D, et al: Radiology of the paraglenoid sulcus. Skeletal Radiol 24:205, 1995.)

A

B

FIGURE 4-6  A, Unusual preauricular sulcus with asymmetry with opposite side. B, Paraglenoidal sulci simulating destructive lesions on the Ferguson view.

The Pelvic Girdle  |  THE ILIUM

FIGURE 4-7  Foramina in the ilia of a 25-year-old man.

A

259

PART 1  |  CHAPTER 4



B

FIGURE 4-8  A, Crest between the insertions of the gluteus maximus and erector spinae muscles. B, CT scan showing the location of the crest.

B

A

FIGURE 4-9  A, Linear density in the ilium (A), seen on CT scans (B, C) as a spurlike ridge on the inner aspect of the iliac bone. This finding may represent the origin of the iliacus muscle. (Courtesy Dr. L.M. Boolkin.)

C

260

The Pelvic Girdle  |  THE ILIUM

FIGURE 4-10  Dense white lines probably representing the roofs of the sciatic foramina.

FIGURE 4-11  Irregular ossification of the ilium seen in adolescents, representing the origins of the sartorius muscle. These areas may mimic destructive lesions.

FIGURE 4-12  Spurring of muscle attachments at the ilium, seen in aged individuals.

The Pelvic Girdle  |  THE ILIUM

261

PART 1  |  CHAPTER 4



A

B FIGURE 4-13  Growing bone islands in a normal male. There is a 4-year interval between films shown in A and B. (Ref: Blank N, Lieber A: The significance of growing bone islands. Radiology 85:508, 1965.)

FIGURE 4-14  Giant bone island in a 60-year-old man. (Refs: Smith J: Giant bone islands. Radiology 107:35, 1973; Ehara S, et al: Giant bone island: Computed tomography findings. Clin Imaging 13:231, 1989.)

The Pelvic Girdle  |  THE ILIUM

262

A

B

FIGURE 4-15  Iliac bone island. These are common in the ilium, may grow, and occasionally disappear. They are of no clinical significance. A, Iliac bone island in a young woman. B, Nine years later, the bone island has enlarged. (Ref: Kim SK, Barry WF Jr: Bone islands. Radiology 90:77, 1968.)

FIGURE 4-16  A, B, Two examples of normal aging changes in the pelvic brim. This alteration in elderly patients may be mistaken for periostitis or Paget’s disease.

A

B

FIGURE 4-17  A, B, The development of pelvic “ears” is secondary to these long caudad extensions of the iliac apophyses seen in a 15-year-old boy.

A

B

The Pelvic Girdle  |  THE ILIUM

263

PART 1  |  CHAPTER 4



FIGURE 4-18  Partial closure of the apophyses illustrated in Figure 4-17 should not be mistaken for evidence of trauma.

A

B

FIGURE 4-19  A, Irregularity of the anterior inferior iliac spine in an adolescent boy. This represents a “tug” lesion at the insertion of the rectus femoris tendon and should not be mistaken for the changes of neoplasm. B, Enlargement of area of interest. Note that the muscle planes are not disturbed. (Ref: Murray RO, Jacobson HG: The Radiology of Skeletal Disorders, 2nd ed. London, Churchill Livingstone, 1977.)

FIGURE 4-20  Combined pelvic “ears” (m) and healed “avulsive” lesions (m 6) of the anterior inferior iliac spine in a 24-year-old man with pelvic fractures.

264

The Pelvic Girdle  |  THE ILIUM

FIGURE 4-21  Unusual accessory elements arising from the acetabular margins.

FIGURE 4-22  An iliac rib (pelvic digit), a developmental anomaly. Note pseudoarticulation. (Ref: Greenspan A, Norman A: The “pelvic digit”: An unusual developmental anomaly. Skeletal Radiol 9:118, 1982.)

FIGURE 4-23  Two additional examples of pelvic digits. (Ref: Granieri GF, Bacarini L: The pelvic digit: Five new examples of an unusual anomaly. Skeletal Radiol 25:723, 1996.)

FIGURE 4-24  Asymmetric closure of the synchondrosis between the ilium and ischium in an 8-year-old girl, which was misinterpreted as a fracture.

The Pelvic Girdle  |  THE PUBIS AND ISCHIUM

265

THE PUBIS AND ISCHIUM

A

B

FIGURE 4-25  Faulty positioning with rotation may simulate medial protrusion of the ischium and a fracture through the triradiate cartilage in a normal immature pelvis. A, An infant. B, An older child. (Ref: Shipley RT, et al: Artifact of projection simulating a pelvic fracture. AJR Am J Roentgenol 141:479, 1983.)

FIGURE 4-26  Duplicate ossification centers of the pubis in a 3-day-old child (see Figure 4-27).

FIGURE 4-27  Double ossification centers of the pubis in a 3-month-old child. This appearance should not be mistaken for evidence of child abuse. (Ref: Caffey J, Madell SH: Ossification of the pubic bones at birth. Radiology 67:346, 1956.)

FIGURE 4-28  Duplicate ossification center seen unilaterally.

PART 1  |  CHAPTER 4



The Pelvic Girdle  |  THE PUBIS AND ISCHIUM

266

A

B

FIGURE 4-29  Cephalad angulation of the beam may produce a double contour of the upper aspects of the superior pubic rami, which may be mistaken for periosteal proliferation. A, Marked cephalad angulation. B, Perpendicular projection shows only a single contour of the bone.

FIGURE 4-30  Simulated periosteal proliferation of the superior rami of the pubis in an 8-year-old caused by cephalad angulation of the beam.

The Pelvic Girdle  |  THE PUBIS AND ISCHIUM

267

PART 1  |  CHAPTER 4



FIGURE 4-31  Normal variations and asymmetry in closure of the ischiopubic synchondrosis. These are normal phenomena and should not be mistaken for evidence of osteochondrosis.

FIGURE 4-32  Delayed closure of the ischiopubic synchondroses in a healthy 15-year-old boy. These synchondroses usually close between 4 and 8 years of age.

268

The Pelvic Girdle  |  THE PUBIS AND ISCHIUM

A

B

FIGURE 4-33  Normal open ischiopubic synchondrosis in a 6-year-old boy thought to represent a destructive lesion. A, Plain film. B, Nuclear scan.

FIGURE 4-34  Incomplete development of the obturator rings in an otherwise healthy woman.

FIGURE 4-35  Incomplete closure of the ischiopubic synchondroses in a 72-year-old woman. Note accessory ossification centers in gaps. (Ref: Sandomenico C, Tamburrini O: Bilateral accessory ossification center of the ischiopubic synchondrosis in a female infant: Follow-up for over a three-year period. Pediatr Radiol 10:233, 1981.)

The Pelvic Girdle  |  THE PUBIS AND ISCHIUM

269

PART 1  |  CHAPTER 4



FIGURE 4-36  Failure of closure of the ischiopubic synchondroses in a healthy 21-year-old woman.

FIGURE 4-37  The normal ischial apophyses in a 20-year-old woman.

FIGURE 4-38  The ischial apophysis seen en face may simulate a fracture in adolescence.

270

The Pelvic Girdle  |  THE PUBIS AND ISCHIUM

FIGURE 4-39  The closed ischial apophysis.

FIGURE 4-40  An unusual presentation of the ischial apophysis in the lateral projection of the hip in a 13-year-old boy (left). AP view (right) shows only the margin of the apophysis.

FIGURE 4-41  Prominent ischial apophysis in an asymptomatic 12-year-old boy.

The Pelvic Girdle  |  THE PUBIS AND ISCHIUM

271

PART 1  |  CHAPTER 4



FIGURE 4-42  Normal irregularities of ossification of the ischia in adolescent children. These changes are usually asymmetric and disappear with age. They represent “tug” lesions caused by the pull of the hamstring muscles on the apophyses.

FIGURE 4-43  Fused ischial apophyses in a 26-year-old man.

FIGURE 4-44  Simulated destructive lesion in the ischium produced by the edge of the ischial tuberosity. The same phenomenon is present to a lesser degree on the opposite side.

272

A

The Pelvic Girdle  |  THE PUBIS AND ISCHIUM

B FIGURE 4-45  Accessory ossification centers at the symphysis pubis. A, A 19-year-old man. B, A 20-year-old man.

FIGURE 4-46  Normal irregular ridges on the medial aspects of the pubic bones in a 22-year-old man.

FIGURE 4-47  Simulated cysts of the symphysis pubis produced by areas of thin bone below the superior ramus of the pubis.

FIGURE 4-48  Developmental notches at the closed ischiopubic junctions.

The Pelvic Girdle  |  THE PUBIS AND ISCHIUM

273

PART 1  |  CHAPTER 4



FIGURE 4-49  Fossae in the inferior rami of the pubis.

FIGURE 4-50  Normal developmental irregularities of the symphysis pubis in an 18-year-old man.

FIGURE 4-51  Postpartum changes in the symphysis pubis.

A

B

FIGURE 4-52  A, B, Pubic spurs are a common normal variation in development. The malalignment of the symphysis in A is a postpartum alteration.

FIGURE 4-53  Ossification of the suprapubic ligament in a 42-year-old woman.

274

The Pelvic Girdle  |  THE PUBIS AND ISCHIUM

FIGURE 4-54  Ossification of the suprapubic ligament in a 74-year-old man.

FIGURE 4-56  Normal malalignment of the symphysis pubis in a 14-year-old girl. The lower margin of the symphysis is a more reliable indicator of alignment than the upper margin. (Ref: Vix VA, Ryu CY: The adult symphysis pubis: Normal and abnormal. Am J Roentgenol Radium Ther Nucl Med 112:517, 1971.) Note also the accessory ossification center in the margin of the left side of the symphysis. Such accessory centers are common in the juvenile symphysis.

FIGURE 4-55  Massive calcification of the suprapubic ligament in a 75-year-old man.

FIGURE 4-57  Congenitally wide symphysis pubis in a young man with no history of trauma or developmental defect. This is a rare isolated variant. (Ref: Muecke EC, Currarino G: Congenital widening of the pubic symphysis: Associated clinical disorders and roentgen anatomy of affected bony pelves. Am J Roentgenol Radium Ther Nucl Med 103:179, 1968.)

FIGURE 4-59  Discrete radiolucencies in the ischia produced in part by the crossing shadow of the pubis. Such radiolucencies are seen in children and adults.

FIGURE 4-58  Simulated cyst of the pubis resulting from spurs in the obturator foramen. Note spur on opposite side as well.

The Pelvic Girdle  |  THE ACETABULUM

275

PART 1  |  CHAPTER 4



FIGURE 4-60  Marked calcification in Cooper’s ligaments.

FIGURE 4-61  Rider’s bone ossification in an adductor muscle, which is seen most commonly in horseback riders.

THE ACETABULUM

FIGURE 4-62  Normal protrusio acetabuli (m) in a 7-year-old girl. This is a normal phenomenon seen in children from about 4 to 12 years of age. Note also the normal radiolucent patches above the acetabula (m 66). (Ref: Alexander C: The aetiology of primary protrusio acetabuli. Br J Radiol 38:567, 1965.) FIGURE 4-63  Mild protrusio acetabuli may be seen as a normal variation. The distance between the medially located acetabular line and the laterally located ilioischial line may be up to 6 mm in women and 3 mm or more in men. (Ref: Resnick D: Diagnosis of Bone and Joint Disorders, 3rd ed. Philadelphia, WB Saunders, 1995.)

276

The Pelvic Girdle  |  THE ACETABULUM

FIGURE 4-65  Chondroid stripes in the acetabula in a 12-year-old girl. This is a common finding in adolescents.

FIGURE 4-64  Normal irregularity of the acetabular roofs in a young child. This appearance is normal between ages 7 and 12 years.

FIGURE 4-66  Normal nutrient foramina, multiple on the right and single on the left.

FIGURE 4-67  Plain film showing pit for nutrient vessels in acetabulum (m). If completely superimposed on the femoral head, this shadow may simulate a destructive lesion (m 66).

FIGURE 4-69  Persistence of the os acetabuli marginalis superior on the right in a 40-year-old man. FIGURE 4-68  Accessory ossification centers in the superior portions of the acetabula (os acetabuli marginalis superior) in a 14-year-old boy (m). Note also additional ossification centers in the acetabula at lower levels (m 66). These centers usually fuse solidly with the contiguous portions of the ilium. (Ref: Silverman FN, Kuhn J: Caffey’s Pediatric X-Ray Diagnosis, 9th ed. St. Louis, Mosby, 1993.)

The Pelvic Girdle  |  THE ACETABULUM

277

PART 1  |  CHAPTER 4



FIGURE 4-70  Partial union of secondary ossification centers of the acetabula in the adolescent.

FIGURE 4-71  Additional example of multiple accessory ossification centers of the acetabula in a 14-year-old girl.

FIGURE 4-73  An os acetabuli marginalis superior persisting as a separate ossicle into adult life. Such a persistent ossification center is commonly called an “os acetabuli.”

FIGURE 4-72  Unusual appearance of the left femoral head in a 6-year-old girl resulting from irregular closure of secondary ossification centers of the acetabulum.

FIGURE 4-74  Bilateral os acetabuli marginalis superior in a 25-year-old man.

278

The Pelvic Girdle  |  THE ACETABULUM

A

B

FIGURE 4-75  A, Persistent os acetabuli marginalis superior misdiagnosed as a fracture. B, CT scan shows the ossicle of the anterior lip of the acetabulum.

A

B FIGURE 4-76  The os acetabuli on plain film (A) and CT scan (B).

FIGURE 4-78  Incomplete closure of the ossification centers of the acetabulum simulating fractures in a 40-year-old man.

FIGURE 4-77  Small os acetabuli.

The Pelvic Girdle  |  THE ACETABULUM

279

PART 1  |  CHAPTER 4



A

B

FIGURE 4-79  A, Another example of the accessory center of ossification of the posterior lip of the acetabulum simulating a fracture in a 32-year-old woman. B, A similar but less marked appearance is present in opposite hip.

FIGURE 4-80  The same entity as in the preceding two figures with CT confirmation.

FIGURE 4-81  Unilateral un-united apophysis on the left.

FIGURE 4-82  A large accessory bone at the posterior margin of the acetabulum.

280

The Pelvic Girdle  |  THE ACETABULUM

FIGURE 4-83  Huge traction spurs at the acetabular margins.

A

B

FIGURE 4-84  A, B, The lucent interval in two other patients produces an appearance simulating a fracture of the posterior wall of the acetabulum (see Figures 4–79 through 4–82.)

FIGURE 4-85  Apparent defects in the acetabulum as a result of projection and not anatomic alteration.

The Pelvic Girdle  |  THE ACETABULUM

281

PART 1  |  CHAPTER 4



FIGURE 4-86  Two other examples of fossae (different patients) that should not be mistaken for pathologic processes. Bilateral symmetry is helpful.

FIGURE 4-87  Exaggerated lucencies of the acetabula.

FIGURE 4-88  Bone island in the ischium simulating a foveal lesion.

282

The Pelvic Girdle  |  THE ACETABULUM

FIGURE 4-90  The roofs of the acetabula may project asymmetrically in normal individuals.

FIGURE 4-89  In the lateral projection of the hip, the superior margin of the acetabulum may simulate a cyst.

FIGURE 4-92  Marked notching of the superior acetabula.

FIGURE 4-91  The superior acetabular notch is the result of an accessory fossa in the apex of the acetabulum and is of no significance. (Ref: Johnstone WH, et al: The anatomic basis for the superior acetabular roof notch “Superior acetabular notch”. Skeletal Radiol 8:25, 1982.)

FIGURE 4-94  The supra-acetabular notch on CT scan.

FIGURE 4-93  Unusual second lateral notch in the roof of the acetabulum in a young woman. (Courtesy Dr. W.B. Guilford.)

The Pelvic Girdle  |  THE ACETABULUM

283

PART 1  |  CHAPTER 4



A

B FIGURE 4-95  The acetabular notches demonstrated by MRI. A, Plain film. B, T2-weighted MR image shows fluid signal in the notches as anticipated.

A

B FIGURE 4-96  A, B, Bilateral, laterally placed acetabular notches.

FIGURE 4-97  Exaggeration of the normal triangle of radiolucency above the acetabula. The slight difference in density is caused by rotation as evidenced by the asymmetry of the obturator foramina.

FIGURE 4-98  Normal triangular area of lucency above the right acetabulum (m). This is normally bilaterally symmetric. The greater radiolucency on the left is caused by metastatic neoplasm (m 6 ). Note lack of rotation at time of filming.

284

The Pelvic Girdle  |  THE ACETABULUM

FIGURE 4-99  Normal asymmetry in the density of the roofs of the acetabula in a 30-year-old man, not to be confused with the changes of degenerative arthritis. Note symmetry in width of the superior joint spaces.

FIGURE 4-100  Sclerosis of the inferior lips of the acetabula without degenerative joint disease.

CHAPTER

4

The Pelvic Girdle

FIGURES

THE ILIUM

4S-1 to 4S-18

THE PUBIS AND ISCHIUM

4S-19 to 4S-33

THE ACETABULUM

4S-34 to 4S-52

THE ILIUM

FIGURE 4S-1  Normal irregularity of the iliac crest in a 9-year-old boy. This appearance is typical before the development of the secondary ossification center for the crest of the ilium.

4S-123

4S-124 The Pelvic Girdle  |  The Ilium

FIGURE 4S-3  Unusual fossae in the ilia in a 37-year-old man.

FIGURE 4S-2  Example of the grooves for the nutrient arteries of the ilium.

FIGURE 4S-4  Examples of the preauricular sulcus (paraglenoid). This groove is due to resorption of bone at the insertion of the anterior sacroiliac ligament in response to stress. It is characteristic of the female pelvis and is not necessarily symptomatic. Very deep sulci are found only in parous women. (Refs: Dee PM: The preauricular sulcus. Radiology 140:354, 1981; Schemmer D, et al: Radiology of the paraglenoid sulcus. Skeletal Radiol 24:205, 1995.)



The Pelvic Girdle  |  The Ilium 4S-125

B

A

FIGURE 4S-5  Small notches in the ilia in males, similar to the paraglenoidal sulci. A, A 17-year-old boy. B, A 50-year-old man.

A

B

FIGURE 4S-6  Crest between the insertions of the gluteus maximus and erector spinae muscles seen bilaterally in A and unilaterally in B, the latter originally misinterpreted as a fracture.

4S-126 The Pelvic Girdle  |  The Ilium

FIGURE 4S-7  Developmental spurs at the inferior aspect of the sacroiliac joints. Top left, 30-year-old man. Top right, 30-year-old woman. Bottom, 55-year-old man.

FIGURE 4S-8  Irregularity of the ilium seen in adolescents may mimic destructive lesions.



The Pelvic Girdle  |  The Ilium 4S-127

A

B FIGURE 4S-9  A, Flanges on the edge of the ilium, which may simulate sclerotic lesions (B).

FIGURE 4S-10  Iliac bone islands. Bone island in a 27-year-old man (m). These are common in the ilium, may grow, and occasionally disappear. They are of no clinical significance. A ring lesion (herniation pit) is present in the left femoral neck (m 66).

4S-128 The Pelvic Girdle  |  The Ilium

FIGURE 4S-11  Ossification centers for the anterior inferior iliac spine (m) and acetabular rim (m 66) in a 13-year-old boy.

FIGURE 4S-12  Prominent anterior inferior iliac spines in a 12-year-old boy.

FIGURE 4S-13  Two examples of pelvic “ears,” a normal variant of development.



The Pelvic Girdle  |  The Ilium 4S-129

FIGURE 4S-15  Old healed avulsive lesions of the anterior inferior iliac spines.

A

B FIGURE 4S-14  A, Large pelvic “ears” may be mistaken for a fracture in the anteroposterior view of the pelvis. B, Pelvic “ears” demonstrated in pelvic inlet view.

A

B FIGURE 4S-16  Pelvic digit with large extrailiac component. A, Frontal projection. B, Left posterior oblique projection.

4S-130 The Pelvic Girdle  |  The Ilium

FIGURE 4S-17  Ringlike lesion of the ilium in a 31-year-old man. It is probably a developmental defect in the bone and is of no clinical significance.

FIGURE 4S-18  Remnants of the synchondrosis between the ilium and ischium in a 12-year-old girl.



The Pelvic Girdle  |  The Pubis and Ischium 4S-131

THE PUBIS AND ISCHIUM

FIGURE 4S-19  Cephalad angulation of the beam may produce a double contour of the upper aspects of the superior pubic rami, which may be mistaken for periosteal proliferation.

FIGURE 4S-21  The ischial apophysis seen en face may simulate a fracture in adolescence.

FIGURE 4S-23  Normal irregularities of ossification of the ischia in adolescent children. These changes are usually asymmetric and disappear with age. They represent “tug” lesions caused by the pull of the hamstring muscles on the apophyses.

FIGURE 4S-20  Unilateral nondevelopment of the inferior pubic ramus on the left.

FIGURE 4S-22  The ischial apophysis seen en face unilaterally.

FIGURE 4S-24  Remnant of the ischial apophysis in a 22-year-old woman.

4S-132 The Pelvic Girdle  |  The Pubis and Ischium

A

B

FIGURE 4S-25  A, Simulated fracture of the ischium produced by superimposition of the ischial spine with the hip in internal rotation. B, The “fracture” is not seen with the hip in external rotation.

FIGURE 4S-26  Un-united inferior pubic ossification centers in a 25-year-old woman.

FIGURE 4S-27  Normal irregularities of the margins of the symphysis pubis in a 12-year-old girl.

FIGURE 4S-28  Unilateral pubic spurs. The condensing changes around the symphysis and the irregularity of the symphyseal margins are postpartum changes.



The Pelvic Girdle  |  The Pubis and Ischium 4S-133

FIGURE 4S-30  Developmentally wide symphysis pubis in a 12-year-old boy. FIGURE 4S-29  Normal malalignment and irregularities of the symphysis pubis in a 21-year-old woman.

FIGURE 4S-31  The ischial tuberosities projecting into the pelvis may be mistaken for expansile lesions.

FIGURE 4S-32  Postpartum symphyseal changes in the symphysis pubis with vacuum phenomenon.

FIGURE 4S-33  Spurs in the obturator foramen arising from the pubis, a finding usually seen in the elderly.

4S-134 The Pelvic Girdle  |  The Acetabulum

THE ACETABULUM

FIGURE 4S-34  Primary protrusio acetabulae in an 18-year-old woman.

FIGURE 4S-36  Tomogram showing pit for nutrient vessels in acetabulum (m). If completely superimposed on the femoral head, this shadow may simulate a destructive lesion.

FIGURE 4S-35  Ossicle at the triradiate cartilage in a 5-year-old boy.

FIGURE 4S-37  Accessory ossification centers (m) in a 14-year-old boy, with additional centers laterally (m 66).

FIGURE 4S-38  A nice demonstration of the secondary ossification centers of the acetabulum.



The Pelvic Girdle  |  The Acetabulum 4S-135

FIGURE 4S-39  An os acetabuli marginalis superior persisting into adult life in a 22-year-old man.

FIGURE 4S-40  The os acetabuli on the right. Note the corresponding appearance on the left.

FIGURE 4S-41  Two examples of the os acetabuli. This ossicle should be distinguished from calcification in the rectus femoris tendon insertion. (Ref: Kawashima A, et al: Para-acetabular periarthritis calcarea: Its radiographic manifestations. Skeletal Radiol 17:476, 1988.)

4S-136 The Pelvic Girdle  |  The Acetabulum

FIGURE 4S-42  Three examples of persistence of all or portions of secondary ossification centers of the acetabulum in adults. These may be mistaken for fractures.

FIGURE 4S-43  Incomplete closure of the os acetabuli marginalis superior producing apparent radiolucencies in the heads of the femurs in a 32-year-old man.

A

B

FIGURE 4S-44  Persistence of a secondary center of ossification of the posterior lip of the acetabulum that was mistaken for a fracture. A, Conventional film. B, Tomogram.



The Pelvic Girdle  |  The Acetabulum 4S-137

FIGURE 4S-45  Un-united apophysis on the right in a 20-year-old man. FIGURE 4S-46  Spurlike margins of the acetabulum (m). Note the un-united ossification center (m 6 ).

FIGURE 4S-47  The anterior lip of the acetabulum (m) and the posterior lip (m 6) may be identified in most individuals. Between them is a relative radiolucency, best seen on the right side.

FIGURE 4S-49  A bone island in the acetabulum.

FIGURE 4S-48  Simulated destructive lesion of the acetabulum (m), caused by an undulation in the anterior margin of the acetabulum coupled with superimposition of the shadow of the ischium (m 66). This might be mistaken for a lesion on the apex of the acetabulum.

FIGURE 4S-50  Variation in appearance of the acetabular notch on the left.

4S-138 The Pelvic Girdle  |  The Acetabulum

FIGURE 4S-51  Two examples of asymmetric lateral acetabular notches, which are also probably due to fossae in the acetabulum.

FIGURE 4S-52  Exaggeration of the normal acetabular roof sclerosis without joint disease. Note the os acetabuli on the right side.

CHAPTER

5

The Shoulder Girdle and Thoracic Cage PAGES

FIGURES

285 to 312

THE SCAPULA

5-1 to 5-72

312 to 321

THE CLAVICLE

5-73 to 5-104

322 to 334

THE STERNUM

5-105 to 5-137

335 to 353

THE RIBS

5-138 to 5-198

THE SCAPULA

FIGURE 5-2  The coracoid processes seen as separate bones in a 2-year-old child.

FIGURE 5-1  Premature appearance of the ossification centers of the acromion and coracoid in a 1-month-old child. The coracoid process is not usually seen until the third month or later, and the secondary center for the acromion is not usually seen until age 10 to 12 years.

285

286

The Shoulder Girdle and Thoracic Cage  |  THE SCAPULA

FIGURE 5-3  Development of the acromion processes as separate centers in a 1-year-old girl. This appearance is not to be mistaken for the acromial fracture associated with child abuse. (Ref: Currarino G, Prescott P: Fractures of the acromion in young children and a description of a variant in acromial ossification which may mimic a fracture. Pediatr Radiol 24:251, 1994.)

A

B

FIGURE 5-4  Normal appearance of the coracoid processes during growth. A, A 13-year-old boy before appearance of the secondary ossification center. B, A 15-year-old boy. Note secondary ossification centers for coracoid and acromion processes.

A

B

FIGURE 5-5  Appearance of the ossification center of the coracoid process in adolescence before fusion occurs. It may be mistaken for a fracture. A, Axillary projection. B, Arm elevated.

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FIGURE 5-6  Two examples of the secondary apophysis of the tip of the coracoid process.

B

A FIGURE 5-7  Nonunion of the ossification center of the distal coracoid. A, Plain film. B, CT scan.

288

The Shoulder Girdle and Thoracic Cage  |  THE SCAPULA

A

B

FIGURE 5-8  Accessory ossification center at the synchondrosis at the base of the coracoid in a 14-year-old boy. A, AP projection. B, Abduction film.

FIGURE 5-9  The same entity as described in Figure 5-8.

FIGURE 5-10  The normal closing acromial apophysis in a 13-year-old boy. The irregularity of the apophyseal line is normal. The distal end of the acromion ossifies irregularly in infants and may be misinterpreted as evidence of child abuse. (Ref: Kleinman PK, Spevak MR: Variations in acromial ossification simulating infant abuse in victims of sudden infant death syndrome. Radiology 180:185, 1991.)

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FIGURE 5-12  Multiple centers of ossifications of the acromial apophysis in a 12-year-old girl on CT scan. FIGURE 5-11  Normal irregularity of the acromion in a 12-year-old boy that was mistaken for a pathologic process.

FIGURE 5-13  The apophysis of the acromion in a 14-year-old boy, shown in axillary projection. This apophysis closes at age 18 to 20 years.

FIGURE 5-15  Un-united accessory ossification center for the acromion in a 38-year-old man.

FIGURE 5-14  Remnant of the line of closure of secondary ossification center for the acromion in an 18-year-old man.

FIGURE 5-16  The same entity illustrated in Figure 5-15.

290

The Shoulder Girdle and Thoracic Cage  |  THE SCAPULA

FIGURE 5-17  Two examples of the os acromiale. This secondary ossification center persists into adult life as a separate bone and is often mistaken for a fracture of the acromion process when seen in the axillary projection. It is usually, but not invariably, bilateral. (Refs: Park JG, et al: Os acromiale associated with rotator cuff impingement: MR imaging of the shoulder. Radiology 193:255, 1994; Edelson JG, et al: Os acromiale: Anatomy and surgical implications. J Bone Joint Surg Br 75:551, 1993.)

FIGURE 5-18  The os acromiale seen in the tangential view of the scapula.

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PART 1  |  CHAPTER 5



A

B FIGURE 5-19  A, Os acromiale visible on frontal film simulating a fracture. B, Axillary projection demonstrates the os acromiale.

FIGURE 5-20  Un-united secondary apophysis of the coracoid in frontal projection.

A

B

FIGURE 5-21  Acromial pseudospur produced by positioning. A, AP projection. B, Patient has assumed a kyphotic position. (Refs: Cone RO Jr, et al: Shoulder impingement syndrome: Radiographic evaluation. Radiology 150:29, 1984; Jim YF, et al: Shoulder impingement syndrome. Skeletal Radiol 21:449, 1992.)

292

The Shoulder Girdle and Thoracic Cage  |  THE SCAPULA

FIGURE 5-22  A 13-year-old boy showing the normal irregularity of the glenoid seen before the secondary centers develop.

FIGURE 5-23  The ring apophysis of the glenoid in a 10-year-old boy.

A

B FIGURE 5-24  Two examples of remnants of the ring apophysis in adults.

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PART 1  |  CHAPTER 5



FIGURE 5-25  Secondary ossification centers for the glenoid, which should not be mistaken for fractures. (Ref: Ogden JA, Phillips SB: Radiology of postnatal skeletal development. VII: The scapula. Skeletal Radiol 9:157, 1983.)

A

B

FIGURE 5-26  Ossicle at inferior aspect of the glenoid fossa as a remnant of the ring apophysis. A, A 32-year-old man. B, A 57-year-old man.

294

The Shoulder Girdle and Thoracic Cage  |  THE SCAPULA

FIGURE 5-27  Persistent glenoid apophysis.

FIGURE 5-29  Un-united portion of the glenoid apophysis seen in the axial projections may be mistaken for a fracture fragment.

FIGURE 5-28  Small ossicle at the superior margin of the glenoid in an adult. This may be mistaken for calcific tendinitis of the long head of the biceps tendon.

FIGURE 5-30  Persistence of the glenoid apophysis in an adult.

FIGURE 5-31  Small ossicle at the anterior margin of the glenoid.

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FIGURE 5-32  Apparent lucencies in the neck of the scapula caused by end-on projection of the coracoid (m). Note the position of coracoid tip (m 6).

FIGURE 5-33  The coracoid process seen in the oblique projection of the shoulder.

FIGURE 5-34  The coracoid process projected over the glenoid, simulating a fracture.

FIGURE 5-35  Three examples of developmental defects in the glenoid. Such defects may be similar in origin to the acetabular notch.

296

The Shoulder Girdle and Thoracic Cage  |  THE SCAPULA

FIGURE 5-36  Normal excrescences of the lower margin of the neck of the scapula that may be mistaken for periostitis.

FIGURE 5-37 

Normal radiolucency of the wing of the scapula, which may resemble a lytic lesion.

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PART 1  |  CHAPTER 5



FIGURE 5-38  Normally wide acromioclavicular joint and apparent malalignment in a 14-year-old girl (m). This appearance, if not compared with the opposite side, may be mistaken for an acromioclavicular separation. Note also the secondary ossification center for the tip of the acromion process (m 66).

A

B

FIGURE 5-39  Apparent widening of the acromioclavicular joint resulting from positioning. A, Anteroposterior projection with internal rotation. B, A 30 degree right posterior oblique projection with external rotation.

FIGURE 5-40  Same phenomenon as in Figure 5-39. Note also the apparent malalignment of the clavicle and acromion (right).

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298

A

B

FIGURE 5-41  Positioning of the arms in children may produce an appearance simulating acromioclavicular separation. A, External rotation. B, Internal rotation.

A

B

C FIGURE 5-42  Variations in configuration of the acromioclavicular joint. A, In most normal individuals, the inferior aspect of the clavicle is at the same level as the inferior aspect of the acromion. B, C, In a small percentage of normal individuals, however, the distal end of the clavicle lies above, as in this case, or below the acromion and this appearance might be interpreted as an acromioclavicular separation. This variation emphasizes the value of examining both sides. (Refs: Urist MR: Complete dislocations of the acromioclavicular joint. J Bone Joint Surg 28:813, 1946; Pettrone FA, Nirschl RP: Acromioclavicular dislocation. Am J Sports Med 6:160, 1978.)

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PART 1  |  CHAPTER 5



FIGURE 5-43  Unusually wide acromioclavicular joints in a normal individual. These measurements exceed the quoted normal range. Examination of both shoulders resolves the question of possible separation. (Refs: Petersson CJ, Redlund-Johnell I: Radiographic joint space in normal acromioclavicular joint. Acta Orthop Scand 54:431, 1983; Kern JW, Harris JH Jr: Case 752: Normal variant of the acromion simulating grade I acromioclavicular separation. Skeletal Radiol 21:419, 1992.)

FIGURE 5-44  Two examples of secondary ossification centers (infrascapular bone) of the inferior angle of the scapula in 16-year-old boys. These usually fuse by age 20 years.

300

The Shoulder Girdle and Thoracic Cage  |  THE SCAPULA

A

B FIGURE 5-45  A, B, Failure of development of an apophysis at the angle of the scapula on the right.

FIGURE 5-46  Developmental notchlike defects on the superior margins of the scapulae.

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A

B FIGURE 5-47  A, B, Unusual notch on the lateral margin of the scapula, which is best seen on internal rotation.

A

B FIGURE 5-48  A, B, Bilateral simulated fractures of the upper margins of the scapulae.

302

The Shoulder Girdle and Thoracic Cage  |  THE SCAPULA

A

B FIGURE 5-49  A, B, Two examples of simulated fractures of the scapulae produced by the spine of the scapula.

FIGURE 5-50  Clasplike cranial margin of the scapula, which produces a pseudoforamen. The thin sheet of bone that forms the fossa supraspinata appears to be absent. (Ref: Goldenberg DB, Brogdon BG: Congenital anomalies of the pectoral girdle demonstrated by chest radiography. J Can Assoc Radiol 18:472, 1967.)

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PART 1  |  CHAPTER 5



FIGURE 5-51  Examples of calcification of the transverse superior ligament of the scapula. (Ref: Kohler A, Zimmer EA: Borderlands of Normal and Early Pathologic Findings in Skeletal Radiography, 4th ed. New York, Thieme, 1993.)

A

B

FIGURE 5-52  A, B, Deep notch on the superior margin of the scapula (m). Note also partial formation of a coracoclavicular articulation (m 6) in A.

304

The Shoulder Girdle and Thoracic Cage  |  THE SCAPULA

FIGURE 5-53  Foramina-like defects in the superior border of the scapula.

FIGURE 5-54  Sclerotic margins of the scapular fossae.

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PART 1  |  CHAPTER 5



FIGURE 5-55  Irregularity of the entity seen in Figure 5-54.

FIGURE 5-56  Normal lucencies in the neck of the scapula that may be mistaken for destructive lesions. They probably represent the lucency of the cancellous bone of the glenoid marginated by the coracoid process.

306

The Shoulder Girdle and Thoracic Cage  |  THE SCAPULA

FIGURE 5-57  Striking example of the entity shown in the preceding figure mistaken for a true lesion. Note that it is not seen on the straight frontal projection (top right).

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PART 1  |  CHAPTER 5



FIGURE 5-58  Developmental defects of the scapula that may be mistaken for a pathologic process. (Refs: Cigtay OS, Mascatello VJ: Scapular defects: A normal variation. AJR Am J Roentgenol 132:239, 1979; Pate D, et al: Scapular foramina. Skeletal Radiol 14:270, 1985.)

FIGURE 5-59  Fossa in the neck of the scapula.

308

The Shoulder Girdle and Thoracic Cage  |  THE SCAPULA

FIGURE 5-60  “Fractures” of the scapula simulated by a superimposition of the free margin of the scapula.

FIGURE 5-62  Simulated fracture of the neck of the scapula produced by trabecular pattern.

FIGURE 5-61  Normal lateral curvature of the distal end of the scapula.

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PART 1  |  CHAPTER 5



FIGURE 5-63  Fat stripe of chest wall simulating a fracture of the scapula.

FIGURE 5-64  Two examples of vascular channels that might be mistaken for fractures.

FIGURE 5-65  Prominent vascular channel in the wing of the scapula.

310

The Shoulder Girdle and Thoracic Cage  |  THE SCAPULA

FIGURE 5-66  Two examples of articulations between the scapula and adjacent ribs.

FIGURE 5-67  Examples of the normal “vacuum” phenomenon in the shoulder joint.

A

B

FIGURE 5-68  A, B, “Vacuum” phenomenon in both shoulder joints. When the lucency is seen overlying only bone, as in B, it may be mistaken for fracture.

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PART 1  |  CHAPTER 5



FIGURE 5-69  Marked accentuation of the trabecular pattern of the scapula.

A

B FIGURE 5-70  A, B, Two examples of the increased density of the lateral margins of the scapulae.

The Shoulder Girdle and Thoracic Cage  |  THE CLAVICLE

312

FIGURE 5-71  Dysplastic scapulae with wide acromioclavicular joints and large, shallow glenoid fossae. (Refs: Resnick D, et al: Bilateral dysplasia of the scapular neck. AJR Am J Roentgenol 139:387, 1982; Trout TE, Resnick D: Glenoid hypoplasia and its relationship to instability. Skeletal Radiol 25:37, 1996.)

FIGURE 5-72  In children, conventional positioning of the arms for chest radiography may produce an appearance simulating dislocations of the shoulders.

THE CLAVICLE

A

B

FIGURE 5-73  Normal irregular appearance of the medial ends of the clavicles in an 18-year-old man. This appearance, before completion of development, may be misinterpreted as evidence of disease. A, Plain film. B, Tomogram.

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PART 1  |  CHAPTER 5



A

B

FIGURE 5-74  Asymmetric closure of secondary ossification centers of medial ends of clavicles in a 21-year-old man. A, Open apophysis (m). B, Closed apophysis. Note also deep rhomboid fossa in A (m 6 ).

FIGURE 5-75  Failure of the medial ends of the clavicles to develop completely in an otherwise normal adult.

FIGURE 5-76  An un-united ossification center for the medial end of the clavicle, which has persisted as a separate ossicle. Note cupped juvenile configuration of the adjacent end of the clavicle, in contrast to the opposite side.

FIGURE 5-77  Sclerosis of the medial ends of the clavicle in a healthy 41-year-old man. FIGURE 5-78  Unusually stout medial ends of the clavicles with cupping of the articular surfaces.

314

The Shoulder Girdle and Thoracic Cage  |  THE CLAVICLE

FIGURE 5-79  Three examples of unilateral bifid medial end of the clavicle.

FIGURE 5-80  Two examples of the canal for the middle supraclavicular nerve.

FIGURE 5-81  The canal for the supraclavicular nerve, which was mistaken for a fracture, in a 5-year-old boy.

A

B

FIGURE 5-82  The nutrient canal of the clavicle usually is located posteriorly and is not seen, but it may appear on the inferior border. (Ref: Ogden JA, et al: Radiology of postnatal skeletal development. III: The clavicle. Skeletal Radiol 4:196, 1979.)

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A

B FIGURE 5-83  The rhomboid fossa. A, Plain film. B, CT scan.

A

B

FIGURE 5-84  A, B, Examples of the rhomboid fossa, the site of attachment of the rhomboid ligament between the first rib and the clavicle. Note how it may simulate bone destruction.

FIGURE 5-85  Rhomboid fossae, which could be mistaken for cavitary lesions in the lung.

FIGURE 5-86  Grooves for the insertion of the coracoclavicular ligament.

316

The Shoulder Girdle and Thoracic Cage  |  THE CLAVICLE

FIGURE 5-87  Insertion of the coracoclavicular ligament in a 6-year-old child.

FIGURE 5-88  Three examples of ossification of the coracoclavicular ligament.

FIGURE 5-89  Examples of deep fossae in the distal portions of the clavicles that are probably related to the origins of the deltoid muscles.

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PART 1  |  CHAPTER 5



FIGURE 5-90  Three examples of the coracoclavicular joint, an anomalous articulation that develops in the coracoclavicular ligament and is usually of no clinical significance. (Ref: Haramati N, et al: Coraco-clavicular joint: Normal variant in humans. Skeletal Radiol 23:117, 1994.)

FIGURE 5-91  The costoclavicular joint, an anomalous articulation between the clavicle and the anterior aspect of the first rib. (Ref: Redlund-Johnell I: The costoclavicular joint. Skeletal Radiol 15:25, 1986.)

A

B FIGURE 5-92  A, B, Bilateral simulated fractures of the distal ends of the clavicles in a 16-year-old boy.

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318

A

B FIGURE 5-93  Simulated fracture of the distal end of the clavicle produced by a bony flange. A, Plain film. B, Tomogram.

FIGURE 5-94  Large distal ends of the clavicles may mimic lytic lesions because of the large amount of cancellous bone.

FIGURE 5-96  Duplication of the distal end of the clavicle. (Ref: Twig HL, Rosenbaum RC: Duplication of the clavicle. Skeletal Radiol 6:281, 1981.)

FIGURE 5-95  An accessory ossicle in the acromioclavicular joint.

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FIGURE 5-97  Unusual configuration of the distal end of the clavicle.

FIGURE 5-98  Partial duplication of the distal end of the clavicle.

FIGURE 5-99  Fish-mouth configuration of the distal end of the clavicle. This was present bilaterally.

320

The Shoulder Girdle and Thoracic Cage  |  THE CLAVICLE

FIGURE 5-100  There is wide normal variation in the alignment of the acromion and the clavicle. The inferior margin of the clavicle aligns with the lower margin of the acromion in 81% of patients. The clavicle projects above the acromion in 7%, projects below the acromion in 7%, and overrides the acromion in 5%. Both sides should be examined routinely to detect these variations. Top, Bilateral cephalad position of the distal ends of the clavicles in relationship to the acromion. Bottom, Very marked example of the same entity. (Ref: Keats TE, Pope TL Jr: The acromioclavicular joint: Normal variation and diagnosis of dislocation. Skeletal Radiol 17:159, 1988.)

FIGURE 5-101  Bilateral caudad position of the distal ends of the clavicles in relationship to the acromion.

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A

B

FIGURE 5-102  Apparent inferior displacement of the distal end of the clavicle in external rotation in right posterior oblique position (A) and normal relationship of the clavicle to the acromion in the internal rotation view made in AP projection (B). This phenomenon is the result of foreshortening of the clavicle and its superimposition on the acromion.

A

B

FIGURE 5-103  Apparent change in orientation of the clavicle at the acromioclavicular joint with rotation of the shoulder. A, External rotation. B, Internal rotation.

A

B

FIGURE 5-104  Apparent changes in the width of the acromioclavicular joint with rotation of the shoulder. A, External rotation. B, Internal rotation.

322

The Shoulder Girdle and Thoracic Cage  |  THE STERNUM

THE STERNUM

A

B

FIGURE 5-105  Variations in development of the sternum. A, B, Accessory ossification centers for the body of the sternum in a 5-month-old girl (m). These centers and duplication of the manubrial centers may be seen in the lateral projection (m 66). (Ref: Ogden JA, et al: Radiology of postnatal skeletal development. II: The manubrium and sternum. Skeletal Radiol 4:189, 1979.)

FIGURE 5-106  Duplication of the ossification centers of the lower portion of the body of the sternum in an 11-month-old child.

FIGURE 5-107  Delayed appearance of the ossification center of the manubrium in a neonate.

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FIGURE 5-108  The sternal ossification centers superimposed on the ribs in a badly positioned chest film, simulating healing rib fractures.

FIGURE 5-109  Double ossification centers of the manubrium in a normal 5-month-old boy. This duplication is frequently seen in Down syndrome but also occurs as a normal variant.

A

B

FIGURE 5-110  Double ossification centers of the manubrium in a 13-year-old boy that were mistaken for a fracture. A, Plain film. B, Tomogram.

324

The Shoulder Girdle and Thoracic Cage  |  THE STERNUM

A

B

FIGURE 5-112  Variations in development of the sternum. A, Development of the body of the sternum from only two centers. B, Marked variability in size of the centers of ossification of the body of the sternum.

FIGURE 5-111  Ossicle at the sternomanubrial joint, probably degenerative in origin.

A

B

C

FIGURE 5-113  Developmental absence of the ossification center of the sternum in a 2-year-old child. A, Plain film, showing absence of sternal ossification center. B, Sagittal fast spin-echo MR image. C, Sagittal fast spin-echo MR image with T2 weighting. (From Rush WJ, et al: “Missing” sternal ossification center: Potential mimicker of disease in young children. Radiology 224:120, 2002.)

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FIGURE 5-114  Nonsegmentation of the sternum in a 30-year-old man, probably secondary to premature fusion of centers.

FIGURE 5-115  Three examples of episternal processes.

326

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FIGURE 5-116  Examples of episternal bones in adults. (Refs: Brown WH: Episternal bones: A case report. Radiology 75:116, 1960; Stark P, et al: Episternal ossicles. Radiology 165:143, 1987.)

FIGURE 5-117  The manubrium in an 11-month-old child that was mistaken for a mediastinal mass.

FIGURE 5-118  The manubrium may simulate a mass if the patient is slightly rotated as in this case.

The Shoulder Girdle and Thoracic Cage  |  THE STERNUM

327

PART 1  |  CHAPTER 5



A

B

FIGURE 5-119  A, B, The manubrium resembling a mediastinal mass in two adults. Note in A the sclerosis of the borders of the manubrium, which may suggest a mass lesion with a calcified border.

FIGURE 5-120  Developmental irregularity of the superior margin of the sternum at the sternomanubrial joint in an adolescent boy. Defects of this type have been likened to Schmorl’s nodes of the spine. (Ref: Kohler A, Zimmer EA: Borderlands of Normal and Early Pathologic Findings in Skeletal Radiography, 4th ed. New York, Thieme, 1993.)

328

The Shoulder Girdle and Thoracic Cage  |  THE STERNUM

A

B

FIGURE 5-121  Anomalous development of the sternal segments in haphazard alignment in an 11-year-old boy. A, Oblique projection. B, Lateral projection.

FIGURE 5-122  Congenital bifid sternum, an unusual variant. Note the radiolucency in the midline in the frontal chest film (m) and the mass effect in the lateral film (m 6). (Courtesy Dr. W.P. Brown.) (Ref: Larsen LL, Ibach HF: Complete congenital fissure of the sternum. Am J Roentgenol Radium Ther Nucl Med 87:1062, 1962.)

The Shoulder Girdle and Thoracic Cage  |  THE STERNUM

329

PART 1  |  CHAPTER 5



FIGURE 5-123  Bifid sternum.

A

B

FIGURE 5-124  Bifid manubrium. A, Axial CT scan. B, Oblique coronal CT reconstruction. C, Volume-rendering CT image with right oblique projection. (From Han DH, Ahn MI, et al: An asymptomatic young woman with abnormal manubrium sterni: Diagnosis and discussion. Skeletal Radiol (2009) 38:1009. With kind permission from Springer Science 1 Business Media.)

C

330

The Shoulder Girdle and Thoracic Cage  |  THE STERNUM

FIGURE 5-125  Two examples of sternal foramina, a finding of no significance. (Ref: Resnik CS, Brower AC: Midline circular defect of the sternum. Radiology 130:657, 1979.)

FIGURE 5-126  Sternal foramen on CT scan. (Courtesy Dr. D.B. Bach.) FIGURE 5-127  Variations in configuration of the xiphoid process and calcified costal cartilage may simulate destructive or neoplastic lesions of the sternum, particularly if there are symptoms referable to this area. (From Keats TE: Four normal anatomic variations of importance to radiologists. Am J Roentgenol Radium Ther Nucl Med 78:89, 1957.)

The Shoulder Girdle and Thoracic Cage  |  THE STERNUM

331

PART 1  |  CHAPTER 5



A

B

FIGURE 5-128  A, Plain film. Simulated mass lesion of the sternum produced by the xiphoid process and calcified costal cartilage (m). B, Tomogram. Note posterior curvature of the xiphoid process, which contributes to this misleading appearance (m 6 ).

FIGURE 5-129  Costal cartilage simulating a mass at the xiphoid.

FIGURE 5-130  The normal junction of the xiphoid process and body of the sternum, not to be mistaken for a fracture.

332

The Shoulder Girdle and Thoracic Cage  |  THE STERNUM

FIGURE 5-131  Marked anterior angulation of the xiphoid process.

FIGURE 5-132  Gap between the sternum and xiphoid simulating a fracture dislocation.

FIGURE 5-133  Gap between the sternum and xiphoid simulating a destructive lesion in a 25-year-old man.

The Shoulder Girdle and Thoracic Cage  |  THE STERNUM

333

PART 1  |  CHAPTER 5



FIGURE 5-134  Unusual partitioned xiphoid processes.

FIGURE 5-135  Bifid xiphoid process.

334

The Shoulder Girdle and Thoracic Cage  |  THE STERNUM

FIGURE 5-136  Bifid xiphoid process with one limb directed anteriorly.

FIGURE 5-137  Elongated xiphoid process directed anteriorly. This type of xiphoid may be jointed as well. The anterior direction may produce an apparent epigastric mass on clinical examination. (Ref: Sanders PC, Knight RW: Radiologic appearance of the xiphoid process presenting as an upper abdominal mass. Radiology 141:489, 1981.)



The Shoulder Girdle and Thoracic Cage  |  THE RIBS

335

FIGURE 5-138  Simulated cupping of the anterior ends of the ribs produced by lordotic projection.

PART 1  |  CHAPTER 5

THE RIBS

FIGURE 5-139  Large anterior ends of the ribs simulating extrapleural masses in an 8-month-old infant.

FIGURE 5-141  Hypoplasia of first rib on the right.

FIGURE 5-140  Well-developed cervical ribs in an adult.

FIGURE 5-142  Cervical rib articulating at its distal end with an additional bony element.

336

The Shoulder Girdle and Thoracic Cage  |  THE RIBS

FIGURE 5-143  Right cervical rib articulating with the first rib.

FIGURE 5-144  Accessory rib elements at transverse process of T1.

FIGURE 5-145  Jointed ligamentous calcifications between the transverse process of T1 and the first rib.

FIGURE 5-146  The patient presented with a hard right supraclavicular mass, which is explained by the anomalous arrangement of the first and second ribs. Such variants may efface the supraclavicular fossa and simulate a mass. (Ref: Fakhry SM, Thomas CG Jr: Pseudotumor of the supraclavicular fossa. South Med J 79:822, 1986.)

FIGURE 5-147  Duplication of the first rib.

The Shoulder Girdle and Thoracic Cage  |  THE RIBS

337

PART 1  |  CHAPTER 5



A

B FIGURE 5-148  Anomalous articulation in the first ribs, simulating a fracture in A and a mass lesion in B.

FIGURE 5-149  Three examples of anomalous articulations in the midportion of the first ribs simulating fractures (m 6).

338

The Shoulder Girdle and Thoracic Cage  |  THE RIBS

FIGURE 5-150  Two examples of anomalous articulations in the left first rib.

FIGURE 5-151  Pseudoarticulation of the posterior ribs seen by CT scan.

FIGURE 5-152  Jointed second rib.

FIGURE 5-154  Developmental absence of the first ribs. Note that the costal cartilages have formed even in the absence of the ribs. FIGURE 5-153  Bilateral failure of the first costal cartilages to unite with the first rib.

The Shoulder Girdle and Thoracic Cage  |  THE RIBS

339

PART 1  |  CHAPTER 5



A

B FIGURE 5-155  A, B, Marked overgrowth of the costal cartilage of the first rib protrudes anteriorly.

FIGURE 5-156  Two examples of normal areas of lucency in the anterior ends of the first ribs. These areas may be unilateral or bilateral, are fairly constant in their location, and should not be confused with areas of bone destruction.

340

The Shoulder Girdle and Thoracic Cage  |  THE RIBS

FIGURE 5-158  Spurlike process arising from the anterior portion of the first rib. FIGURE 5-157  Huge fossae in the anterior ends of the first ribs, as in Figure 5-156.

FIGURE 5-159  Developmental fusion between the anterior ends of the first and second ribs.

FIGURE 5-160  Anomalous development of the right fifth rib that might simulate a pneumothorax.

The Shoulder Girdle and Thoracic Cage  |  THE RIBS

341

PART 1  |  CHAPTER 5



FIGURE 5-161  Bridging between the second and third ribs anteriorly.

FIGURE 5-162  Fusion of the posterior portions of the right fifth, sixth, and seventh ribs, which can be seen in the lateral projection as well.

342

The Shoulder Girdle and Thoracic Cage  |  THE RIBS

FIGURE 5-163  Fusion of the posterior portions of the fourth and fifth ribs in a 12-year-old boy.

FIGURE 5-164  Extensive developmental fusion of the posterior ribs.

FIGURE 5-165  Localized developmental fusion of portions of the posterior ribs may simulate parenchymal lesions or pneumothorax.

FIGURE 5-166  An osseous bridge between the posterior portions of the third and fourth ribs.

The Shoulder Girdle and Thoracic Cage  |  THE RIBS

343

PART 1  |  CHAPTER 5



A

C

B

D

FIGURE 5-167  Very large calcified costal cartilages simulate an intrathoracic lesion in both projections. A, B, 74-year-old man. C, D, 58-year-old man. The first sternocostal joint may be classified as either a synchondrosis or a synostosis, but a joint cavity lateral to the first sternocostal joint may be present. (Ref: Schils JP, et al: Sternocostal joints: Anatomic, radiographic and pathologic features in adult cadavers. Invest Radiol 24:596, 1989.)

FIGURE 5-168  Very large hypertrophied costal cartilage of the first ribs with marked intrathoracic extension seen in lateral projection.

344

The Shoulder Girdle and Thoracic Cage  |  THE RIBS

FIGURE 5-169  The same entity as in Figure 5-168 but in a more exaggerated form.

FIGURE 5-170  Developmental spurs at the costovertebral junctions.

FIGURE 5-171  Spur at the inferior aspect of the costovertebral articulation of the fourth rib.

The Shoulder Girdle and Thoracic Cage  |  THE RIBS

345

PART 1  |  CHAPTER 5



FIGURE 5-172  The costoclavicular joint. This joint is a variant of the ligamentous connection between the medial end of the clavicle and the first rib. (From Redlund-Johnell I: The costoclavicular joint. Skeletal Radiol 15:25, 1986.)

A

B FIGURE 5-173  Anomalous development of fourth and fifth ribs with articulation. A, Plain film. B, CT scan.

FIGURE 5-174  Bifid anterior end of the fourth rib.

FIGURE 5-175  Marked cephalad angulation of the posterior portion of the fourth rib (white arrows) with fusion to the adjacent third rib (black arrow).

346

The Shoulder Girdle and Thoracic Cage  |  THE RIBS

FIGURE 5-176  Two examples of pseudoerosion of the ribs. Loss of bone from the superior aspects of the ribs may be seen in a variety of pathologic processes, particularly in connective tissue diseases, but may also be seen in normal individuals with increasing age. (Ref: Keats TE: Superior marginal rib defects in restrictive lung disease. Am J Roentgenol Radium Ther Nucl Med 124:449, 1975.)

FIGURE 5-177  Two examples of simulated destruction of the inferior aspects of the posterior portions of the middle ribs. This variation is commonly seen and is caused by the thin flange of bone at the lower portions of these ribs.

FIGURE 5-178  Simulated “cysts” of proximal rib ends produced by cancellous bone.

FIGURE 5-179  Lucencies in the tubercles of the proximal ends of the ribs.

The Shoulder Girdle and Thoracic Cage  |  THE RIBS

347

PART 1  |  CHAPTER 5



A

B

C FIGURE 5-180  Degeneration of the costochondral articulation which superimposes on the neural canal in lateral projection and may be mistaken for a parenchymal lesion. A, Oblique projection. B, Lateral projection. C, CT scan. (From Leibowitz RT, Keats TE: Degeneration of the costovertebra articulation: A cause of pulmonary pseudolesion. Emerg Radiol 10:250, 2004.)

348

The Shoulder Girdle and Thoracic Cage  |  THE RIBS

FIGURE 5-181  Normal exaggeration of the curve of the necks of the ribs simulating rib notching.

FIGURE 5-182  Normal exaggeration of curvature of the necks of the lower ribs.

FIGURE 5-184  Developmental variation in contour of midchest with a tucklike configuration of the ribs. This variant is probably caused by the presence of developmentally short ribs, which are often seen in the sixth, seventh, and eighth positions. (Ref: Sheflin JR: Short rib(s). AJR Am J Roentgenol 165:1548, 1995.)

FIGURE 5-183  Companion shadows along lower rib margins produced by thin bony flanges.

The Shoulder Girdle and Thoracic Cage  |  THE RIBS

349

PART 1  |  CHAPTER 5



FIGURE 5-185  Intrathoracic rib, a rare anomaly of no clinical significance. (Ref: Weinstein AS, Mueller CF: Intrathoracic rib. Am J Roentgenol Radium Ther Nucl Med 94:587, 1965.)

FIGURE 5-186  Two additional examples of intrathoracic ribs.

350

The Shoulder Girdle and Thoracic Cage  |  THE RIBS

FIGURE 5-188  Anomalous development of the twelfth ribs.

FIGURE 5-187  Intra-abdominal rib.

A

B FIGURE 5-189  A, Duplication of the left eleventh rib. B, These ribs take a marked intra-abdominal course.

FIGURE 5-190  Unilateral development of the twelfth rib.

FIGURE 5-191  Unilateral development of the twelfth rib simulating a fracture (m). Note the elongated transverse process on the opposite side (m 6 ).

The Shoulder Girdle and Thoracic Cage  |  THE RIBS

351

PART 1  |  CHAPTER 5



FIGURE 5-192  Anterior rib ends simulating nodular lesions in the lung.

FIGURE 5-193  Two examples of the spinal transverse process simulating a pulmonary nodule. (Ref: Shortsleeve MJ, Foster SC: Pulmonary pseudonodule. Radiology 131:311, 1979.)

352

The Shoulder Girdle and Thoracic Cage  |  THE RIBS

FIGURE 5-194  Marked costal cartilage calcification in a 28-year-old woman.

FIGURE 5-195  Ring-shaped costal cartilage calcification simulating a cavitary lesion in the lung.

FIGURE 5-196  Circular costal cartilage calcifications suggesting cavitary lesions in the lungs.

The Shoulder Girdle and Thoracic Cage  |  THE RIBS

353

PART 1  |  CHAPTER 5



FIGURE 5-197  Costal cartilage calcification simulating vascular calcification.

FIGURE 5-198  Linear costal cartilage calcification overlying the left kidney may be mistaken for a renal calculus.

CHAPTER

5

The Shoulder Girdle and Thoracic Cage

FIGURES

THE SCAPULA

5S-1 to 5S-34

THE CLAVICLE

5S-35 to 5S-55

THE STERNUM

5S-56 to 5S-60

THE RIBS

5S-61 to 5S-95

THE SCAPULA

FIGURE 5S-1  Normal appearance of the ossification centers of the coracoid processes in a 5-year-old boy.

5S-139

5S-140 The Shoulder Girdle and Thoracic Cage  |  THE SCAPULA

FIGURE 5S-2  The apophysis of the coracoid process mistaken for a fracture in a 14-year-old boy.

A

B FIGURE 5S-3  A, B, Persistent primary coracoid apophysis in an adult. (Courtesy Dr. H.P.J. Raat.)

FIGURE 5S-4  The synchondrosis of the base of the coracoid in a 15-yearold boy that simulates a cleft in the glenoid, as seen in axillary projection. FIGURE 5S-5  Failure of union of the secondary apophysis of the coracoid persisting as a separate bone, the coracoid bone.



The Shoulder Girdle and Thoracic Cage  |  THE SCAPULA 5S-141

FIGURE 5S-6  Unusually long and stout acromion processes in a 6-year-old boy.

FIGURE 5S-7  Unusually stout acromion in an adult.

A

B FIGURE 5S-8  A, B, Normal closing acromial apophyses. Note the irregular mineralization and density of the center in B.

5S-142 The Shoulder Girdle and Thoracic Cage  |  THE SCAPULA

FIGURE 5S-9  Persistent apophysis of the acromion in a 17-year-old boy. The opposite side was closed.

FIGURE 5S-10  The apophysis of the end of the acromion in a 16-year-old boy should not be mistaken for a fracture.

FIGURE 5S-11  The os acromiale may occasionally be seen in the frontal projection (left) and in the axillary projection (right).



The Shoulder Girdle and Thoracic Cage  |  THE SCAPULA 5S-143

A

B FIGURE 5S-12  A, B, Os acromiale with crenated appearance of the acromion.

FIGURE 5S-13  Normal fossae in the acromion process simulating a destructive lesion.

A

B FIGURE 5S-14  The ring apophysis of the glenoid fossa in children. A, An 8-year-old boy. B, A 13-year-old boy.

5S-144 The Shoulder Girdle and Thoracic Cage  |  THE SCAPULA

FIGURE 5S-15  Secondary centers of ossification of the glenoid. Note the large apophysis at the superior margin.

FIGURE 5S-16  Failure of fusion of the apophysis at the superior margin of the glenoid in an adult.

FIGURE 5S-17  Persistent glenoid apophysis in a 65-year-old man.

FIGURE 5S-18  Small ossicle at the margin of the glenoid fossa that may represent a remnant of the apophysis. Left, Frontal projection. Right, Axillary projection.



The Shoulder Girdle and Thoracic Cage  |  THE SCAPULA 5S-145

A

B

FIGURE 5S-19  A, B, Bilateral small excrescences on the inferior neck of the scapula adjacent to the glenoid that are of no clinical significance.

FIGURE 5S-20  An example of normal but apparently separated acromioclavicular joints. Note also the unusual width of the joint.

5S-146 The Shoulder Girdle and Thoracic Cage  |  THE SCAPULA

FIGURE 5S-22  An infrascapular bone simulating a rib fracture.

FIGURE 5S-21  An infrascapular bone that was mistaken for a lung lesion.

FIGURE 5S-23  Hooklike configuration of the distal angle of the scapula.



The Shoulder Girdle and Thoracic Cage  |  THE SCAPULA 5S-147

FIGURE 5S-24  Double cortical lines of the scapular spine in a 3-year-old child.

FIGURE 5S-25  Double contour of the upper margins of the scapulae. (Courtesy Dr. J.C. Hoppel.)

FIGURE 5S-26  The superior end of the body of the scapula simulating a fracture fragment.

FIGURE 5S-27  The margin of the scapular fossa simulating a wire or catheter.

5S-148 The Shoulder Girdle and Thoracic Cage  |  THE SCAPULA

FIGURE 5S-28  Foramen in the wing of the scapula.

FIGURE 5S-30  Large nutrient foramen of the scapula.

FIGURE 5S-29  Tangential views of the scapula with simulated fractures produced by the overlapping shadow of the free border on the body of the scapula.



The Shoulder Girdle and Thoracic Cage  |  THE CLAVICLE 5S-149

FIGURE 5S-32  Branched vascular channel in the scapula simulating a fracture. FIGURE 5S-31  Vascular groove in the neck of the scapula.

FIGURE 5S-34  Simulated dislocation of the right shoulder secondary to positioning in an elderly individual.

FIGURE 5S-33  Marked accentuation of the trabecular pattern of the scapula in a 49-year-old woman. CT and MRI showed no abnormality.

THE CLAVICLE

FIGURE 5S-36  Normal asymmetry of the medial ends of the clavicles.

FIGURE 5S-35  Secondary ossification centers of the medial ends of the clavicles in a 20-year-old man.

5S-150 The Shoulder Girdle and Thoracic Cage  |  THE CLAVICLE

FIGURE 5S-37  An accessory ossicle at the medial end of the clavicle.

FIGURE 5S-38  Simulated fracture of the medial end of the clavicle produced by overlapping shadows of the transverse processes, rhomboid fossa, and ribs.

FIGURE 5S-39  A dense closed epiphyseal line in an adult, simulating a fracture with overriding.

FIGURE 5S-40  The canal for the supraclavicular nerve, which was mistaken for a fracture, in a 43-year-old man.

FIGURE 5S-41  The fossa at the entry point of the nutrient vessel and the canal of the nutrient vessel are nicely demonstrated in this patient.



The Shoulder Girdle and Thoracic Cage  |  THE CLAVICLE 5S-151

A

B

C D FIGURE 5S-42  A through D, Examples of the rhomboid fossa, the site of attachment of the rhomboid ligament between the first rib and the clavicle. Note how it may simulate bone destruction and the fact that it is not necessarily bilaterally symmetric.

FIGURE 5S-44  Bilateral rhomboid fossae simulating apical pneumothoraces.

FIGURE 5S-43  An exostosis-like extension of the clavicle at the usual site of the rhomboid fossa.

FIGURE 5S-45  Groove for the coracoclavicular ligament simulating an erosion.

5S-152 The Shoulder Girdle and Thoracic Cage  |  THE CLAVICLE

FIGURE 5S-46  Groove for the insertion of the coracoclavicular ligament mistaken for a fracture. Left, External rotation. Right, Internal rotation.

FIGURE 5S-48  Abortive articulation between the clavicle and the first rib.

FIGURE 5S-47  Examples of wavy inferior margins of the clavicles thought to be related to the subclavian arteries. Top, Bilateral. Bottom, Unilateral on the right. It has also been suggested that this configuration may be the product of rotation of the clavicle with aging. (Refs: Levin B: The unilateral wavy clavicle. Skeletal Radiol 19:519, 1990; and Freiberger RH: Letter to the editor. Skeletal Radiol 20:192, 1991.)

FIGURE 5S-50  Unusual appearance of the clavicle produced by overlapping shadow of the scapula.

FIGURE 5S-49  Developing coracoclavicular articulation in a 9-year-old child.



The Shoulder Girdle and Thoracic Cage  |  THE CLAVICLE 5S-153

FIGURE 5S-51  The shafts in the clavicles of this patient are unusually stout in comparison with the medial and distal portions.

FIGURE 5S-52  Normal flange on the distal end of the clavicle in a 4-year-old boy.

FIGURE 5S-53  Irregular appearance of the distal end of the clavicle before growth is completed in a 16-year-old.

A

B FIGURE 5S-54  A, B, Unusual ossicles on the superior aspects of both clavicles in a 60-year-old man.

FIGURE 5S-55  Unusual duplication anomaly of the distal end of the clavicle. This appearance may also be simulated by ossification in the coracoclavicular ligament. (Ref: Schubert F: ‘Duplication’ of the clavicle or ossification in the coracoclavicular ligament. Australas Radiol 41:70, 1997.)

5S-154 The Shoulder Girdle and Thoracic Cage  |  THE STERNUM

THE STERNUM

FIGURE 5S-56  Double ossification centers of the manubrium in an adult.

FIGURE 5S-57  The sternomanubrial joint may simulate a fracture of the dorsal spine in the frontal plane.

FIGURE 5S-58  Partial bifid sternum with union at distal end. (Courtesy Dr. W.E. Litterer.)

FIGURE 5S-59  Indentation on anterior surface of the last sternal segment.



The Shoulder Girdle and Thoracic Cage  |  THE RIBS 5S-155

FIGURE 5S-60  Accessory center (m) for the xiphoid process (m 6 ).

THE RIBS

FIGURE 5S-62  The anterior end of a cervical rib simulating a parenchymal lesion.

FIGURE 5S-61  Cervical rib in a 2-week-old infant.

FIGURE 5S-63  Large bilateral cervical ribs, which articulate with the first ribs.

5S-156 The Shoulder Girdle and Thoracic Cage  |  THE RIBS

FIGURE 5S-64  Un-united apophysis of the first rib in a 28-year-old man.

FIGURE 5S-65  Two more examples of anomalous articulations in the left first rib.

FIGURE 5S-66  Striking increase in density of the first ribs in a normal 29-yearold man.

FIGURE 5S-67  Anomalous development of the first rib (m) with the costal cartilage un-united to the rib (m 6).



The Shoulder Girdle and Thoracic Cage  |  THE RIBS 5S-157

FIGURE 5S-68  Failure of first ribs to join costal cartilages.

FIGURE 5S-69  Unusual calcification of the costal cartilages of the first and second ribs.

FIGURE 5S-71  Articulation between the first and second ribs on the right. FIGURE 5S-70  Fusion of the anterior portions of the first and second ribs.

FIGURE 5S-72  Fusion between posterior portions of the fourth and fifth ribs.

5S-158 The Shoulder Girdle and Thoracic Cage  |  THE RIBS

FIGURE 5S-73  Large first rib with bifurcated anterior end mistaken for a mass lesion. Left, Plain film. Right, Tomogram.

FIGURE 5S-74  Variations in development of the costal cartilages of the first ribs.

A

B FIGURE 5S-75  Nodular calcification of the costal cartilage of the first rib simulating a lung lesion.



The Shoulder Girdle and Thoracic Cage  |  THE RIBS 5S-159

FIGURE 5S-76  Spurs at the first costochondral junction.

A

FIGURE 5S-77  The costochondral junction simulating a pneumothorax.

B FIGURE 5S-78  Ossicles related to rib ends. A, Anterior rib end. B, Posterior rib end.

FIGURE 5S-79  Articulation between the first and second ribs.

5S-160 The Shoulder Girdle and Thoracic Cage  |  THE RIBS

FIGURE 5S-80  Articulation between the posterior aspects of the third and fourth ribs, which was mistaken for a parenchymal lesion. A, PA projection. B, Right posterior oblique projection.

FIGURE 5S-81  Superimposition of the clavicle and first rib simulating a destructive lesion in the second rib.

FIGURE 5S-82  Anomalous development of the anterior end of the fourth rib.



The Shoulder Girdle and Thoracic Cage  |  THE RIBS 5S-161

FIGURE 5S-83  Grooves in the lower margins of the ribs, which might be mistaken for the lung edge of a pneumothorax.

FIGURE 5S-84  This thin flange of bone will also result in an apparent fusiform appearance of the rib, which should not be misinterpreted as a pathologic process.

5S-162 The Shoulder Girdle and Thoracic Cage  |  THE RIBS

FIGURE 5S-85  Localized protuberances on the anterior aspects of the second and third ribs.

FIGURE 5S-87  Articulation between two ribs.

FIGURE 5S-86  Enlarged costovertebral articulations produced by hypertrophic changes.



The Shoulder Girdle and Thoracic Cage  |  THE RIBS 5S-163

FIGURE 5S-88  Articulation between two ribs.

FIGURE 5S-89  Soft tissue companion shadows of the upper margins of the lower anterior ribs.

FIGURE 5S-91  Gastric contents simulating sclerotic lesion of the rib.

FIGURE 5S-90  Normal bulging of the ninth ribs bilaterally. (Courtesy Dr. R.M. Webster.)

5S-164 The Shoulder Girdle and Thoracic Cage  |  THE RIBS

FIGURE 5S-92  Transverse process in cross-section simulating cavitary lung lesion.

FIGURE 5S-93  Extensive costal cartilage calcification in a 41-year-old man.

FIGURE 5S-94  Calcified costal cartilage misinterpreted as a metastatic deposit. The cartilage is jointed (m). Left, Frontal projection. Right, Oblique projection.



The Shoulder Girdle and Thoracic Cage  |  THE RIBS 5S-165

FIGURE 5S-95  “Dislocations” of the twelfth ribs simulated by the inability to visualize the transverse processes.

CHAPTER

6

The Upper Extremity PAGES

FIGURES

355 to 389 355 to 373 373 to 389

THE HUMERUS The Proximal Portion of the Humerus The Distal Portion of the Humerus

6-1 to 6-88 6-1 to 6-46 6-47 to 6-88

389 to 413 389 to 401 401 to 413

THE FOREARM The Proximal Portion of the Forearm The Distal Portion of the Forearm

6-89 to 6-157 6-89 to 6-120 6-121 to 6-157

414 414 414 422 424 432 435 437 447 449 454 467 469

THE HAND The Carpals The Accessory Ossicles The Carpals in General The Capitate and Lunate Bones The Hamate Bone The Trapezium and Trapezoid Bones The Navicular Bone The Triquetrum Bone The Pisiform Bone The Metacarpals The Sesamoid Bones The Fingers

6-158 6-158 6-158 6-179 6-184 6-205 6-211 6-218 6-238 6-244 6-257 6-293 6-300

354

to to to to to to to to to to to to to

484 454 421 424 432 435 437 446 449 454 466 469 484

to to to to to to to to to to to to to

6-340 6-256 6-178 6-183 6-204 6-210 6-217 6-237 6-243 6-256 6-292 6-299 6-340

The Upper Extremity  |  THE HUMERUS

355

THE HUMERUS The Proximal Portion of the Humerus

FIGURE 6-1  Bilateral duplicated capital humeral epiphyses in a 13-month-old child.

FIGURE 6-2  Two examples of simulated periostitis produced by the shadow of the bicipital groove in neonates, which is seen with the arm externally rotated or elevated.

PART 1  |  CHAPTER 6



356

The Upper Extremity  |  THE HUMERUS

A

B FIGURE 6-3  Deep bicipital grooves that may be mistaken for an abnormality. A, A 7-month-old child. B, A 2-year-old child.

A

B

FIGURE 6-4  A, The bicipital groove in internal rotation should not be mistaken for an impaction fracture (trough sign). B, External rotation shows no abnormality.

FIGURE 6-5  Bicipital groove mistaken for a Hill-Sachs deformity.

The Upper Extremity  |  THE HUMERUS

357

PART 1  |  CHAPTER 6



A

B

FIGURE 6-6  A, In the axillary projection, the anterior aspect of the humeral head may simulate a reverse Hill-Sachs impaction fracture. B, T2-weighted MR image shows no abnormality.

FIGURE 6-7  On internal rotation, the humeral head may have a cystlike appearance.

FIGURE 6-8  Beaking of the epiphyseal line in a 16-year-old boy. This beaking, particularly of the epiphysis, is seen elsewhere and should not be mistaken for an avulsion injury. (From: Keats TE, Harrison RB: The epiphyseal spur. Skeletal Radiol 5:175, 1980.)

FIGURE 6-9  The normal epiphyseal lines of the proximal humerus in a 17-year-old boy. A, External rotation. B, Internal rotation. The epiphyseal line in B at times is mistaken for a fracture.

A

B

358

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FIGURE 6-10  The lateral aspect of the epiphyseal line is normally quite wide and should not be mistaken for evidence of a fracture.

FIGURE 6-11  The closed epiphyseal line in an 18-year-old man simulates a lesion on CT scan.

FIGURE 6-12  Bilateral upper humeral notches in an 11-year-old boy. Seen in children between 10 and 16 years of age, such notches represent a phase of growth. They are probably similar to the cortical lesions seen in the distal humerus, the distal end of the radius, the distal end of the femur, and the proximal end of the tibia. (Ref: Ozonoff MB, Ziter FM Jr: The upper humeral notch: A normal variant in children. Radiology 113:69, 1974.)

The Upper Extremity  |  THE HUMERUS

359

PART 1  |  CHAPTER 6



A

A1

B

B

1

FIGURE 6-13  Other examples of upper humeral notches. A, A1, A 12-year-old boy. B, B1, A 12-year-old girl. Note how these variants may resemble the changes of malignancy.

FIGURE 6-14  Very deep upper humeral notch in a 7-year-old boy.

360

The Upper Extremity  |  THE HUMERUS

A

B

FIGURE 6-15  Residual upper humeral notches in adults. A, A 28-year-old woman. B, A 29-year-old woman. C, A 35-year-old woman.

C

A

B FIGURE 6-16  A, B. The upper humeral notch shown as a radiolucency in internal rotation.

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361

PART 1  |  CHAPTER 6



A

B

FIGURE 6-17  A, Simulated fracture of the greater tuberosity produced by positioning in external rotation. B, No fracture seen with internal rotation.

FIGURE 6-18  Two examples of how projection of the cortex of the humeral neck can simulate periostitis.

362

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FIGURE 6-19  Examples of simulated destruction of the greater tuberosity. This appearance is the product of the lesser amount of cancellous bone present in this location. It is nicely demonstrated by MR images in Figure 6-20. (Ref: Resnick D, Cone RO 3rd: The nature of humeral pseudocysts. Radiology 150:27, 1984.)

FIGURE 6-20  T1-weighted and gradient echo T2-weighted MR images of the shoulder show the areas of cancellous bone in the greater tuberosity that give the appearance shown in Figure 6-19.

The Upper Extremity  |  THE HUMERUS

363

PART 1  |  CHAPTER 6



FIGURE 6-22  Epiphyseal and metaphyseal spurs in a 15-year-old boy.

FIGURE 6-21  A striking example of the pseudocyst of the greater tuberosity.

A

B

C

D

FIGURE 6-23  The lesser tuberosity seen in external rotation (A and B) and in internal rotation (C and D).

364

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FIGURE 6-24  Metaphyseal spurs in a 19-month-old child. These are normal variants of growth.

FIGURE 6-25  Cortical thickening underlying the deltoid muscle in a 2-month-old child.

FIGURE 6-26  Tendinous insertions in a 20-month-old child that may simulate periostitis.

The Upper Extremity  |  THE HUMERUS

365

PART 1  |  CHAPTER 6



B

A

FIGURE 6-27  A, B, The humeral pseudocyst in a 12-year-old boy.

A

B

FIGURE 6-28  A, B, Prominent deltoid muscle insertion in two projections in a 50-year-old man (m). The medial shadow in A is a soft tissue fold (m 6).

366

The Upper Extremity  |  THE HUMERUS

FIGURE 6-29  Unusually prominent deltoid muscle insertions seen bilaterally.

FIGURE 6-30  Localized cortical thickenings caused by a prominent deltoid muscle insertion.

The Upper Extremity  |  THE HUMERUS

367

PART 1  |  CHAPTER 6



B

A FIGURE 6-31  Large deltoid muscle insertion confirmed on axial MR image. A, Plain film. B, T1-weighted axial MR image.

368

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A

B

FIGURE 6-33  Radiolucencies produced by the insertion of the pectoralis major muscle. A, Plain film. B, Tomogram. (From: Brower AC: Cortical defect of the humerus at the insertion of the pectoralis major. AJR Am J Roentgenol 128:677, 1977.)

FIGURE 6-32  The deltoid insertion on a T1-weighted MR image.

FIGURE 6-34  The same entity as shown in Figure 6-33, seen here bilaterally in a heavily muscled 19-year-old man.

FIGURE 6-35  A discrete pectoralis major muscle insertion.

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369

PART 1  |  CHAPTER 6



A

B FIGURE 6-36  A, B, Insertion of the coracobrachialis muscle.

FIGURE 6-37  Cortical thickenings of the medial and posterior cortex at the insertion of the latissimus dorsi muscle in a 55-year-old man.

370

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FIGURE 6-38  Latissimus dorsi muscle insertions in a 68-year-old man with foci of endosteal thickening.

FIGURE 6-39  Spurlike insertion of the latissimus dorsi muscle.

A

B

FIGURE 6-40  A, Benign cortical defects of the humerus in a 4-year-old child (m 6). Note also the location and appearance of the ossification centers for the greater tuberosity and head of the humerus at this age (m 66). B, Five years later, the cortical defect in the left humerus has disappeared, and that in the right has left a sclerotic scar.

The Upper Extremity  |  THE HUMERUS

371

PART 1  |  CHAPTER 6



FIGURE 6-41  Multiple benign cortical defects of the proximal humerus. These fibrous lesions may be single or multiple and are of no clinical significance. (Ref: Silverman FN, Kuhn J: Caffey’s Pediatric X-Ray Diagnosis, 9th ed. St. Louis, Mosby, 1993.)

A

B

FIGURE 6-42  Two examples of “herringbone” trabecular pattern of the medullary cavity of the humerus.

C

FIGURE 6-43  A and B, Left humerus of a 26-year-old woman with a “herringbone” medullary pattern. C, The same patient’s right humerus 2 weeks after casting for a fracture of the surgical neck. Note the peculiar type of deossification, which occurs in patients with this type of medullary trabecular pattern and resembles metastatic neoplasm or multiple myeloma. (Ref: Keats TE, Harrison RB: A pattern of posttraumatic demineralization of bone simulating permeative neoplastic replacement: A potential source of misinterpretation. Skeletal Radiol 3:113, 1978.) On close inspection, this type of aggressive osteoporosis shows small cortical lucencies that help differentiate it from malignant neoplastic permeation. (Ref: Helms CA, Munk PL: Pseudopermeative skeletal lesions. Br J Radiol 63:461, 1990.)

372

A

The Upper Extremity  |  THE HUMERUS

C

B

FIGURE 6-44  A, B, Another example of “aggressive” osteoporosis, this one in a 50-year-old woman recently immobilized secondary to brain tumor. C, T1-weighted MR image shows normal fatty bone marrow.

B

A FIGURE 6-45  A, B, Intramedullary sclerosis of humerus in a 68-year-old woman similar to that seen in the femur of the elderly (see Fig. 7-70).

The Upper Extremity  |  THE HUMERUS

373

PART 1  |  CHAPTER 6



A

B

FIGURE 6-46  Two examples of physiologic “periostitis” of the newborn. A, A 3-month-old infant. B, An 8-month-old infant. This finding is not seen before age 1 month and is usually symmetric in distribution, although not necessarily concentric, and may be seen in only one view. (Ref: Shopfner CE: Periosteal bone growth in normal infants: A preliminary report. Am J Roentgenol Radium Ther Nucl Med 97:154, 1966.)

The Distal Portion of the Humerus

FIGURE 6-47  Normal thin flange of bone above the lateral epicondyle simulating periostitis (m). Note also the perforated olecranon fossa (m 66).

FIGURE 6-48  Another example of “periostitis” simulated by the lateral epicondylar flange.

374

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FIGURE 6-49  The epicondylar flange simulating a cortical fracture.

FIGURE 6-50  Olecranon foramen with marked sclerosis of its margins.

FIGURE 6-51  The supracondylar process. This vestigial structure is rarely associated with symptoms and occurs in about 1% of persons of European origin. Its axis is typically directed distally. (Ref: Barnard LB, McCoy SM: The supracondyloid process of humerus. J Bone Joint Surg Am 28:845, 1946.)

The Upper Extremity  |  THE HUMERUS

375

PART 1  |  CHAPTER 6



FIGURE 6-52  The supracondylar process in a 4-year-old boy.

FIGURE 6-53  A supracondylar process-directed cephalad rather than in the usual caudad direction.

376

The Upper Extremity  |  THE HUMERUS

FIGURE 6-54  Developmental cortical notch on the medial cortex of the humerus is of no significance. Its anatomic origin is uncertain.

FIGURE 6-55  Another example of the humeral cortical notch.

The Upper Extremity  |  THE HUMERUS

377

PART 1  |  CHAPTER 6



A

B

FIGURE 6-56  A, B, Two examples of small fossae on the anterior cortex of the distal humerus, which are probably developmental.

A

B

FIGURE 6-57  Variations in appearance of the olecranon fossa. A, Fossa is replaced by a complete foramen (m). B, Foramen is traversed by a bridge of bone (m 66).

378

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FIGURE 6-58  Simulated loose body or fracture produced by the ossification center for the olecranon process in a 7-year-old girl.

FIGURE 6-59  The normal rarefaction of bone of the distal humerus may simulate a lytic lesion on the lateral projection.

FIGURE 6-60  Apparent discontinuity of bone immediately above the epiphyseal line in a 12-year-old boy. This finding represents a variation in development of the metaphysis of a long bone in adolescence similar to the cortical lesions seen in the proximal end of the humerus, the distal radius, the distal end of the femur, and the proximal end of the tibia. This appearance may be misconstrued as evidence of dislocation of the epiphysis or a destructive lesion of the humerus. (Ref: Silberstein MJ, et al: Some vagaries of the capitellum. J Bone Joint Surg Am 61:244, 1979.)

The Upper Extremity  |  THE HUMERUS

379

PART 1  |  CHAPTER 6



FIGURE 6-61  The discontinuity seen in Figure 6-60 is now only minimally present in this 16-year-old boy, indicating the transient nature of this finding.

FIGURE 6-62  Early appearance of the ossification center for the trochlea in a 6-year-old girl. Rarely the trochlear ossification center may appear without evidence of a medial epicondylar center, as in this case. (Ref: Resnik CS, Hartenberg MA: Ossification centers of the pediatric elbow: A rare normal variant. Pediatr Radiol 16:254, 1986.)

380

The Upper Extremity  |  THE HUMERUS

FIGURE 6-63  Normal position of the ossification center for the lateral epicondyle in a child, simulating an avulsion.

FIGURE 6-64  Normal appearance and position of the ossification center for the medial epicondyle in a 7-year-old boy.

The Upper Extremity  |  THE HUMERUS

381

PART 1  |  CHAPTER 6



A

B

FIGURE 6-65  A, Simulated dislocation of the ossification center for the medial epicondyle caused by suboptimal patient positioning. B, Frontal projection. Note the absence of a medial hematoma, which would accompany a dislocation of the ossification center.

FIGURE 6-66  The medial epicondyle in the adult seen in off-lateral projection.

FIGURE 6-67  Normal irregularities and pseudofractures of the ossification centers of the distal humerus in a 10-year-old girl. Note the lack of bilateral symmetry of some of these defects.

382

The Upper Extremity  |  THE HUMERUS

FIGURE 6-68  A persistent epiphysis of the capitellum in an adult. Left and center, Radiographs. Right, Tomogram.

FIGURE 6-69  Bilateral cleft epiphyses for the medial epicondyle in a 15-year-old boy. The left elbow was immobilized for 2 weeks on the assumption that the cleft represented a fracture. (Ref: Harrison RB, Keats TE: Epiphyseal clefts. Skeletal Radiol 5:23, 1980.)

FIGURE 6-70  Marked asymmetry of ossification of the centers for the trochlea in an adolescent girl.

The Upper Extremity  |  THE HUMERUS

383

PART 1  |  CHAPTER 6



FIGURE 6-71  An example of how the epiphysis of the trochlea may be mistaken for a fracture in the lateral projection.

FIGURE 6-72  Asymmetric development of the epiphysis for the capitellum in a 12-year-old boy. Such normal asymmetries in architecture and rate of growth are particularly common in the elbow and should not be misconstrued as evidence of trauma.

A

B

FIGURE 6-73  A, Simulated fracture of the ossification center of the medial epicondyle in a 14-year-old boy, produced by the superimposed radiolucent shadow of the growth plate between the ossification center and the bony side wall of the humerus (m). Note also the unusual appearance of the trochlea resulting from filming in a slight degree of flexion (m 6 ). B, Note the radiolucency of the growth plate of the trochlea in lateral projection.

384

The Upper Extremity  |  THE HUMERUS

FIGURE 6-75  Several simulated fractures of the ossification centers of the distal humerus in an 11-year-old boy. Such irregularities of ossification are common.

FIGURE 6-74  Normal irregularities in ossification of the capitellum, which should not be mistaken for a fracture.

A

B

FIGURE 6-76  A and B, Normal asymmetry in development of ossification centers. In B, note the absence of the ossification center for the lateral epicondyle in an 11-year-old girl. (Ref: Silberstein MJ, et al: Some vagaries of the lateral epicondyle. J Bone Joint Surg Am 64:444, 1982.)

FIGURE 6-77  Incomplete union of ossification centers for the epicondyles in a 44-year-old woman.

The Upper Extremity  |  THE HUMERUS

FIGURE 6-78  Incomplete union of the ossification centers for the epicondyles in a 54-year-old woman.

FIGURE 6-79  Examples of failure of union of ossification centers in adults.

FIGURE 6-80  Projection of the middle eminence of the lower articular surface of the humerus.

385

PART 1  |  CHAPTER 6



386

The Upper Extremity  |  THE HUMERUS

FIGURE 6-81  Small bilateral ossicles related to the articular surface of the humerus. These may represent separate ossification centers for the middle eminence. Arthrograms indicate that they are enclosed in a lucent cartilage envelope.

FIGURE 6-82  An additional example of the entity shown in Figure 6-81.

A

B

FIGURE 6-83  A, B, Two examples of paratrochlear bones at the lateral humeral condyle. (Ref: Schwartz GS: Bilateral antecubital ossicles (fabella cubiti) and other accessory bones of the elbow. Radiology 69:730, 1957.)

The Upper Extremity  |  THE HUMERUS

387

PART 1  |  CHAPTER 6



FIGURE 6-84  Spurlike shadows probably representing the edge of the capitellum in an 11-year-old boy.

A

B

FIGURE 6-85  A, Simulated fracture through the epiphysis of the trochlea produced by angulation of the beam. B, Comparison view of the opposite elbow in true lateral projection shows a similar lucency without the simulated fracture.

388

The Upper Extremity  |  THE HUMERUS

FIGURE 6-86  Circumscribed radiolucencies in metaphyses caused by fossae above the capitellum.

FIGURE 6-87  The normal lucency just above the joint in lateral projection, which should not be mistaken for an elevated fat pad.

The Upper Extremity  |  THE FOREARM

389

PART 1  |  CHAPTER 6



FIGURE 6-88  The posterior fat pad may be seen in some normal individuals with the elbow in extension. Left, Partial flexion. Right, Extension.

THE FOREARM The Proximal Portion of the Forearm

A

B FIGURE 6-89  A, B, Normal asymmetry of development of the olecranon apophyses. Note irregular ossification in B.

390

The Upper Extremity  |  THE FOREARM

FIGURE 6-91  Patella cubiti in a more inferior position. FIGURE 6-90  Patella cubiti, a sesamoid bone in the triceps tendon. (Ref: Kattan KR, Babcock DS: Case report 105: Bilateral patella cubiti. Skeletal Radiol 4:249,1979.)

FIGURE 6-92  A separate nucleus of ossification for the olecranon process, not a fracture. (Ref: Silberstein MJ, et al: Some vagaries of the olecranon. J Bone Joint Surg Am 63:722, 1981.)

FIGURE 6-93  Other examples of separate apical nuclei of ossification for the olecranon process.

The Upper Extremity  |  THE FOREARM

FIGURE 6-94  A, Normal appearance of the uniting olecranon ossification center in an adolescent. B, Incomplete union of the ossification center of the olecranon process— not a fracture—in an adult.

A

FIGURE 6-95  Persistent unfused apophyses olecranon in a middleaged man.

FIGURE 6-96  Simulated fracture of the ulna produced by trabeculations in the shaft (m) and a small excrescence in the cortex just below the location of the distal end of the unossified apophysis (m 6).

391

PART 1  |  CHAPTER 6



B

392

The Upper Extremity  |  THE FOREARM

A

B FIGURE 6-97  Unusual development of the olecranon. A, Ossicle. B, Fossa.

FIGURE 6-98  Residual irregularity of the olecranon after closure of the apophysis in a 19-year-old man.

FIGURE 6-99  Normal foramina for nutrient vessels of the proximal ulna.

The Upper Extremity  |  THE FOREARM

393

PART 1  |  CHAPTER 6



FIGURE 6-100  Cancellous bone of the proximal ends of the ulnae, simulating destructive lesions in a 49-year-old man.

A

B FIGURE 6-101  Normal sclerotic appearance of the epiphyses of the radial heads in an 11-year-old boy.

394

The Upper Extremity  |  THE FOREARM

FIGURE 6-102  Cleft epiphysis of the radial head. (Ref: Harrison RB, Keats TE: Epiphyseal clefts. Skeletal Radiol 5:23, 1980.)

FIGURE 6-103  Notches on the lateral aspects of the radial metaphyses in a 6-year-old girl. Such notches are filled in by further growth and disappear as the child matures (see Fig. 6-104).

The Upper Extremity  |  THE FOREARM

395

PART 1  |  CHAPTER 6



FIGURE 6-104  This film illustrates the mechanism by which the notches seen in Figure 6-103 are obliterated. The fossa fills in by overgrowth of the epiphysis of the radial head. This is the same mechanism seen for completion of growth of the tibial tubercle. (Ref: McCarthy SM, Ogden JA: Radiology of postnatal skeletal development. VI: Elbow joint, proximal radius and ulna. Skeletal Radiol 9:17, 1982.)

FIGURE 6-105  Small cleft that might be mistaken for fracture in the medial aspect of the proximal radial metaphysis. There was no history of trauma.

FIGURE 6-106  A small spur arising from the radial head.

396

The Upper Extremity  |  THE FOREARM

FIGURE 6-107  Accessory ossicle at the tip of the coronoid process. Old avulsion injuries may also manifest as ossicles of this type. (Ref: Glajchen N, et al: Avulsion fracture of the sublime tubercle of the ulna: A newly recognized injury in the throwing athlete. AJR Am J Roentgenol 170:627, 1998.)

FIGURE 6-108  Accessory ossification centers for the tip of the coronoid process that could be mistaken for a fracture.

FIGURE 6-109  Persistent ossification center of the coronoid process of the ulna simulating a fracture.

The Upper Extremity  |  THE FOREARM

397

PART 1  |  CHAPTER 6



FIGURE 6-110  Examples of fossae in the ulna that represent the insertion point of the annular ligament. They should not be confused with a pathologic process. (Ref: Schoneich R: Tuberositas radii varietat “Bandgruber.” Rofo 149:675, 1988.)

FIGURE 6-111  Unusually long coronoid process of the ulna, possibly related to stress.

FIGURE 6-112  Oblique radiolucent clefts in proximal radial metaphyses in a young child. These oblique clefts are common findings adjacent to the epiphyseal lines in young children and should not be mistaken for metaphyseal fractures. (Ref: Silberstein MJ, et al: Some vagaries of the radial head and neck. J Bone Joint Surg Am 64:1153, 1982.)

398

The Upper Extremity  |  THE FOREARM

FIGURE 6-113  The radial tuberosity manifests as a radiolucency and might be mistaken in both projections for an area of bone destruction.

FIGURE 6-114  A radial tuberosity in a 4-year-old boy simulating a focal destructive lesion only in the lateral projection.

The Upper Extremity  |  THE FOREARM

399

PART 1  |  CHAPTER 6



FIGURE 6-115  The interosseous ridges of the radius and ulna often cast shadows that may be mistaken for periostitis.

FIGURE 6-116  Physiologic “periostitis” of the newborn in a 21⁄ 2-month-old infant. This is not seen before age 1 month, is symmetric in distribution although not necessarily concentric, and may be seen in only one view.  (Ref: Shopfner CE: Periosteal bone growth in normal infants: A preliminary report. Am J Roentgenol Radium Ther Nucl Med 97:154, 1966.)

400

The Upper Extremity  |  THE FOREARM

FIGURE 6-117  The nutrient channel of the radius.

FIGURE 6-118  Normal undulations in contour of the radii of the newborn. These disappear with age.

FIGURE 6-119  Cortical tunneling of the distal ulna may be seen in infants and older children and is of no clinical significance. (Ref: Weiss C: Normal roentgen variant: Cortical tunneling of the distal ulna. Radiology 136:294, 1980.)

The Upper Extremity  |  THE FOREARM

401

PART 1  |  CHAPTER 6



FIGURE 6-120  A, B, Bilateral physiologic bowing of both bones of the forearm seen in a patient with ulna minus variation.

A

B

The Distal Portion of the Forearm

FIGURE 6-121  Small normal metaphyseal spurs of the distal radius in a healthy 1-year-old girl. (Ref: Kleinman PK, et al: Normal metaphyseal radiologic variant, not to be confused with findings of infant abuse. AJR Am J Roentgenol 156:781, 1991.)

FIGURE 6-122  Dense zones of provisional calcification not shown elsewhere. This is a normal phenomenon about the age of 2 years.

402

The Upper Extremity  |  THE FOREARM

FIGURE 6-123  Normal metaphyseal irregularities of the radius in a 14-year-old boy. These changes were no longer present 1 year later.

FIGURE 6-124  Two examples of thin flanges of bone simulating periostitis of the distal radius.

FIGURE 6-125  Examples of cortical irregularities at insertion of interosseous membrane simulating periostitis.

The Upper Extremity  |  THE FOREARM

403

PART 1  |  CHAPTER 6



FIGURE 6-126  Developmental fossa in distal ulna.

FIGURE 6-127  Ulna plus variation with wide separation of the distal ulna and radius.

FIGURE 6-128  Unusually long ulna (ulna plus variant), which may be mistaken for a dislocation of the distal radioulnar joint if the bilateral symmetry is not noted.

404

The Upper Extremity  |  THE FOREARM

FIGURE 6-129  Apparent dorsal dislocation of the ulna caused by curvature of the shaft, which can be seen in the lateral projection.

FIGURE 6-130  Normal spurlike projections of the epiphysis at the epiphyseal line simulating avulsion injuries. (Ref: Keats TE, Harrison RB: The epiphyseal spur. Skeletal Radiol 5:175, 1980.)

FIGURE 6-131  Two examples of epiphyseal spurs on medial and lateral aspects of the distal radius.

The Upper Extremity  |  THE FOREARM

405

PART 1  |  CHAPTER 6



FIGURE 6-132  Residual epiphyseal spur after closure of the epiphyseal plate in a 20-year-old man.

FIGURE 6-133  Closed epiphyseal spur at the edge of the closed physis mistaken for an avulsion fracture.

FIGURE 6-134  Large residual epiphyseal spur that might be mistaken for an avulsion.

FIGURE 6-135  Remnants of the epiphyseal line in a 20-year-old man.

406

The Upper Extremity  |  THE FOREARM

FIGURE 6-136  Small spicules in the epiphyseal cartilage of the ulna in a healthy 11-year-old girl. This is a normal finding of no significance.

FIGURE 6-137  Spicule in the epiphyseal cartilage of the radius of a 12-year-old boy.

A

B FIGURE 6-138  Spicules in the epiphyseal cartilage of the ulna with long streaks in the shaft in a healthy 12-year-old boy.

FIGURE 6-139  Normal extension of the epiphysis into the physis similar to Krump’s hump in the ankle.

The Upper Extremity  |  THE FOREARM

407

PART 1  |  CHAPTER 6



FIGURE 6-140  Normal extension of the metaphysis into the physis of the ulna.

FIGURE 6-141  Discordant closure of the physis of the radius and ulna is normal and therefore not useful in diagnosing Salter I fracture.

FIGURE 6-142  Deep symmetric fossae below the radioulnar joint simulating erosions.

408

The Upper Extremity  |  THE FOREARM

FIGURE 6-143  Simulated fracture of the radial epiphysis produced by superimposed projection of the epiphyseal plate at different levels.

FIGURE 6-144  Examples of cleft distal ulnar epiphyses.

FIGURE 6-145  Unilateral cleft ulnar styloid epiphysis in a 14-year-old boy.

The Upper Extremity  |  THE FOREARM

409

PART 1  |  CHAPTER 6



FIGURE 6-146  Cleft distal radial epiphysis seen only in the oblique projection. Any epiphysis or apophysis may develop from multiple centers. (Ref: Harrison RB, Keats TE: Epiphyseal clefts. Skeletal Radiol 5:23, 1980.)

FIGURE 6-147  Separate ossification centers for the radial styloid process, which may persist into adult life and be mistaken for fracture.

410

The Upper Extremity  |  THE FOREARM

FIGURE 6-148  Accessory ossicle of the end of the ulnar styloid, which should not be mistaken for a fracture.

FIGURE 6-149  Unusual lucencies of the medial aspects of the ulnar epiphyses.

The Upper Extremity  |  THE FOREARM

411

PART 1  |  CHAPTER 6



A B FIGURE 6-150  Two examples of ununited ossification centers of the ulnar styloid process. A, A 15-year-old patient. B, A 27-year-old patient.

FIGURE 6-151  Accessory ossicles at the ulnar styloid that articulate with the styloid process.

412

The Upper Extremity  |  THE FOREARM

FIGURE 6-152  Unusual length and configuration of the ulnar styloid processes.

FIGURE 6-153  Not all styloid ossicles are developmental; some may be traumatic in origin. Left, Fracture of the ulnar styloid in a 16-year-old patient. Right, At age 26 years, the fracture fragment has evolved into an ossicle.

FIGURE 6-154  Unusual configuration of the ulnar styloids.

The Upper Extremity  |  THE FOREARM

413

PART 1  |  CHAPTER 6



FIGURE 6-155  Huge ulnar styloid processes.

FIGURE 6-156  Unusually long ulnar styloid process that results in stylocarpal impaction.

FIGURE 6-157  Ring shadow on the ulnar styloid. This lesion is similar to other entities seen elsewhere in the wrist and hands that are probably fibrous in nature. They do not appear to be of clinical significance (see Figs. 6-240 and 6-277).

414

The Upper Extremity  |  THE HAND

THE HAND The Carpals THE ACCESSORY OSSICLES

FIGURE 6-158  The accessory ossicles of the hand (after Kohler). The sesamoid bones are indicated by shaded circles. (Ref: Kohler A, Zimmer EA: Borderlands of the Normal and Early Pathologic Findings in Skeletal Roentgenology, 4th ed. New York, Thieme, 1993.) The MR image appearances of these ossicles and other variants of the wrist are described by Timins. (Ref: Timins ME: Osseous anatomic variants of the wrist: Findings on MR Imaging. AJR Am J Roentgenol 173:339, 1999.) 1. Epitrapezium 2. Calcification (bursa, flexor carpi radialis) 3. Paratrapezium (petrapezium) 4. Trapezium secundarium 5. Trapezoides secundarium 6. Os styloideum 7. Ossiculum gruberi 8. Capitatum secundarium 9. Os hamuli proprium 10. Os vesalianum 11. Os ulnare externum (calcified bursa or tendon) 12. Os radiale externum 13. Fissure of traumatic origin 14. Persisting ossification center of the radial styloid process 15. Intercalary bone between the navicular and the radius (paranavicular) 16. Os carpi centrale 17. Hypolunatum 18. Epilunatum 19. Accessory bone between the lunate and the triangular bone 20. Epipyramis 21. So-called “os triangulare” 22. Persisting center of the ulnar styloid 23. Small ossicle at the level of the radioulnar joint 25. Avulsion from the triangular bone; no accessory ossicle 26. Tendon or bursal calcification 27. Calcification of the pisiform

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PART 1  |  CHAPTER 6



FIGURE 6-159  Accessory ossicle at the radial styloid process representing a persistent ossification center.

FIGURE 6-160  The os styloideum. This ossicle lies between the capitate and the bases of the second and third metacarpals. It produces a small immovable protuberance on the dorsum of the hand and may give rise to symptoms. (Refs: Bassoe E, Bassoe H: The styloid bone and carpe bossu disease. Am J Roentgenol Radium Ther Nucl Med 74:886, 1955; and Conway WF, et al: The carpal boss: An overview of radiographic evaluation. Radiology 156:29, 1985.)

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FIGURE 6-161  Two additional examples of the os styloideum.

FIGURE 6-163  The os epitriquetrum (os epipyramis). This ossicle, which is located on the dorsal and radial edge of the triquetrum, varies in size.

FIGURE 6-162  In the external oblique projection of the wrist, the dorsal aspect of the capitate is thrown into relief and simulates a fracture or an os styloideum.

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417

PART 1  |  CHAPTER 6



FIGURE 6-164  The os epilunatum.

FIGURE 6-165  Large os epilunatum.

FIGURE 6-166  The os triangulare.

FIGURE 6-167  Large os triangulare. (see Fig. 6-168).

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FIGURE 6-168  Large bilateral os triangulare.

FIGURE 6-169  Accessory ossicle between the lunate and triquetrum.

FIGURE 6-170  The os hamuli proprium.

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PART 1  |  CHAPTER 6



FIGURE 6-171  Examples of the os vesalianum.

FIGURE 6-172  Accessory centers of ossification for the tuberosity of the navicular.

FIGURE 6-173  Calcified nodules, probably in the abductor pollicis longus tendon.

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FIGURE 6-174  The os carpi centrale.

FIGURE 6-175  The os paratrapezium.

FIGURE 6-176  The os trapezium secundarium.

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PART 1  |  CHAPTER 6



FIGURE 6-177  Two examples of the trapezium secundarium.

FIGURE 6-178  Accessory pisiform.

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THE CARPALS IN GENERAL

FIGURE 6-179  Normal ossification centers do not always develop symmetrically, as evidenced in this 23-month-old child.

FIGURE 6-180  Accelerated bone age associated with excessive obesity. This 2-year-old boy has a bone age approximately three times his chronologic age. (Ref: Silverman FN, Kuhn J: Caffey’s Pediatric X-Ray Diagnosis, 9th ed. St. Louis, Mosby, 1993.)

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PART 1  |  CHAPTER 6



A

B

FIGURE 6-181  A, B, Triangulation of the carpus caused by inclination of the articular surface of the radius. This appearance may simulate Madelung’s deformity, but the lateral projection shows normal position of the ulna, unlike that of Madelung’s deformity.

FIGURE 6-182  Multiple carpal coalitions involving the lunate and triquetrum, the capitate and hamate, and the trapezoid and trapezium.

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FIGURE 6-183  Bilateral coalition between the capitate and hamate.

THE CAPITATE AND LUNATE BONES

FIGURE 6-184  Bipartite lunate in a young child.

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425

PART 1  |  CHAPTER 6



FIGURE 6-185  Abortive coalition between the lunate and triquetrum.

FIGURE 6-186  Bilateral hypoplastic lunates discovered as incidental findings after fracture of right wrist.

426

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FIGURE 6-187  Dorsal flexion of the wrist in lateral projection can simulate dorsal instability of the lunate. Palmar flexion can similarly simulate volar instability of the lunate.

A

B

FIGURE 6-188  A, B, Unimportant bilateral volar tilt of the lunates in a 10-year-old boy. The right wrist was injured. Note that the lunate is tilted in a volar direction despite the fact that the wrist is extended (B).

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427

PART 1  |  CHAPTER 6



FIGURE 6-190  Huge os epilunatum. FIGURE 6-189  Small os epilunatum.

FIGURE 6-191  Two examples of asymptomatic and clinically unimportant bone islands in the capitate (m). A bone island also appears in the lunate in the first example (m 66).

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FIGURE 6-193  Lucent cleft in the capitate simulating a fracture. FIGURE 6-192  Vascular foramina in the capitate bone (m). A similar foramen is seen in the lunate (m 66).

FIGURE 6-194  Deep fossa in the radial side of the capitate. The os carpi centrale may develop in this fossa (see Fig. 6-174). FIGURE 6-195  The capitate fossa may simulate an erosion.

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PART 1  |  CHAPTER 6



FIGURE 6-196  The os carpi centrale present bilaterally in a child.

FIGURE 6-197  A large os carpi centrale in an adult. (Ref: Gerscovich EO, Greenspan A: Case report 598: Os centrale carpi. Skeletal Radiol 19:143, 1990.)

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FIGURE 6-198  The joint between the capitate and hamate may be poorly visualized in normal individuals and should not be mistaken for the changes of an inflammatory arthritis.

FIGURE 6-199  Left, Apparent loss of the joint space between the capitate and hamate produced by inability of the patient to flatten the hand. Note similar overlap of scaphoid and lunate. Right, Improved positioning shows normal relationships.

FIGURE 6-200  Congenital fusion of the capitate and hamate. Carpal fusions may occur as isolated anomalies or may be associated with congenital malformation syndromes. The isolated fusions usually involve bones of the same row, such as triquetrum–lunate, capitate–hamate, or trapezium–trapezoid, whereas syndrome-related fusions often go across rows, such as trapezium–scaphoid. (Ref: Poznanski AJ: The hand in Radiologic Diagnosis, 2nd ed. Philadelphia, WB Saunders, 1984.)

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PART 1  |  CHAPTER 6



FIGURE 6-201  Relationships of capitate to lunate vary, depending on degree of flexion or extension of the hand.

FIGURE 6-203  The os styloideum (see Figs. 6-160 and 6-161).

FIGURE 6-202  Congenital fusion of the lunate and triquetrum. Patients with this type of coalition may have a wide scapholunate space as a normal variation. (Ref: Metz VM, et al: Wide scapholunate space in lunotriquetral coalition: A normal variant? Radiology 188:557, 1993.)

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FIGURE 6-204  Bilateral congenital fusions of the capitate, hamate, trapezoid, and trapezium.

THE HAMATE BONE

FIGURE 6-205  Elongated unciform process of the hamate, the origin of the flexor digiti quinti muscle (m). Note also the cystlike shadow produced by the base of the unciform process (m 66).

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433

PART 1  |  CHAPTER 6



FIGURE 6-206  Elongated unciform process of the hamate misdiagnosed as a fracture (m). The cleft of the base of the fifth metacarpal is normal (m 6).

FIGURE 6-207  The hamulus of the hamate in lateral projection. This process should not be mistaken for a trapezium secundarium.

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FIGURE 6-208  Two examples of the os hamuli proprium. The unciform process of the hamate may ossify independently, giving the impression of an accessory bone or a fracture. (Ref: Kohler A, Zimmer EA: Borderlands of the Normal and Early Pathologic Findings in Skeletal Roentgenology, 4th ed. New York, Thieme, 1993.)

A

B

C FIGURE 6-209  The os hamuli proprium. A, Normal wrist. B, Wrist with separate unciform process. Note absence of ring shadow. C, Os hamuli proprium seen in carpal tunnel projection. Rarely, the hook of the hamate may be congenitally absent. (Ref: Seeger LL, et al: Case Report 464: Bilateral congenital absence of the hook of the hamate. Skeletal Radiol 17:85, 1988.)

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PART 1  |  CHAPTER 6



FIGURE 6-210  Bilateral os hamuli proprium. Note the absence of ring shadows in the hamates in the frontal projections.

THE TRAPEZIUM AND TRAPEZOID BONES

FIGURE 6-211  Hypoplasia of the trapezoid in a 13-year-old boy.

FIGURE 6-212  Irregularity of the radial aspect of the trapezium simulating a fracture.

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FIGURE 6-214  Osseous process arising from the trapezium (see Fig. 6-215).

FIGURE 6-213  The os paratrapezium.

A

B

C

FIGURE 6-215  A through C, Attempted formation of an accessory metacarpal, seen best in B, arising from the trapezium.

FIGURE 6-216  Distal prolongation of the medial facet of the trapezium.

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437

PART 1  |  CHAPTER 6



A

B FIGURE 6-217  A, B, The trapezium secondarium.

THE NAVICULAR BONE

FIGURE 6-218  Unilateral development of the navicular from multiple foci in an 11-year-old boy.

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FIGURE 6-219  Left, Accessory ossification center for the navicular in a 10-year-old boy. Right, Five months later, there is partial incorporation of the center.

FIGURE 6-220  Congenital fusion of the navicular and trapezium. Such fusions are not uncommon and usually are of no significance. (Refs: O’Rahilly R: Survey of carpal and tarsal anomalies. J Bone Joint Surg Am 35:626, 1953; Poznanski AJ: The Hand in Radiologic Diagnosis, 2nd ed. Philadelphia, WB Saunders, 1984.)

FIGURE 6-221  Congenital fusion between the scaphoid and trapezium and trapezoid. The lunate is undergoing aseptic necrosis.

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439

PART 1  |  CHAPTER 6



FIGURE 6-222  Bilateral bipartite navicular bones. (Ref: Waugh RL, Sullivan RF: Anomalies of the carpus: With particular reference to the bipartite scaphoid (navicular). J Bone Joint Surg Am 32:682, 1950.)

FIGURE 6-223  Bilateral bipartite navicular bone with aseptic necrosis of the proximal portion on the right (m).

FIGURE 6-224  Incomplete cleft simulating a fracture in the navicular in a 10-year-old girl.

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A

B

FIGURE 6-225  A, Simulated fracture of the navicular caused by trabecular pattern. B, Navicular view shows no fracture.

FIGURE 6-226  Simulated fracture of the navicular caused by trabecular pattern. Left, PA view. Right, Magnification view.

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441

PART 1  |  CHAPTER 6



FIGURE 6-227  Left, Simulated fracture of the navicular caused by trabeculation. Right, Navicular view shows no fracture but defines the trabecular nature of the pseudofracture.

FIGURE 6-228  Developmental cleft on the radial border of the navicular.

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FIGURE 6-229  Normal undulations on the radial border of the navicular.

FIGURE 6-230  Simulated cysts of the navicular produced by trabecular pattern. Navicular views showed no abnormality.

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443

PART 1  |  CHAPTER 6



A

B

FIGURE 6-231  A, Simulated rotary subluxation of the navicular produced by filming with the wrist in radial deviation. B, Normal appearance of navicular with ulnar deviation.

A

E

C

B

F

G

D

H

FIGURE 6-232  Voluntary bilateral painless subluxation of the naviculars in a 27-year-old man. A through D, Both wrists at rest. E through H, Both wrists with navicular subluxed at will.

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The Upper Extremity  |  THE HAND

A

B

FIGURE 6-233  The interval between the navicular and the lunate is not always a reliable indication of rotary subluxation of the navicular, because its width depends on the position of the thumb. Note the change in interval between A and B.

A

B

FIGURE 6-234  A, The navicular-lunate interval is normally wide in children and narrows with subsequent growth. B, Note that the intervals close with ulnar deviation of the wrists.

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445

PART 1  |  CHAPTER 6



A

B

FIGURE 6-235  A, The navicular–lunate interval in normal individuals may be quite wide, and a wide interval is not an indication of traumatic dissociation in itself. B, Film made in ulnar deviation shows normal appearance of the navicular and decrease in the navicular–lunate interval.

FIGURE 6-236  Wide navicular lunate interval in a 14-year-old boy. This appearance may be secondary to underdevelopment of the lunate, or to underdevelopment of the navicular, as in this case.

446

The Upper Extremity  |  THE HAND

A

B

C FIGURE 6-237  Unusual configuration of the scaphoid (A and B), which simulates a fracture in frontal projection (C).

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447

THE TRIQUETRUM BONE

A

B

FIGURE 6-238  A, B, Two examples of congenital fusion of the lunate and triquetrum, a relatively common site of fusion. In childhood, the fissure between the incompletely fused bones should not be mistaken for a fracture (B). (Refs: Carlson DH: Coalition of the carpal bones. Skeletal Radiol 7:125, 1981; Resnik CS, et al: Incomplete carpal coalition. AJR Am J Roentgenol 147:301, 1986.)

FIGURE 6-239  Incomplete coalition of the lunate and triquetrum bones.

PART 1  |  CHAPTER 6



448

The Upper Extremity  |  THE HAND

FIGURE 6-240  Ring lesions in the triquetrum bone. These lesions are probably fibrous and are seen elsewhere in the hand and wrist. They are apparently of no clinical significance and should be distinguished from traumatic cyst caused by occupational trauma.

A

B

FIGURE 6-241  Unusual appearance of the triquetrum bones bilaterally. A, Left wrist with spurlike projection. B, Right wrist with ossicle resembling an avulsion fracture.

The Upper Extremity  |  THE HAND

449

PART 1  |  CHAPTER 6



FIGURE 6-242  Accessory osseous element between the lunate and triquetrum.

FIGURE 6-243  Unusual configuration of the trapezium.

THE PISIFORM BONE

FIGURE 6-244  Normal irregularity of the pisiform in an 11-year-old boy. This irregularity is seen only in the lateral projection.

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The Upper Extremity  |  THE HAND

FIGURE 6-245  Developmental irregularity of the pisiform simulating a fracture in an 11-year-old boy. FIGURE 6-246  Multicentric pisiform in a young child.

FIGURE 6-247  Multicentric pisiform in a 10-year-old girl.

The Upper Extremity  |  THE HAND

451

PART 1  |  CHAPTER 6



FIGURE 6-248  Bilateral irregularities in development of the pisiforms in a 12-year-old boy.

B

A FIGURE 6-249  Variations in the pisiform bone. A, Normal but very large pisiform bone. B, Bipartite pisiform bones.

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The Upper Extremity  |  THE HAND

FIGURE 6-251  Unusually low position of the pisiform in a 12-year-old boy.

FIGURE 6-250  Multicentric pisiform in an adult.

FIGURE 6-252  Bipartite pisiform.

The Upper Extremity  |  THE HAND

453

PART 1  |  CHAPTER 6



FIGURE 6-254  The exostosis-like process of the pisiform in the tunnel view. FIGURE 6-253  Exostosis-like process on the pisiform, a variation in development.

A

B FIGURE 6-255  A, B, A large exostosis of the pisiform that is fused to the hamate.

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454

A

B

FIGURE 6-256  A, B, Congenital fusion of the triquetrum and pisiform bones with a pseudarthrosis between the pisiform and the hamate.

The Metacarpals

A

B

FIGURE 6-257  Two examples of accessory ossification centers at the bases of the metacarpals in a 3-year-old child (A) and a 4-year-old child (B). This finding is usually of no significance. (Ref: Ogden JA, et al: Ossification and pseudoepiphysis formation in the “nonepiphyseal” end of bones of the hands and feet. Skeletal Radiol 23:3, 1994.)

The Upper Extremity  |  THE HAND

455

PART 1  |  CHAPTER 6



FIGURE 6-258  Striking clarity of the carpal-metacarpal joints in a 13-year-old boy simulating dislocation of the bases of the metacarpals.

FIGURE 6-259  Accessory ossification centers at the distal end of the first metacarpal (m) and at the base of the second metacarpal (m 6) in a 13-year-old boy.

FIGURE 6-260  Remnants of closed secondary ossification centers in a 13-year-old boy. FIGURE 6-261  The clefts at the ulnar side of the base of the fifth metacarpal are particularly prone to misinterpretation as fractures.

456

The Upper Extremity  |  THE HAND

FIGURE 6-262  Developmental knoblike protuberance at the base of the fifth metacarpal.

FIGURE 6-263  Clefts at the bases of the metacarpals may simulate fractures.

The Upper Extremity  |  THE HAND

457

PART 1  |  CHAPTER 6



FIGURE 6-264  Fossa at the base of the fifth metacarpal may suggest abnormality.

FIGURE 6-265  Normal shadows at the bases of the metacarpals (m), produced by overlapping shadows of the osseous structures, that may be mistaken for fractures. Note also the normal fossa at the base of the fifth metacarpal (m 6).

FIGURE 6-267  Bulges in the cortices at the bases of the fourth and fifth metacarpals.

FIGURE 6-266  The fifth metacarpal may be broader than the others and may simulate abnormality.

458

The Upper Extremity  |  THE HAND

FIGURE 6-269  Normal lucency in the base of the second metacarpal simulating a cystlike lesion.

FIGURE 6-268  Overlapping shadows of the bases of the second and third metacarpals that simulate fracture.

FIGURE 6-270  Another example of the cystlike lesion shown in Figure 6-269.

FIGURE 6-271  Accessory ossification center at the distal end of the first metacarpal simulating a fracture.

The Upper Extremity  |  THE HAND

459

PART 1  |  CHAPTER 6



FIGURE 6-272  Two examples of accessory ossification centers at the distal end of the first metacarpal with spur at its medial margin. The epiphyseal spur is a normal variation.

FIGURE 6-274  Spurring of the margins of ossification centers for the heads of the metacarpals in a 13-year-old boy. These spurs, transient events in the development of the epiphysis, are additional examples of the epiphyseal spur. (Ref: Keats TE, Harrison RB: The epiphyseal spur. Skeletal Radiol 5:175, 1980.)

FIGURE 6-273  Closing accessory ossification center at the distal end of the first metacarpal in a 14-year-old boy.

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The Upper Extremity  |  THE HAND

FIGURE 6-275  Prominent developmental spurlike protuberances at the radial sides of the distal metaphyses of the metacarpals.

FIGURE 6-276  An example of a spurlike protuberance at the head of the fifth metacarpal, “the lesser knob of Keats” (see Fig. 6-290).

FIGURE 6-277  Ring lesions in the heads of the metacarpals. These are probably fibrous in nature and are apparently of no clinical significance (see Fig. 6-240).

The Upper Extremity  |  THE HAND

461

PART 1  |  CHAPTER 6



A

B

FIGURE 6-278  A, B, Normal exaggeration of the pitlike depression in the head of the fifth metacarpal (m). This does not represent an erosion. The more usual appearance is seen in the head of the fourth metacarpal in B (m 66).

FIGURE 6-279  Developmental spurlike projection at the radial side of the base of the second metacarpal.

Figure 6-280  Osseous excrescence at the base of the third metacarpal.

462

The Upper Extremity  |  THE HAND

A

B

FIGURE 6-281  Normal relationships between the base of the first metacarpal and trapezium. This relationship is at times mistaken for a subluxation. A, Abduction of the thumb. B, Adduction of the thumb. (Ref: Lasserre C, et al: Osteoarthritis of the trapezio-metacarpal joint. J Bone Joint Surg Br 31:534, 1949.)

FIGURE 6-282  Two examples of the trapezium secundarium.

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463

PART 1  |  CHAPTER 6



A

C

B

FIGURE 6-283  The metacarpal sign. A tangent drawn through the distal ends of the fourth and fifth metacarpals normally does not intersect the head of the third metacarpal. A, Normal. B, Borderline. C, Positive. A positive metacarpal sign is seen in some forms of gonadal dysgenesis but may also occur as a normal variant; its usefulness is therefore limited. (Ref: Bloom RA: The metacarpal sign. Br J Radiol 43:133, 1970.)

FIGURE 6-284  Short fourth metacarpals with positive metacarpal sign as a familial trait in a normal individual. Note the short middle phalanges of the fifth fingers, also a familial trait.

A

B FIGURE 6-285  A, B, Bilateral short fifth metacarpals, usually a normal familial trait.

464

The Upper Extremity  |  THE HAND

FIGURE 6-286  Osseous flanges on the metacarpal should not be mistaken for periostitis.

FIGURE 6-287  Note the relationships of the proximal phalanx and the metacarpal of the fifth finger with hyperextension in the oblique projection. This finding should not be interpreted as a subluxation.

FIGURE 6-288  Examples of stenosis of the medullary cavities of the metacarpals, a finding of no clinical significance.

The Upper Extremity  |  THE HAND

465

PART 1  |  CHAPTER 6



FIGURE 6-289  Normal palmar-directed position of the head of the fifth metacarpal, not to be mistaken for displacement caused by trauma.

A

B

FIGURE 6-290  A, B, A knoblike developmental variation in the head of the first metacarpal that may be confused with a sessile osteochondroma. No anatomic structure can be implicated in the development of this knob. It may be seen on both medial and lateral aspects of bone. In jest, we have named it “the great knob of Keats.”

466

The Upper Extremity  |  THE HAND

A

B

C

FIGURE 6-291  A through C, Variations of the “great knob”. A, Knob simulates an osteochondroma. B, The knob with an associated ossicle. C, Bilateral knobs.

FIGURE 6-292  A similar entity at the head of the second metacarpal.

The Upper Extremity  |  THE HAND

The Sesamoid Bones

FIGURE 6-293  Diagram of all the recognized sesamoid bones of the hand (after Degen).

FIGURE 6-294  Sesamoid bone at the interphalangeal joint of the thumb.

467

PART 1  |  CHAPTER 6



The Upper Extremity  |  THE HAND

468

FIGURE 6-295  Unusual sesamoid in dorsal aspect of the interphalangeal joint of the thumb. FIGURE 6-296  Solitary sesamoid bone at the head of the fourth metacarpal.

A

B FIGURE 6-297  Sesamoid bones at each metacarpal head in frontal (A) and oblique (B) projections.

The Upper Extremity  |  THE HAND

469

PART 1  |  CHAPTER 6



FIGURE 6-298  Ossicle at the base of the proximal phalanx of the index finger, possibly a sesamoid.

FIGURE 6-299  Unusual sesamoids at the heads of the third and fourth metacarpals.

The Fingers

FIGURE 6-300  Left, Supernumerary phalanges in the distal digits of an otherwise healthy 10-month-old child. Right, Film of same patient at 19 years of age showing closing of the accessory centers of ossification. (Courtesy Dr. N. Warn Courtney.)

470

The Upper Extremity  |  THE HAND

A

B

FIGURE 6-301  A, Cleft epiphysis of proximal phalanx of the thumb seen in the oblique projection. B, Cleft is not visible in frontal projection. (Ref: Harrison RB, Keats TE: Epiphyseal clefts. Skeletal Radiol 5:23, 1980.)

FIGURE 6-302  Accessory centers of ossification of the epiphyses of the proximal phalanges simulating avulsion injuries.

The Upper Extremity  |  THE HAND

471

PART 1  |  CHAPTER 6



FIGURE 6-304  Mach effect of metaphysis superimposing on epiphysis, suggesting a fracture.

FIGURE 6-303  Small notch in base of proximal phalanx of thumb that should not to be mistaken for an erosion.

FIGURE 6-305  Attempt to form an accessory ossification center at the head of the proximal phalanx of the fourth finger in an 11-year-old boy. This finding might be mistaken for a fracture.

FIGURE 6-306  Osseous element in epiphyseal line at the base of the proximal phalanx of the fourth finger in a child (see Fig. 6-329).

472

The Upper Extremity  |  THE HAND

B

A FIGURE 6-307  A, B, Pseudoepiphyses in the bends of the middle phalanges in children.

The Upper Extremity  |  THE HAND

473

PART 1  |  CHAPTER 6



FIGURE 6-309  Normal lucent fissures in the epiphyses in a 14-year-old boy that may be mistaken for fractures.

FIGURE 6-308  Attempt to form an accessory ossification center at the distal end of the proximal phalanx of the thumb in a 10-year-old boy (m). Note similar process at the end of the metacarpal (m 6 ).

A

B FIGURE 6-310  The epiphyseal line may simulate a fracture in the oblique projection. A, Frontal projection. B, Oblique projection.

474

The Upper Extremity  |  THE HAND

FIGURE 6-311  The nutrient foramen of the proximal phalanx.

FIGURE 6-312  Two examples of a small spurlike excrescence in the cortex of the proximal phalanx of the thumb that probably represent the insertion of the extensor pollicis brevis tendon.

FIGURE 6-313  Left and center, Small, incidentally found excrescence at the base of the proximal phalanx of the fourth finger. Right, Normal tuberosities of the bases of the phalanges, not to be mistaken for torus fractures.

The Upper Extremity  |  THE HAND

475

PART 1  |  CHAPTER 6



FIGURE 6-314  Small notches in the bases of the proximal phalanges should not be mistaken for the erosions of inflammatory arthritis, which should involve the heads of the metacarpals initially. (Ref: Stelling CB, et al: Irregularities at the base of the proximal phalanges: A false indicator of early rheumatoid arthritis. AJR Am J Roentgenol 138:695, 1982.)

FIGURE 6-315  Normal ridges and projections of the proximal phalanx caused by tendon sheath attachments, which may simulate periostitis or calcifying hematoma.

476

The Upper Extremity  |  THE HAND

FIGURE 6-317  Normal irregularities of the palmar aspects of the proximal and middle phalanges of the index finger.

FIGURE 6-316  Hypoplastic middle phalanx of short left finger with oblique physis simulating a fracture.

FIGURE 6-318  Three examples of triphalangeal thumbs. (Ref: Theander G, Carstanm N: Triphalangism and pseudotriphalangism of the thumb in children. Acta Radiol Diagn 20:223, 1979.)

The Upper Extremity  |  THE HAND

477

PART 1  |  CHAPTER 6



FIGURE 6-320  Osteosclerosis of the middle phalanx of the fifth finger.

FIGURE 6-319  Exaggeration of normal irregularity of the head of the proximal phalanx of the third finger, not an exostosis.

FIGURE 6-321  Nutrient foramina at the heads of the proximal phalanges. Left, 2-year-old child. Right, Adult.

478

The Upper Extremity  |  THE HAND

B

A FIGURE 6-322  A, Cortical thinning of the lateral aspect of the shaft of the distal end of the proximal phalanx simulating bone destruction. This is seen in the presence of osteoporosis. B, Similar appearance in other fingers.

FIGURE 6-323  Short middle phalanges of the fifth fingers are associated with malformation syndromes but may also be a normal familial trait, as in this 18-year-old woman.

The Upper Extremity  |  THE HAND

479

PART 1  |  CHAPTER 6



FIGURE 6-324  Anomalous development of the first metacarpals and the middle phalanges in a healthy 3-year-old child, representing a familial trait.

FIGURE 6-325  Normal relationships of the middle and distal phalanges of the thumb in a 9-year-old boy. Note the wedged configuration of the epiphysis at the base of the distal phalanx.

FIGURE 6-326  Ivory epiphyses in the hands of children may occur as isolated events without clinical significance. They are more common in children with delayed maturation. (Refs: Kuhns LR, et al: Ivory epiphyses of the hands. Radiology 109:643, 1973; Van der Laan JG, Thijn CJ: Ivory and dense epiphyses of the hand: Thiemann disease in three sisters. Skeletal Radiol 15:117, 1986.)

480

The Upper Extremity  |  THE HAND

FIGURE 6-327  Unusual clinodactyly of the fifth finger in an otherwise normal 14-year-old boy.

FIGURE 6-328  Unusually large epiphysis of the base of the thumb.

The Upper Extremity  |  THE HAND

481

PART 1  |  CHAPTER 6



FIGURE 6-329  Horizontal fissure adjacent to the epiphyseal plate of the distal phalanx of the thumb in a 9-year-old child, which should not be mistaken for a fracture.

FIGURE 6-330  Normal configurations of the terminal phalanges that should not be mistaken for the effects of trauma.

482

The Upper Extremity  |  THE HAND

A

D

B

E

C

F

FIGURE 6-331  A, B, Fossa in the base of the distal phalanx of the thumb may simulate a destructive lesion. C, Lateral projection shows only the fossa. D through F, Similar appearance is seen on the opposite side.

FIGURE 6-332  Attempted bifid distal phalanx.

FIGURE 6-333  Bifid terminal digit of the thumb.

The Upper Extremity  |  THE HAND

483

PART 1  |  CHAPTER 6



FIGURE 6-334  Duplication of the terminal phalanges of the thumbs.

FIGURE 6-336  Sclerosis of the terminal phalanges is seen in the collagenvascular diseases but may also occur in normal individuals, usually in women older than 40 years. (Ref: Goodman N: The significance of terminal phalangeal osteosclerosis. Radiology 89:709, 1967.) The sclerosis begins early in adult life and regresses with old age. (Ref: Fischer E: Akroostiosklerose der finger, cine normale geschlects und altersabbangige endostale reaktion. Rofo 137:384, 1982.)

FIGURE 6-335  Familial broad thumbs. Short, broad, distal phalanges of the thumbs are often seen in malformation syndromes but may also occur as normal familial traits.

FIGURE 6-337  Bilateral terminal phalangeal sclerosis with varied degrees of involvement in a 60-year-old woman.

FIGURE 6-338  Persistence of terminal phalangeal sclerosis in an 80-year-old woman.

FIGURE 6-339  Terminal phalangeal sclerosis of a single digit.

FIGURE 6-340  Normal contour of the base of the distal phalanx, which may be mistaken for a healed fracture.

CHAPTER

6

The Upper Extremity

FIGURES

THE HUMERUS The Proximal Portion of the Humerus The Distal Portion of the Humerus

6S-1 to 6S-13 6S-1 to 6S-10 6S-11 to 6S-13

THE FOREARM The Proximal Portion of the Forearm The Distal Portion of the Forearm

6S-14 to 6S-32 6S-14 to 6S-21 6S-22 to 6S-32

THE HAND The Carpals The Accessory Ossicles The Capitate and Lunate Bones The Hamate Bone The Trapezium and Trapezoid Bones The Navicular Bone The Triquetrum Bone The Pisiform The Metacarpals The Sesamoid Bones The Fingers

6S-33 6S-33 6S-33 6S-36 6S-40 6S-41 6S-44 6S-53 6S-54 6S-55 6S-60 6S-61

6S-166

to to to to

6S-68 6S-54 6S-35 6S-39

to 6S-43 to 6S-52

to 6S-59 to 6S-68



The Upper Extremity  |  THE HUMERUS 6S-167

THE HUMERUS The Proximal Portion of the Humerus

A

B FIGURE 6S-1  A, Fat outlining the subdeltoid bursa. B, Bilateral visualization of the rotator cuff because of surrounding fat in a 29-year-old man.

FIGURE 6S-2  Simulated aseptic necrosis of the humeral head in an elderly patient produced by overlapping of the shadows of the humeral head and scapula. Note variation in width of dense area with changes in position of the shoulder. This appearance is accentuated by a rotator cuff tear.

6S-168 The Upper Extremity  |  THE HUMERUS

FIGURE 6S-3  The shadows of the bicipital groove in an adult. Left, External rotation. Right, Internal rotation.

FIGURE 6S-4  The greater tuberosity en face simulating a lytic lesion.



The Upper Extremity  |  THE HUMERUS 6S-169

FIGURE 6S-5  Residua of the closing epiphyseal line in a 16-year-old boy.

FIGURE 6S-7  Unusual ossicle at the upper end of the humerus. FIGURE 6S-6  Upper humeral notch in a 13-year-old boy (m). Note also benign cortical defect (m 6) and normal glenoid irregularities (m 66).

FIGURE 6S-8  Developmental spurs in a 22-year-old woman simulating those of degenerative joint disease.

6S-170 The Upper Extremity  |  THE HUMERUS

FIGURE 6S-9  Deltoid muscle insertion that resembles periostitis. FIGURE 6S-10  The pectoralis major insertion on T1-weighted MR image.

The Distal Portion of the Humerus

FIGURE 6S-11  Developmental foramen above the medial epicondyle.



The Upper Extremity  |  THE HUMERUS 6S-171

FIGURE 6S-12  Simulated fractures produced by soft tissue folds.

A

B

FIGURE 6S-13  A, Apparent displacement of the ossification center for the capitellum as a result of poor positioning of the forearm. B, Proper positioning shows normal relationships.

6S-172 The Upper Extremity  |  THE FOREARM

THE FOREARM The Proximal Portion of the Forearm

FIGURE 6S-14  Spur at the olecranon in a 5-year-old child, probably representing modeling to receive the apophysis, which is not yet ossified.

FIGURE 6S-15  Probable bone island in the proximal portion of the ulna.

FIGURE 6S-16  Bilaterally symmetric separate nuclei of ossification for the olecranon process in a 13-year-old boy.

FIGURE 6S-17  Small cleft in the radial metaphysis in a 16-year-old girl, which should not be mistaken for a fracture.



The Upper Extremity  |  THE FOREARM 6S-173

FIGURE 6S-18  Ossification center at the tip of the coronoid process of the ulna (os cubiti anterius) in an adolescent.

FIGURE 6S-19  Ossicle at the tip of the coronoid process in a 12-year-old child. Large arrow indicates the ossification center for the medial epicondyle in lateral projection.

FIGURE 6S-20  Partially fused ossicle at tip of the coronoid process of the ulna.

6S-174 The Upper Extremity  |  THE FOREARM

FIGURE 6S-21  Tendinous calcification at the coronoid process in the origins of the flexor digitorum superficiale (m) and at the insertion of the triceps tendon (m 6). Such calcifications should not be mistaken for traumatic sequelae.

The Distal Portion of the Forearm

FIGURE 6S-22  Small irregularities of the metaphysis in a 10-year-old girl.

FIGURE 6S-23  Short ulna (ulna minus variant) with a deep articulation with the radius that resembles an erosive lesion. (Ref: Gelberman RH, et al: Ulnar variance in Kienbock’s disease. J Bone Joint Surg Am 57:674, 1975.)



The Upper Extremity  |  THE FOREARM 6S-175

FIGURE 6S-24  Ulna plus variant. Note close approximation of the ulnar styloid to the triquetrum bone. This variant may lead to ulnar impaction syndrome and injury to the triangular fibrocartilage. (Ref: Escobedo EM, et al: MR imaging of ulnar impaction. Skeletal Radiol 24:85, 1995.)

FIGURE 6S-25  Left, Misdiagnosis of dislocation of the distal radioulnar joint caused by filming with wrist slightly rotated. Right, True lateral projection shows normal relationships.

FIGURE 6S-26  Remnants of the epiphyseal line simulating a fracture in an 18-year-old man.

FIGURE 6S-27  Spicules in the epiphyseal cartilage of the ulna in a 13-year-old boy.

6S-176 The Upper Extremity  |  THE FOREARM

FIGURE 6S-28  Deep asymmetric fossa on the left.

FIGURE 6S-29  Closing distal radial epiphyseal line simulating a fracture. This situation prevails when the ulnar aspect of the distal radial epiphysis is thin, and the remnant of the epiphyseal line may be confused with an incomplete fracture. (From Teates CD: Distal radial growth plate remnant simulating fracture. Am J Roentgenol Radium Ther Nucl Med 110:578, 1970.)

FIGURE 6S-30  Unnamed ossicle in the radioulnar joint.



The Upper Extremity  |  THE FOREARM 6S-177

FIGURE 6S-31  A, B, Unusually long distal extension of the radial styloid simulates a fracture fragment in the lateral projection (B).

A

B

FIGURE 6S-32  The “vacuum” phenomenon in the wrist joint.

6S-178 The Upper Extremity  |  THE HAND

THE HAND The Carpals THE ACCESSORY OSSICLES

FIGURE 6S-33  Bilateral os triangulare. Some osseous elements in this area may represent old avulsions of the styloid process. This is not true in this illustration, which is of a normal variation. (Ref: Kohler A, Zimmer EA: Borderlands of the Normal and Early Pathologic Findings in Skeletal Roentgenology, 4th ed, New York, Thieme, 1993.)

FIGURE 6S-34  Accessory bone between the lunate and capitate bones.

FIGURE 6S-35  A, B, The trapezium secundarium.

A

B



The Upper Extremity  |  THE HAND 6S-179

THE CAPITATE AND LUNATE BONES

A

B FIGURE 6S-36  Bone island in the lunate. A, Plain film. B, Corresponding MR image.

FIGURE 6S-37  The vascular foramen of the lunate (m). A bone island is present in the navicular (m 6).

FIGURE 6S-38  Bone island in the lunate in a 14-year-old boy.

6S-180 The Upper Extremity  |  THE HAND

FIGURE 6S-39  Top left, Poorly positioned PA view misconstrued as showing fracture of the capitate as a result of overlap of the shadows of the capitate and hamate. Top right, Correct positioning shows no fracture. Bottom, Off-lateral projection of wrist shows simulated fracture of the posterior aspect of the capitate.

THE HAMATE BONE

FIGURE 6S-40  Developmental cleft in the lateral aspect of the hamate.



The Upper Extremity  |  THE HAND 6S-181

THE TRAPEZIUM AND TRAPEZOID BONES

FIGURE 6S-41  The carpal tunnel projection may produce an end-on view of the fifth metacarpal superimposed on the carpal bones, resulting in a ringlike radiolucency that should not be mistaken for a pathologic process. (Ref: Fodor J 3rd, et al: Carpal tunnel ring artifact. AJR Am J Roentgenol 144:765, 1985.)

FIGURE 6S-42  Ring lesion in the trapezium. Such lesions are fibrous in nature and are seen elsewhere in the hand and wrist. They are apparently of no clinical significance.

FIGURE 6S-43  Bilateral coalition of the trapezium and trapezoid.

6S-182 The Upper Extremity  |  THE HAND

THE NAVICULAR BONE

FIGURE 6S-44  Two views of a bipartite navicular bone (m). Note the joint space, which is visible in both projections (m 66).

A

B

C

FIGURE 6S-45  A through C, Partial division of the navicular bone simulating a fracture. These clefts are best seen on the ulnar border (A, B) but may be seen on the radial border as well (C).

FIGURE 6S-47  Trabecular pattern simulating a fracture of the navicular. FIGURE 6S-46  Simulated fracture of the navicular caused by Mach effect of underlying radial styloid.



The Upper Extremity  |  THE HAND 6S-183

FIGURE 6S-48  Simulated fracture of the navicular caused by a notch on lateral margin.

FIGURE 6S-49  Bone island in the navicular.

A

B

FIGURE 6S-50  Rotary subluxation of the navicular may be simulated by faulty positioning of the wrist at the time of filming. A, Note position of the ulnar styloid, indicating rotation of the wrist. The foreshortened configuration of the navicular is similar to the appearance of rotary subluxation. B, Correct positioning of the wrist. Navicular assumes a normal configuration. (Ref: Hudson TM, et al: Isolated rotary subluxation of the carpal navicular. AJR Am J Roentgenol 126:601, 1976.)

6S-184 The Upper Extremity  |  THE HAND

FIGURE 6S-51  Accessory ossification center for the tubercle of the navicular in a 10-year-old girl (m). Note also the accessory ossification center at the distal end of the first metacarpal (m 6 ).

FIGURE 6S-52  Accessory ossification center for the tubercle of the navicular, which failed to unite.



The Upper Extremity  |  THE HAND 6S-185

THE TRIQUETRUM BONE

FIGURE 6S-53  An example of congenital fusion of the lunate and triquetrum, a relatively common site of fusion. In childhood, the fissure between the incompletely fused bones should not be mistaken for a fracture. (Refs: Carlson DH: Coalition of the carpal bones. Skeletal Radiol 7:125, 1981; Resnik CS, et al: Incomplete carpal coalition. AJR Am J Roentgenol 147:301, 1986.)

THE PISIFORM BONE

FIGURE 6S-54  Congenital fusion of the triquetrum and pisiform bones.

6S-186 The Upper Extremity  |  THE HAND

The Metacarpals

FIGURE 6S-56  Ossicle between the bases of the second and third metacarpals.

FIGURE 6S-55  Spicules in the distal metaphyses of the metacarpals in a 3-month-old infant.

FIGURE 6S-57  Ring lesions in the heads of the metacarpals. These are probably fibrous in nature and are apparently of no clinical significance.

FIGURE 6S-58  Duplication anomaly of the second metacarpal (m 6) with an intervening articulation (m).



The Upper Extremity  |  THE HAND 6S-187

A

B

FIGURE 6S-59  Variations of the “great knob of Keats.” A, The knob in a 13-year-old child. B, The knob in a 14-year-old child.

The Sesamoid Bones

FIGURE 6S-60  Solitary sesamoids at the heads of the second metacarpals.

6S-188 The Upper Extremity  |  THE HAND

The Fingers

FIGURE 6S-61  Simulated fractures of the bases of the phalanges of the fourth and fifth fingers.

FIGURE 6S-62  Bilateral, small, spurlike projections from the bases of the proximal phalanges in a healthy 20-year-old woman.



The Upper Extremity  |  THE HAND 6S-189

FIGURE 6S-63  Abortive attempt to form triphalangeal thumbs. There were no associated anomalies in this patient.

FIGURE 6S-64  Bone island in the head of the proximal phalanx of the index finger.

FIGURE 6S-65  Speckled densities in the medullary cavities of the phalanges of both hands in a 58-year-old woman, probably representing prominent trabeculae in osteoporotic bone.

FIGURE 6S-66  Soft tissue laceration simulating fracture of the ungual tuft.

6S-190 The Upper Extremity  |  THE HAND

FIGURE 6S-67  Sclerosis of all digits in a healthy 45-year-old woman.

FIGURE 6S-68  Soft-tissue calcification of the distal phalanges of the fingers, a finding of no clinical significance that may result from mechanical injury. (From Fischer E: Weichteilverkalkungen am rand der uberositas phalangis distalis der finger. Rofo 139:150, 1983.)

CHAPTER

7

The Lower Extremity PAGES 486 486 494 506 507 518

to to to to to to

556 493 505 506 518 556

FIGURES THE THIGH The Femoral Head and Hip Joint The Femoral Neck The Trochanters The Shaft of the Femur The Distal End of the Femur

7-1 to 7-177 7-1 to 7-26 7-27 to 7-55 7-56 to 7-58 7-59 to 7-85 7-86 to 7-177

556 to 579

THE PATELLA

7-178 to 7-223

580 580 607 617

to to to to

637 606 616 637

THE LEG The Proximal Ends of the Tibia and Fibula The Shafts of the Tibia and Fibula The Distal Ends of the Tibia and Fibula

7-224 7-224 7-284 7-306

to to to to

7-365 7-283 7-305 7-365

637 637 637 653 666 683 694 705 709 740 745

to to to to to to to to to to to

759 708 652 666 682 693 704 708 739 745 759

THE FOOT The Tarsals The Accessory Ossicles The Talus The Calcaneus The Tarsal Navicular The Cuneiforms The Cuboid The Metatarsals The Sesamoid Bones The Toes

7-366 7-366 7-366 7-408 7-440 7-478 7-505 7-528 7-537 7-613 7-630

to to to to to to to to to to to

7-674 7-536 7-407 7-439 7-477 7-504 7-527 7-536 7-612 7-629 7-671

485

486

The Lower Extremity  |  THE THIGH

THE THIGH The Femoral Head and Hip Joint

A

B

FIGURE 7-1  This 2-year-old infant has Perthes disease on his left side. However, the defect in the right femoral head is a developmental variant, not incipient osteochondritis. A, Hips in neutral position. B, Hips in abduction. (Ref: Katz JF: “Abortive” Legg-Calve ´-Perthes disease or developmental variation in epiphysiogenesis of upper femur. J M Sinai Hosp N Y 32:651, 1965.)

FIGURE 7-2  Normal irregular mineralization of the ossification center of the left femoral head. This appearance in a single center in a young infant does not necessarily indicate disease. (Ref: Silverman FN, Kuhn J: Caffey’s Pediatric X-Ray Diagnosis, 9th ed. St. Louis, Mosby, 1993.)

A

FIGURE 7-3  Normal stippled appearance of one ossification center in a 10-month-old infant. Such centers evolve to normal contour with further growth. (Ref: Lemperg R, et al: Asymmetry of the epiphyseal nucleus in the femoral head in stable and unstable hip joints. Pediatr Radiol 1:191, 1973.)

B

FIGURE 7-4  A, B, Bilateral stippled appearance of the capital femoral epiphyses with progression to normal appearance. A, At 18 months of age. B, At 30 months of age.

The Lower Extremity  |  THE THIGH

487

PART 1  |  CHAPTER 7



A

B

FIGURE 7-5  Two examples of normal developmental irregularity of the femoral heads in children without hip symptoms. A, A 3-year-old boy. B, A 41⁄2-year-old boy.

FIGURE 7-6  Double ossification centers for the capital femoral epiphysis. This finding is a normal variant, not an indication of disease.

FIGURE 7-7  Cleft of the proximal femoral epiphysis in a 3-year-old girl.

FIGURE 7-8  Normal asymmetry in size of the ossification centers of the femoral heads, as shown here, is not necessarily indicative of congenital dislocation of the femoral head.

488

The Lower Extremity  |  THE THIGH

FIGURE 7-9  The femoral notch in two 9-year-old children. This defect is probably cartilaginous, because arthrography shows that it does not communicate with the joint. It may be seen as early as 4 years of age and disappears gradually over the course of months or years. (Ref: Ozonoff MB, Ziter FM Jr: The femoral head notch. Skeletal Radiol 16:19, 1987.)

FIGURE 7-10  Double femoral head notches seen on the left in a 9-year-old child.

FIGURE 7-11  Two examples of the normal irregularity of the acetabular roofs in young children. This appearance is normal between ages 7 and 12 years.

The Lower Extremity  |  THE THIGH

489

PART 1  |  CHAPTER 7



FIGURE 7-12  Normal intrapelvic protrusion of the acetabula. This is a normal phase of development between 4 and 12 years of age.

FIGURE 7-13  The fossa at the entry point of the acetabular nutrient vessels may simulate a lucent lesion of the femoral head.

FIGURE 7-14  Unusually large bilateral fovea capitis, which may be mistaken for osteochondritis dissecans.

FIGURE 7-15  Normal asymmetry of the fovea capitis.

490

The Lower Extremity  |  THE THIGH

A

B FIGURE 7-16  Simulated destructive lesions of the femoral heads produced by superimposition of the acetabular bone on the femoral head. A, Hips in neutral position. B, Hips in abduction.

FIGURE 7-18  Ossification centers for the acetabulum, which may simulate fractures of the femoral head, in a 14-year-old boy.

FIGURE 7-17  The lucent interval between the anterior (m) and the posterior lips of the acetabulum (m 6) may simulate a lucent lesion of the femoral head (m 66).

The Lower Extremity  |  THE THIGH

491

PART 1  |  CHAPTER 7



FIGURE 7-19  The “vacuum” phenomenon in normal hips of a 6-month-old child (lower arrows). The upper arrow indicates an accessory ossification center for the transverse process of L5.

FIGURE 7-20  A, B, “Vacuum” phenomenon in the hips of an adult. Note how the radiolucency in A resembles a fracture line.

A

A

B

B

FIGURE 7-21  Two examples of the unreliability of Shenton’s line after the newborn period. A, A 5-month-old infant. B, A 1-year-old child. Note particularly the asymmetry of the lines in A.

492

The Lower Extremity  |  THE THIGH

FIGURE 7-22  Apparent bulging of the hip “capsule,” suggesting synovitis or hemarthrosis, may be produced by filming of the hip in abduction and external rotation, as in this 6-year-old boy (m). Note normal fat lines on opposite side (m 6 ). (Ref: Brown I: A study of the “capsular” shadow in disorders of the hip in children. J Bone Joint Surg Br 57:175, 1975.)

FIGURE 7-23  Plump femoral heads in a 22-month-old infant. (Courtesy Dr. Clement Fauré.)

FIGURE 7-24  Note that when a line is drawn along the femoral necks for the detection of slipped capital femoral epiphysis, there is normal variability in the amount of femoral head that is intersected. This variability is illustrated in films of two adolescent boys.

The Lower Extremity  |  THE THIGH

493

PART 1  |  CHAPTER 7



A

B

FIGURE 7-25  A, B, Bilateral developmental spurs at the edge of the closed physis in a 30-year-old man, possible remnants of epiphyseal spurs.

A FIGURE 7-26  A, Hypertrophic changes at the femoral head may produce an appearance simulating a fracture of the femoral neck. B, C, Simulated fractures of the femoral neck produced by hypertrophic lipping of the femoral head.

B

C

The Lower Extremity  |  THE THIGH

494

The Femoral Neck

A

B

FIGURE 7-27  Normal irregularities of the metaphysial margin of the growth plate in early childhood. A, A 4-year-old girl. B, A 5-year-old boy.

FIGURE 7-28  Normal double-contour effect of cortex of the superior aspect of the femoral neck in a 4-year-old boy. This is a common appearance in children of this age.

FIGURE 7-29  The upper femoral notch (m) in a 13-year-old boy. This is probably the same lesion seen in the humeral neck and other metaphyseal sites. The lesion disappears with growth and is of no significance. Note the poor definition of the upper margin of the femoral neck (m 6), also a normal appearance at this age. (Ref: Ozonoff MB, Ziter FM Jr: The upper femoral notch. Skeletal Radiol 14:198, 1985.)

The Lower Extremity  |  THE THIGH

495

PART 1  |  CHAPTER 7



FIGURE 7-30  An example of the entities described in Figure 7-29 seen here bilaterally in a 12-year-old boy.

FIGURE 7-31  Two additional examples of the upper femoral notch.

A

B FIGURE 7-32  A, B, Probable residua of the upper femoral notches in a 35-year-old woman.

496

The Lower Extremity  |  THE THIGH

FIGURE 7-33  Normal irregularities and lucencies in the femoral necks of an 11-year-old boy.

FIGURE 7-34  Normal lucencies in the femoral necks of a 16-year-old boy.

FIGURE 7-35  Normal lucencies in the necks of the femora (Ward’s triangle), formed by the angle of the trabeculae in the neck of the femur.

The Lower Extremity  |  THE THIGH

497

PART 1  |  CHAPTER 7



FIGURE 7-36  Bilateral localized trabecular radiolucencies in the femoral necks of a healthy 53-year-old woman.

A

B FIGURE 7-37  A, Pseudolesion of right femoral neck in osteoporosis. B, CT shows no lesions.

FIGURE 7-38  Top left, Normal triangular radiolucencies in the femoral necks produced by the heavy trabeculations in the center of the femoral neck and the overlap of the femoral head medially. Top right, This appearance may be asymmetric in its presentation. Bottom left and right, Similar radiolucencies may be seen in the frog-leg projection.

498

The Lower Extremity  |  THE THIGH

FIGURE 7-39  Trabecular reinforcement of the femoral necks secondary to osteoporosis. These alterations should not be confused with the trabecular changes of Paget’s disease.

FIGURE 7-40  Better-defined trabeculation as seen in Figure 7-39 in elderly woman.

The Lower Extremity  |  THE THIGH

499

PART 1  |  CHAPTER 7



FIGURE 7-41  Relative radiolucencies in the femoral necks of an 85-year-old man, produced by the large trabeculations of the femoral neck inferior and medial to the edge of the greater trochanter.

FIGURE 7-42  Radiolucencies produced by overlap of the greater trochanter and the heavy trabeculation of the femoral neck in a 51-year-old man.

FIGURE 7-43  Slight rotation of the right femur produces an apparent lesion in the intertrochanteric region of the right femur.

500

The Lower Extremity  |  THE THIGH

A

B

FIGURE 7-44  Typical juvenile benign cortical defects are occasionally seen in the femoral neck and are of no clinical significance. A, At 7 years. B, Three years later, the lesion is slightly larger.

FIGURE 7-45  Examples of ringlike radiolucencies of the femoral necks with sclerotic borders. These common lesions are apparently of no clinical significance. There is evidence to suggest that they represent a subcortical pit formed by herniation of synovium through the cortical bone. (Ref: Pitt MJ, et al: Herniation pit of the femoral neck. AJR Am J Roentgenol 38:1115, 1982.) Rarely, these herniation pits may grow rapidly and suggest an aggressive lesion. In some cases the pits may enlarge, and the overlying cortex may fracture and become symptomatic. (Ref: Daenen B, et al: Symptomatic herniation pits of the femoral neck: Anatomic and clinical studies. AJR Am J Roentgenol 168:149, 1997.)

The Lower Extremity  |  THE THIGH

501

PART 1  |  CHAPTER 7



FIGURE 7-46  Large herniation pit with demonstration on CT scan.

A

B

C FIGURE 7-47  Large herniation pit. A, Plain film. B, T1-weighted MR image. C, Fat-saturated T2-weighted MR image.

502

The Lower Extremity  |  THE THIGH

A

B

C

D1

D2

FIGURE 7-48  Examples of bony thickenings of the inferior aspects of the femoral necks, probably caused by ossification of the inferior retinaculum of the synovial capsule. A, B, A 34-year-old woman; C, D1, and D2, A 25-year-old woman. (A and B courtesy Dr. Clement Fauré.) (Ref: Fauré C, et al: L’éperon pectineo-foveal du col fémoral. J Radiol 64:505, 1983.)

The Lower Extremity  |  THE THIGH

503

PART 1  |  CHAPTER 7



A

B

C

D

FIGURE 7-49  A through D, Four examples of the “white line” of the femoral neck, which probably represents the posterior insertion of the joint capsule. This may be confused with a fracture line.

FIGURE 7-50  Localized reinforcement of major trabeculae in a 75-year-old osteoporotic woman that might be mistaken for an insufficiency fracture.

504

The Lower Extremity  |  THE THIGH

A

B

FIGURE 7-51  A, Normal area of radiolucency of the femoral neck; radiolucency is more marked in individuals with osteoporosis. B, This area radiolucency simulates a pathologic fracture in patients with traumatic fracture of the femoral neck caused by rotation of the head. After reduction this appearance is no longer seen. (Ref: Pope TL Jr, et al: Pseudopathologic fracture of the femoral neck. Skeletal Radiol 7:129, 1981.)

FIGURE 7-52  Additional example of a simulated destructive lesion after fracture of an osteoporotic femur.

FIGURE 7-53  Left, Simulated fracture of the femoral neck in a 68-year-old woman, produced by hypertrophic lipping, best seen in the lateral projection (right).

The Lower Extremity  |  THE THIGH

505

PART 1  |  CHAPTER 7



FIGURE 7-54  Two examples of skin folds simulating fractures of the femur.

FIGURE 7-55  Prominent vertical striation of the bone of the femoral neck in a normal 12-year-old girl.

506

The Lower Extremity  |  THE THIGH

The Trochanters

FIGURE 7-56  Normal irregularity of the ossification centers of the greater and lesser trochanters in a 3-year-old girl.

A

FIGURE 7-57  Normal irregularity of the trochanteric apophyseal line in a 7-year-old boy

B FIGURE 7-58  Accessory ossification center of the greater trochanter in a 16-year-old girl. A, Plain film. B, CT scan.

The Lower Extremity  |  THE THIGH

507

The Shaft of the Femur

FIGURE 7-60  Physiologic “periostitis” of the newborn. This finding is not seen before the age of 1 month, is symmetric in distribution although not necessarily concentric, and may be seen in only one view. (Ref: Shopfner CE: Periosteal bone growth in normal infants: A preliminary report. Am J Roentgenol Radium Ther Nucl Med 97:154, 1966.)

FIGURE 7-59  Normal osteosclerosis of the premature. This sclerosis is caused by the proportionally thicker cortical bone and incomplete development of the medullary cavities. This appearance reverts to normal in the first weeks of life.

FIGURE 7-61  Additional examples of physiologic “periostitis” of the newborn, seen in two 4-month-old infants. Incorporation, evident here, is essentially completed by 6 months of age.

PART 1  |  CHAPTER 7



508

The Lower Extremity  |  THE THIGH

FIGURE 7-62  Physiologic anterior bowing of the femurs in a heavy 19-month-old girl. This is a self-limited phenomenon that disappears as the child matures.

FIGURE 7-63  Combined anterior and lateral physiologic bowing of the tibias in a 12-month-old girl.

The Lower Extremity  |  THE THIGH

509

PART 1  |  CHAPTER 7



FIGURE 7-64  Bilateral localized changes in the femurs of a 78-year-old man that are thought to represent the origin of the vastus lateralis muscles. (Courtesy Dr. Ann Gabrielle Bergman.)

510

The Lower Extremity  |  THE THIGH

B

A

C FIGURE 7-65  Origin of the vastus lateral muscle on plain film (A) and on T1-weighted sagittal (B) and axial (C) MR images.

FIGURE 7-66  Speckled trabeculation of the intertrochanteric area, which should not be mistaken for cartilaginous tumor matrix or bone infarction. These are reinforced trabeculae seen in osteoporotic bone. (Ref: Kerr R, et al: Computerized tomography of proximal femoral trabecular patterns. J Orthop Res 4:45, 1986.)

The Lower Extremity  |  THE THIGH

511

PART 1  |  CHAPTER 7



A

B

FIGURE 7-67  Development of the speckled pattern of the femur in a young woman immobilized after a stroke. A, Baseline. B, Four years later, the bone has become osteopenic from disuse, and speckles have appeared.

FIGURE 7-68  Very lucent femoral metaphyses in osteoporosis.

FIGURE 7-69  Multiple transverse lines in the femoral shaft in a healthy 35-year-old man. These were present bilaterally. The same phenomenon can be seen in the humerus.

512

The Lower Extremity  |  THE THIGH

FIGURE 7-70  The femoral linea aspera–pilaster complex for the insertion of the adductor and extensor muscles. (Ref: Pitt MJ: Radiology of the femoral linea aspera-pilaster complex: The track sign. Radiology 142:66, 1982.)

A

B

C

FIGURE 7-71  Left, The pilaster complex misdiagnosed as a fracture of the femur (m). Right, CT scan shows the cortical ridge (m) but no fracture.

D

FIGURE 7-72  A through D, The same entity as shown in Figure 7-71, seen bilaterally. Note the simulated periostitis in the lateral projections (B and D).

The Lower Extremity  |  THE THIGH

513

PART 1  |  CHAPTER 7



A

B

C

D

FIGURE 7-73  A through D, Bilateral linear intramedullary densities of the femurs in a 22-year-old woman. (Courtesy Dr. J.C. Hoeffel.)

A

B

C

D

FIGURE 7-74  A through D, Bilateral linear intramedullary densities of the femurs in a 67-year-old woman. Seen more commonly in elderly women without known disease, such densities are apparently of no clinical significance.

514

The Lower Extremity  |  THE THIGH

FIGURE 7-75  Unusual endocortical scalloping in a 70-year-old woman with no known disease, presumably representing a reflection of osteoporosis.

FIGURE 7-76  Normal nutrient vascular channels of the femora.

The Lower Extremity  |  THE THIGH

515

PART 1  |  CHAPTER 7



FIGURE 7-77  Nutrient foramen in a 7-year-old boy that, when added to the normal cortical thickening of the posterior aspect of the femur, was mistaken for an osteoid osteoma. Left, Frontal projection. Center, Lateral projection. Right, CT scan.

FIGURE 7-78  The nutrient channel of the femur.

FIGURE 7-79  Three examples of lucent fissures in the posterior cortex of the femur that might be mistaken for fracture lines.

516

The Lower Extremity  |  THE THIGH

FIGURE 7-80  Typical juvenile benign cortical defects. These lesions are very common in the distal femur and are of no clinical significance. (Ref: Ritschl P, et al: Fibrous metaphyseal defects: Determination of their origin and natural history using a radiomorphological study. Skeletal Radiol 17:8, 1988.)

A

B

C

FIGURE 7-81  Additional examples of juvenile benign cortical defects. A, Multiloculate. B, Multiple lesions with thick sclerotic margins. C, Healing.

The Lower Extremity  |  THE THIGH

517

PART 1  |  CHAPTER 7



FIGURE 7-82  Healing juvenile benign cortical defect in a 17-year-old boy (m). Note the mixed lucency and sclerosis. Note also the longitudinal striations in the metaphysis, a common finding in young people (m 66).

FIGURE 7-83  Huge healed juvenile benign cortical defect in an 18-year-old woman.

518

The Lower Extremity  |  THE THIGH

FIGURE 7-84  Very dense healed juvenile benign cortical defect in a 24-year-old woman.

FIGURE 7-85  Prominent longitudinal striations of the bone in a normal 13-year-old girl.

The Distal End of the Femur

FIGURE 7-86  “Tug” lesion of the medial aspect of the distal femur in an adolescent, representing bone formation in the insertion of the adductor magnus muscle. (Ref: Barnes GR Jr, Gwinn JL: Distal irregularities of the femur simulating malignancy. Am J Roentgenol, Radium Ther Nucl Med 122:180, 1974.)

FIGURE 7-87  Additional example of the “tug” lesion of the femur in an adult (m). Note also calcification in the medial collateral ligament (m 6) and an ossicle below of the same etiology (m 66).

The Lower Extremity  |  THE THIGH

519

PART 1  |  CHAPTER 7



FIGURE 7-88  Very large “tug” lesion of the medial femoral metaphysis resembling an osteochondroma.

FIGURE 7-89  Bilateral cortical thickenings related to insertion of the vastus lateralis muscle, a common radiologic finding, in a young man.

520

The Lower Extremity  |  THE THIGH

A

B FIGURE 7-90  Prominent insertion of the medial head of the gastrocnemius. A, Plain film. B, T2-weighted MR image.

FIGURE 7-91  Normal triangular area of radiolucency seen in the metaphysis of the distal femur in an osteoporotic individual (m). The density in the midportion is related to the linea aspera (m 66).

FIGURE 7-92  Triangular radiolucency in an 11-year-old girl.

The Lower Extremity  |  THE THIGH

521

PART 1  |  CHAPTER 7



FIGURE 7-93  Normal lucencies in the distal femur mistaken for metastases in a patient with breast carcinoma. The lateral projections were normal.

FIGURE 7-94  Nutrient foramen of the distal femur.

FIGURE 7-95  Examples of transverse (“growth”) lines of the distal femoral metaphyses. Although frequently associated with disease states, these lines are often seen in patients without contributory history.

522

The Lower Extremity  |  THE THIGH

FIGURE 7-96  Detailed view of transverse lines of the distal femur in a younger child.

FIGURE 7-97  Two examples of normal metaphyseal radiolucencies, an accompanying feature of osteosclerosis of the newborn (see Fig. 7-59). The new bone formed at the metaphysis is often more radiolucent, producing an appearance that might be mistaken for evidence of systemic disease. This finding is often the product of intrauterine stress.

FIGURE 7-98  Dense zones of provisional calcification are often mistaken for the lines of heavy metal poisoning. These zones vary considerably in thickness in healthy children and in the same child at different ages. They tend to be proportionately thicker during the second to fifth years. (Ref: Silverman FN, Kuhn J: Caffey’s Pediatric X-Ray Diagnosis, 9th ed. St. Louis, Mosby, 1993.)

A

B

FIGURE 7-99  Additional examples of normal zones of provisional calcification. A, A 14-month-old child. B, A 2-year-old child.

The Lower Extremity  |  THE THIGH

523

PART 1  |  CHAPTER 7



FIGURE 7-100  Two examples of normal irregularity in ossification of the posterior aspect of the distal femur in 2-year-old children.

A

B

FIGURE 7-101  A, The posterior irregularity of the posterior aspect of the distal femur in a 2-year-old child. B, Note the radiolucency in the medial aspect of the femoral metaphysis, which is probably the product of the posterior cortical irregularity.

FIGURE 7-102  Four examples of the metaphyseal radiolucencies illustrated in the previous figure, seen here in 5- and 6-year-old children.

The Lower Extremity  |  THE THIGH

524

FIGURE 7-103  Irregularity of the anterior aspect of the femoral metaphysis in a 3-year-old boy.

A B

C

FIGURE 7-104  Three examples of irregularity of the cortex of the anterior aspect of the femur, immediately above the epiphyseal line. This entity is seen in adolescence and is a transient event. A, An 11-year-old boy. B, A 13-year-old boy. C, A 15-year-old boy.  (Ref: Keats TE: The distal anterior femoral metaphyseal defect: An anatomic variant that may simulate disease. Am J Roentgenol Radium Ther Nucl Med 121:101, 1974.)

The Lower Extremity  |  THE THIGH

525

PART 1  |  CHAPTER 7



A

B

FIGURE 7-105  A, B, Irregular defect in the cortex of the medial posterior aspect of the distal femur is a common finding between ages 12 and 16 years. This is a fibrous lesion, which often demonstrates fine perpendicular spiculation of bone (B) and may be mistaken for a malignant bone tumor. It appears to be developmental in origin and disappears with advancing age. The lesion seems to be similar in nature to other metaphyseal irregularities seen elsewhere in the body at the same age. It is important to note that the metaphyseal irregularities in the medial posterior aspects of the distal end of the femur are “cold” on nuclear scanning, suggesting that they are not avulsive in nature. (Refs: Brower AC, et al: The histologic nature of the cortical irregularity of the medial posterior distal femoral metaphysis in children. Radiology 99:389, 1971; Burrows PE: The distal femoral defect: Technetium 99m pyrophosphate bone scan results. J Can Assoc Radiol 33:91, 1982.)

FIGURE 7-106  Good detail of the architecture of the medial femoral cortical irregularity in a 15-year-old boy.

FIGURE 7-107  Medial femoral cortical irregularity in a 13-year-old boy with a large spur at the inferior margin of the lesion (m).

526

The Lower Extremity  |  THE THIGH

FIGURE 7-108  Distal femoral cortical irregularities on both sides in a 10-year-old boy.

A

C

B

FIGURE 7-109  Residua of the irregularity of the cortex in the area of the medial femoral defects described in Figures 7-107 and 7-108. A, A 17-year-old boy. B, A 23-year-old man. C, A 35-year-old man.

A

B

FIGURE 7-110  A, Typical benign cortical defect of the femur in a 12-year-old boy. B, Follow-up film made 3 years later shows the typical medial cortical irregularity. This evolution lends weight to the concept of the similar nature of these two entities.

The Lower Extremity  |  THE THIGH

527

PART 1  |  CHAPTER 7



FIGURE 7-111  The medial distal femoral cortical irregularity in a 13-year-old boy. Note the spiculations of bone (m) and the absence of cortex. The nuclear scan appearance was normal.

FIGURE 7-112  Coexistence of the medial posterior cortical defect (m) and a benign cortical defect (m 66).

FIGURE 7-113  Irregularity of the posterior aspect of the distal femur is a common finding in adolescents that is often mistaken for the new bone formation of a neoplasm. This lesion is apparently related to the medial cortical irregularity illustrated in Figure 7-105 and is of no clinical significance. It is “cold” on nuclear scanning, suggesting that it is not an avulsive injury and is more likely to be a reflection of growth. (Refs: Bufkin WJ: The avulsive cortical irregularity. Am J Roentgenol Radium Ther Nucl Med 112:487, 1971; Burrows PE, et al: The distal femoral defect: Technetium-99m pyrophosphate bone scan results. J Can Assoc Radiol 33:91, 1982.)

FIGURE 7-114  The posterior femoral cortical irregularities on CT scan.

528

The Lower Extremity  |  THE THIGH

A

B

D

C

E FIGURE 7-115  A through E, The posterior cortical irregularity of the femur in a 7-year-old child. A, B, Radiographs. C, T1-weighted sagittal MR image. D, T1-weighted axial MR image. E, Short tau inversion recovery (STIR) axial MR image. (Ref: Yamazaki T, et al: MRI findings of avulsive cortical irregularity of the distal femur. Skeletal Radiol 24:43, 1995.)

The Lower Extremity  |  THE THIGH

529

PART 1  |  CHAPTER 7



A

C

B

D

FIGURE 7-116  The posterior cortical irregularity of the femur in a 12-year-old boy. A, B, Plain films. C, T1-weighted MR image shows area of low signal intensity in that portion of the medullary cavity. D, T2-weighted MR image shows increased signal intensity at that site. (Ref: Yamezaki T, et al: MR findings of avulsive cortical irregularity of the distal femur. Skeletal Radiol 24:43, 1995.)

530

The Lower Extremity  |  THE THIGH

A

B

C

D

FIGURE 7-117  A through D, Huge symmetric bilateral posterior cortical irregularities in a 10-year-old girl.

FIGURE 7-118  Large irregular posterior femoral defect in a 12-year-old girl that was proven by biopsy to be fibrous in nature.

The Lower Extremity  |  THE THIGH

531

PART 1  |  CHAPTER 7



FIGURE 7-119  Residua of the posterior femoral defect in a 30-year-old man.

B

A FIGURE 7-120  A, B, A more exaggerated residuum of the posterior femoral defect in a 33-year-old man.

532

The Lower Extremity  |  THE THIGH

FIGURE 7-121  Developmental excavation on the posterior aspect of the medial femoral condyle.

FIGURE 7-122  Four examples of cortical irregularities in the posterior cortex of the distal femur that have persisted into adult life, presumably the end products of the process shown in Figures 7-113 and 7-118. These defects are important only because they might be mistaken for significant lesions.

The Lower Extremity  |  THE THIGH

533

PART 1  |  CHAPTER 7



FIGURE 7-123  Simulated lesions of the anterior aspect of the distal femur produced by rotation at the time of filming.

A

B

FIGURE 7-124  Physiologic bowing and knock-knee. A, Physiologic bowing in a 11⁄2-year-old girl. B, Physiologic knock-knee in a 31⁄2-year-old girl. In normal development, there is a varoid phase to age 2 years and a valgoid phase between 2 and 12 years. These are normal physiologic events that correct spontaneously. (Refs: Holt JF, et al: Physiological bowing of the legs in young children. J Am Med Assoc 154:390, 1954; Shopfner CE, Coin CG: Genu varus and valgus in children. Radiology 92:723, 1968.)

534

The Lower Extremity  |  THE THIGH

FIGURE 7-126  Physiologic knock-knees in a 3-year-old boy. Note lack of any architectural derangement.

FIGURE 7-125  Physiologic bowing. Note the slight beaking of the medial tibial plateaus, the medial wedging of the ossification centers of the knees, and the thickening of the medial cortices of the tibias. These are all reflections of this physiologic state.

A

B

C

FIGURE 7-127  Evolution of physiologic bowing. A, An 18-month-old child. B, A 2-year-old child showing spontaneous correction. C, A 4-year-old child. This appearance is normal.

The Lower Extremity  |  THE THIGH

535

PART 1  |  CHAPTER 7



A

B

FIGURE 7-128  A, A 1-year-old girl with physiologic bowing. Note the “fragmentation” of the medial aspect of the tibial metaphysis (m). B, Same patient at age 2 years. Note resolution of the physiologic bowing.

FIGURE 7-129  Asymmetric development of the distal femoral epiphysis in a 7-year-old boy with no symptoms referable to the knee joints.

536

The Lower Extremity  |  THE THIGH

FIGURE 7-130  Cleft distal femoral epiphysis seen only in the lateral projection. Any epiphysis or apophysis may develop from multiple centers.

FIGURE 7-131  Normal irregularity of ossification of the medial femoral metaphyses in young children.

The Lower Extremity  |  THE THIGH

537

PART 1  |  CHAPTER 7



FIGURE 7-132  Normal irregularities of ossification in the knees of young infants. (Ref: Caffey J, et al: Ossification of the distal femoral epiphysis. J Bone Joint Surg Am 40:647, 1958.)

538

The Lower Extremity  |  THE THIGH

FIGURE 7-133  Additional examples of normal irregularities of the distal femoral epiphyses in 1-year-old children.

FIGURE 7-134  Normal irregular ossification of the lateral aspect of the distal femoral epiphysis in a 9-year-old child.

The Lower Extremity  |  THE THIGH

539

PART 1  |  CHAPTER 7



C A

B

FIGURE 7-135  A, Normal developmental lucency of the lateral aspects of the distal femoral epiphysis simulating a destructive lesion in a 6-year-old boy. B, Similar but less marked changes are present in the opposite limb. C, Similar changes in a 12-year-old boy.

FIGURE 7-136  Normal developmental lucencies in the epiphyses and metaphyses of the distal femur in a 10-year-old boy.

540

The Lower Extremity  |  THE THIGH

A

B

FIGURE 7-137  Developmental radiolucent stripes in the medial aspect of the distal femoral epiphysis simulating a fracture. A, A 5-year-old boy. B, A 7-year-old boy.

FIGURE 7-138  An excellent example of the normal irregularity of the distal femoral epiphyses in an 8-year-old. This appearance explains the misleading shadows seen in the frontal projections of the knees of children of this age.

A

B

C

FIGURE 7-139  A through C, Normal irregularity of the lateral femoral condyles in a 7-year-old boy. These irregularities are posteriorly located and are seen in the tunnel views of both knees (B and C) but not in the conventional AP projection (A). (Ref: Caffey J, et al: Ossification of the distal femoral epiphysis. J Bone Joint Surg Am 140:647, 1958.)

The Lower Extremity  |  THE THIGH

541

PART 1  |  CHAPTER 7



FIGURE 7-140  Medial and lateral femoral condylar irregularities seen in the tunnel views of both knees of a 10-year-old boy. These irregularities are often mistaken for evidence of osteochondritis.

FIGURE 7-141  Simulated osteochondritis dissecans in a 6-year-old boy.

542

The Lower Extremity  |  THE THIGH

FIGURE 7-142  Simulated osteochondritis dissecans in an 11-year-old boy. Note that the irregularities are not seen in the frontal projection (left), are well demonstrated in the tunnel projection (middle), and are seen posteriorly in the lateral projection (right).

B

C

A FIGURE 7-143  Normal irregularity in ossification of the medial femoral condyle in a 12-year-old boy that was mistaken for osteochondritis dissecans. A, Plain film. B, C, Coronal and sagittal gradient echo, T2*-weighted MR images show typical ossification variant.

The Lower Extremity  |  THE THIGH

543

PART 1  |  CHAPTER 7



A

C

B

FIGURE 7-144  Normal irregularity in ossification of the medial femoral condyle in a 10-year-old girl simulating osteochondritis dissecans on radiograph (A) and on T1-weighted (B) and gradient echo, T2-weighted (C) MR images.

A

B

C

FIGURE 7-145  Normal irregularities in ossification of the lateral femoral condyle in an 8-year-old boy. A, Frontal projection. B, Oblique projection. C, Lateral projection.

544

The Lower Extremity  |  THE THIGH

A

B

C

D

FIGURE 7-146  Ossification variant of the medial femoral condyle of the left knee in a 12-year-old boy. A, AP film. B, Oblique view. C, Oblique projection. D, CT scan shows no evidence of osteochondritis dissecans.

FIGURE 7-147  Spurlike configuration of the medial femoral epiphysis in a 12-year-old girl, which should not be mistaken for an epiphyseal osteochondroma. (Ref: Kohler A, Zimmer EA: Borderlands of the Normal and Early Pathologic Findings in Skeletal Roentgenology, 3rd ed. New York, Grune & Stratton, 1968.)

The Lower Extremity  |  THE THIGH

545

PART 1  |  CHAPTER 7



A

B

FIGURE 7-148  The terminal sulcus of the lateral condyle seen in the lateral projection (A) may reflect itself in the frontal plane (B) in a manner that suggests an abnormality.

FIGURE 7-149  Two additional examples of normal contour irregularities of the condyles seen in lateral projection. This contour alteration may be seen in the patellar view as well (see Fig. 7-150).

FIGURE 7-150  Normal contour alteration of the medial condyle seen in tangential projection.

FIGURE 7-151  The lateral femoral condyle may normally appear flattened. This appearance should not be mistaken for evidence of an impaction fracture.

546

The Lower Extremity  |  THE THIGH

A

B

FIGURE 7-152  A, Flattening of the lateral femoral condyle may be associated with discoid lateral meniscus, as documented by a gradient echo, T2*-weighted coronal MR image (B).

FIGURE 7-153  Osseous excrescences along the surfaces of the distal femur seen in tunnel view are not to be confused with hypertrophic lipping.

The Lower Extremity  |  THE THIGH

547

PART 1  |  CHAPTER 7



FIGURE 7-154  The grooves of the articular surface of the medial condyle of the femur represent a normal variant that should not be confused with osteochondritis or a fracture. (Ref: Harrison RB, et al: The grooves of the distal articular surface of the femur: a normal variant. AJR Am J Roentgenol 126:751, 1976.)

FIGURE 7-155  The groove for the popliteus tendon should not be mistaken for a pathologic process.

548

The Lower Extremity  |  THE THIGH

FIGURE 7-156  The grooves of the popliteus tendon seen in the tunnel view.

FIGURE 7-157  An ossicle in the popliteus groove. (Cyamella sesamoid in the popliteus tendon.)

The Lower Extremity  |  THE THIGH

549

PART 1  |  CHAPTER 7



FIGURE 7-158  A large cyamella with overgrowth of the superior margin of the popliteus groove.

A

B FIGURE 7-159  Bipartite cyamella.

550

The Lower Extremity  |  THE THIGH

A

B

C FIGURE 7-160  Variations in development of the fabella. A, Double fabella. B, Bifid fabella. C, Irregular fabella.

FIGURE 7-161  Tripartite fabella. It should be noted that the fabella and cyamella may not be present bilaterally. (Ref: Houghton-Allen BW: In the case of the fabella a comparison view of the other knee is unlikely to be helpful. Aust Radiol 45:318, 2001.)

The Lower Extremity  |  THE THIGH

551

PART 1  |  CHAPTER 7



A

B

C

D

FIGURE 7-162  Meniscal ossicle of the medial meniscus. A, AP projection. B, Lateral projection. C, T1-weighted sagittal MR image. D, Coronal short tau inversion recovery (STIR) MR image. (Ref: Schwarkowski P, et al: Medial ossicle: Radiographic and MR imaging finding. Radiology 196:47, 1995.)

FIGURE 7-163  Normal areas of sclerosis of the intercondylar fossae in a 25-year-old man.

The Lower Extremity  |  THE THIGH

552

A

B

FIGURE 7-164  The transverse intermeniscal ligament. A, Radiograph. B, T1-weighted MR image. (Ref: Sintzoff SA Jr, et al: Transverse geniculate ligament of the knee: Appearance and frequency on plain radiographs. Br J Radiol 65:766, 1992.)

FIGURE 7-165  Calcification in the posterior cruciate ligament in a patient being examined for an acute injury. FIGURE 7-166  Normal radiolucent anterior segment of the distal femoral epiphysis in a 12-year-old boy resulting from the fact that less bone is traversed anteriorly than posteriorly.

The Lower Extremity  |  THE THIGH

553

PART 1  |  CHAPTER 7



FIGURE 7-168  Triangular area of radiolucency that may be confused with the defect of osteochondritis dissecans. (Ref: Weisman JC: The medial femoral triangle of radiolucency simulating osteochondrosis dissecans. Am J Roentgenol 58:166, 1947.)  

FIGURE 7-167  Normal radiolucency simulating a cystic lesion.

FIGURE 7-169  Stippled appearance of distal femur caused by the closing epiphyseal plate in a 13-year-old boy. This appearance should not be confused with chondroid matrix of a neoplasm. FIGURE 7-170  Two examples of the foramina for the nutrient vessels of the distal end of the femur.

554

The Lower Extremity  |  THE THIGH

FIGURE 7-172  Fat pad between joint capsule and quadriceps tendon that may be mistaken for a lipohemarthrosis. (Ref: Butt WP, et al: Radiology of the suprapatellar region. Clin Radiol 34:511, 1983.)

FIGURE 7–171  Normal radiolucency of the femoral notch originally diagnosed as a metastatic deposit.

A

B FIGURE 7-173  A, B, Bilateral ossification in Hoffa’s fat pad.

The Lower Extremity  |  THE THIGH

555

PART 1  |  CHAPTER 7



FIGURE 7-174  The “vacuum” phenomenon in the knee joint.

FIGURE 7-175  Simulated narrowing of the medial compartments of the knees in a 14-year-old girl. This misleading appearance is the result of the double contour of the medial tibial plateau. Measurements should be made from the articular surface of the distal femoral condyle to the most distal of the tibial articular margins (m). Measured in this fashion, the widths of the two compartments are equal. (Ref: Fife RS, et al: Relationship between arthroscopic evidence of cartilage damage and radiographic evidence of joint space narrowing in early osteoarthritis of the knee. Arthritis Rheum 34:377, 1991.)

A

B

C

FIGURE 7-176  A, B, Simulated medial compartment narrowing on standing film for the same reason as that shown in Figure 7-175. This problem can also be resolved with a tunnel projection (C), which demonstrates equality of measurement of the two compartments.

556

The Lower Extremity  |  THE PATELLA

FIGURE 7-177  Some normal individuals show true asymmetry in the height of the medial and lateral compartments. Left, A 48-year-old man. Standing films show asymptomatic symmetric narrowing of the medial compartments. Right, Films of the same person 10 years later show no change in compartment height. (Refs: Hall FM, Wyshak G: Thickness of articular cartilage in the normal knee. J Bone Joint Surg Am 62:408, 1980; Brandt KD, et al: Radiographic grading of the severity of knee osteoarthritis. Arthritis Rheum 34:1381, 1991.)

THE PATELLA

FIGURE 7-178  Normal irregularity of the growing patellae in a 7-year-old boy.

The Lower Extremity  |  THE PATELLA

557

PART 1  |  CHAPTER 7



FIGURE 7-179  Unusual dense stippling of the patellae in a 2-year-old girl, best seen in the frontal projection. Note that the other epiphyses are normal.

558

The Lower Extremity  |  THE PATELLA

FIGURE 7-180  Normal variation in development of the patella in an 8-year-old boy simulating a fracture.

FIGURE 7-181  Normal irregularity and clefts in the patella of a 6-year-old boy.

A

B

FIGURE 7-182  Normal developmental irregularities of the patellae, seen in the tangential projection. A, A 7-year-old child. B, A 15-year-old child.

The Lower Extremity  |  THE PATELLA

559

PART 1  |  CHAPTER 7



FIGURE 7-183  Three examples of accessory ossification centers at the superior pole of the patella.

A

C

B

D

FIGURE 7-184  A, B, Irregular patellar ossification misdiagnosed as a fracture. C, Simulated fracture lines in the normal patella of a 7-year-old boy. D, Normal irregularity of the superior aspect of the patella in a 12-year-old boy simulating osteochondritis or a fracture.

The Lower Extremity  |  THE PATELLA

560

A

B

FIGURE 7-185  Variations in development of the patella in that might be mistaken for fracture. A, A 6-year-old child. B, An 8-year-old child.

A

B

C

FIGURE 7-186  Apparent fracture of the superior aspect of the patella in a 14-year-old boy as a result of a secondary ossification center at the superior pole. (Ref: Ogden JA: Radiology of postnatal skeletal development. X: Patella and tibial tuberosity. Skeletal Radiol 11:246, 1984.)

The Lower Extremity  |  THE PATELLA

561

PART 1  |  CHAPTER 7



FIGURE 7-187  Unfused accessory ossification center at the upper pole of the patella in an 80-year-old man.

A

B

FIGURE 7-188  A, B, Normal asymmetric development of accessory ossification centers in a 9-year-old child. Note apparent fragmentation of the lower pole of the patella in B.

562

The Lower Extremity  |  THE PATELLA

FIGURE 7-189  Long secondary apophysis of the anterior and inferior aspects of the patella in an 11-year-old boy.

FIGURE 7-190  Nonunion of the anterior patellar apophysis illustrated in Figure 7-189.

The Lower Extremity  |  THE PATELLA

563

PART 1  |  CHAPTER 7



A

B

C

FIGURE 7-191  Three examples of accessory ossification centers simulating fractures. A, A 7-year-old boy. B, An 8-year-old boy. C, A 12-year-old boy.

564

The Lower Extremity  |  THE PATELLA

FIGURE 7-192  Variable patterns of ossification of the inferior pole of the patella.

The Lower Extremity  |  THE PATELLA

565

PART 1  |  CHAPTER 7



FIGURE 7-193  Examples of accessory center of ossification at the lower pole of the patella that may be mistaken for a fracture.

A

B

FIGURE 7-194  A, The closing accessory center at the inferior pole of the patella was suspected of being a fracture. B, A comparison view made of the opposite knee shows an even more misleading appearance.

566

The Lower Extremity  |  THE PATELLA

FIGURE 7-195  A, Fusing accessory centers of ossification at the inferior pole of the patella. B, Fusion is now complete. Patellae with large accessory centers of this type often tend to attain the elongated configuration illustrated in B. They may be associated with patella alta.

A

B

FIGURE 7-196  Unfused accessory ossification center at the inferior pole of the patella in a 19-year-old man, showing its closure over a 3-month period.

FIGURE 7-197  Developmental clefts in the patella of a 17-year-old boy.

The Lower Extremity  |  THE PATELLA

567

PART 1  |  CHAPTER 7



FIGURE 7-198  Patellar clefts.

FIGURE 7-199  Accessory ossicle at the medial aspect of the patella.

FIGURE 7-200  Unusual spurlike configuration of the medial aspect of the patella in a 20-year-old man.

FIGURE 7-201  Early bipartite patella in a 10-year-old girl.

568

The Lower Extremity  |  THE PATELLA

FIGURE 7-202  Bipartite patella, which may easily be mistaken for a fracture. Note the well-defined space between the major elements.

FIGURE 7-203  An additional example of a bipartite patella, which is well demonstrated in the tangential projection. The rounded contour of the patellar elements seen in this projection is useful in the differentiation from fracture.

The Lower Extremity  |  THE PATELLA

569

PART 1  |  CHAPTER 7



A

B

C

FIGURE 7-204  A, Segmented patellae with two pieces on patients right and three on the left. B, C, Segmented patella with four pieces.

The Lower Extremity  |  THE PATELLA

570

A

B

C

E

D

F

FIGURE 7-205  A, Unilateral bipartite patella. Note that the smaller elements in bipartite patellae often do not accurately correspond in size with the adjacent fossa. B, Unilateral bipartite patella (m), but with corresponding fossa on opposite side (m 6 ). C, D, Bipartite patella on the medial side. The majority of bipartite patellae are located on the lateral side. E, F, Tripartite patella.

The Lower Extremity  |  THE PATELLA

571

PART 1  |  CHAPTER 7



FIGURE 7-206  Tripartite patella. Note the rounded contours in the tangential projection.

FIGURE 7-207  Three examples of forme fruste bipartite patella.

A

B

FIGURE 7-208  A, The smaller element of a bipartite patella is usually smaller than the fossa in the major portion. B, Occasionally, however, it is larger than the fossa.

572

The Lower Extremity  |  THE PATELLA

A B FIGURE 7-209  An unusual variety of partitioned patella. A, Radiograph. B, Tomogram.

FIGURE 7-210  Horizontal bifid patella, a rare type of segmentation. (Ref: Weinberg S: Horizontal bifid patella. Skeletal Radiol 7:223, 1981.)

B

A FIGURE 7-211  A, B, Patellar “teeth” caused by spurring of the tendon interdigitations. (Ref: Greenspan A, et al: “Tooth” sign in patellar degenerative disease. J Bone Joint Surg Am 59:483, 1977.)

The Lower Extremity  |  THE PATELLA

573

PART 1  |  CHAPTER 7



C

B

A

D FIGURE 7-212  A, B show the dorsal patellar defect. These cortical lucencies are of no clinical significance and should not be confused with osteochondritis dissecans of the patella. C, Film obtained 1 year later; note the sclerosis of healing. D, In film obtained 2 years later, resolution is complete. (Ref: Haswell DM, et al: The dorsal defect of the patella. Pediatr Radiol 4:238, 1976.)

A

B

FIGURE 7-213  The dorsal patellar defect on plain film (A) and gradient echo, T2*-weighted axial MR image (B).

574

The Lower Extremity  |  THE PATELLA

FIGURE 7-214  Dorsal patellar defects in a 12-year-old girl.

FIGURE 7-215  Bilateral areas of increased sclerosis in the posterior surfaces of the patellae in a 20-year-old woman.

The Lower Extremity  |  THE PATELLA

575

PART 1  |  CHAPTER 7



FIGURE 7-216  Variation in ossification of the articular surface of the patella and the adjacent femoral physis.

FIGURE 7-217  Simulated fracture of the upper pole of the patella produced by a small flangelike projection, best seen in the lateral projection.

The Lower Extremity  |  THE PATELLA

576

B

A

C FIGURE 7-218  A through C, Example of simulated stress fracture of the patella from same cause as described in Figure 7-217. Note that no discontinuity is seen in the lateral projection (B) or in the tomogram (C).

A

B

C

FIGURE 7-219  Unusual configurations of the lower poles of the patellae. A, B, A 12-year-old. C, A 14-year-old girl.

The Lower Extremity  |  THE PATELLA

577

PART 1  |  CHAPTER 7



FIGURE 7-220  Unusual configurations of the patella resulting from enthesopathy.

FIGURE 7-221  Two examples of ossicles or sesamoid bones in the patellar tendon.

578

A

The Lower Extremity  |  THE PATELLA

B FIGURE 7-222  A, B, Bilateral striking appearance of the fossa in the articular surface of the patella.

The Lower Extremity  |  THE PATELLA

579

PART 1  |  CHAPTER 7



A

B

C D FIGURE 7-223  The normal fossa in the articular surface of the patella. A, Left knee. B, Right knee. C, T1-weighted MR image of right knee showing the fossa. (m) D, Fat-saturated T2-weighted MR image of right knee showing normal overlying cartilage.

580

The Lower Extremity  |  THE LEG

THE LEG The Proximal Ends of the Tibia and Fibula

FIGURE 7-224  The third tibial spine is seen at the insertion of the anterior cruciate ligament in the anterior intercondylar area. (Ref: Kohler A, Zimmer EA: Borderlands of the Normal and Early Pathologic Findings in Skeletal Roentgenology, 4th ed. New York, Thieme, 1993.)

A

B FIGURE 7-225  A, B, The third (m) and fourth tibial spines (see Fig. 7-224). The fourth tibial spine is seen at the insertion by the posterior cruciate ligament in the posterior intercondylar area.

The Lower Extremity  |  THE LEG

581

PART 1  |  CHAPTER 7



FIGURE 7-226  Spur on the tibial plateau in the absence of degenerative joint disease, possibly at the attachment of the anterior cruciate ligament. This entity is known as Parson’s knob. Increasing size of the knob is said to be a reflection of enthesopathy. (Ref: Brossmann J, et al: Enlargement of the third intercondylar tubercle of Parson’s as a sign of osteoarthritis of the knee. Radiology 198:845, 1996.)

The Lower Extremity  |  THE LEG

582

A

B

C FIGURE 7-227  Parson’s knob on plain film (A), gradient echo, T2*-weighted MR image (B), and T1-weighted MR image (C).

The Lower Extremity  |  THE LEG

583

PART 1  |  CHAPTER 7



A

B FIGURE 7-228  An ossicle in the intercondylar notch.

A

B

FIGURE 7-229  A, Lucency of lateral aspect of the tibial eminence that corresponds to the undulating bone at insertion of the anterior cruciate ligament. B, T1-weighted MR image.

584

The Lower Extremity  |  THE LEG

FIGURE 7-230  Bilateral accessory ossification centers at the medial edges of the proximal tibial metaphyses in a 7-year-old child.

FIGURE 7-231  Accessory ossification center at anterior aspect of the tibial epiphysis in a 9-year-old girl.

FIGURE 7-232  Normal depressions in the anterior tibia of a 4-year-old. These depressions disappear with the development of the ossification center for the tibial tubercle.

FIGURE 7-233  Unusually long anterior fossa for the developing tibial tubercle.

The Lower Extremity  |  THE LEG

585

PART 1  |  CHAPTER 7



FIGURE 7-234  Normal variations in appearance of the apophysis of the tibial tubercle. None of these is necessarily indicative of Osgood-Schlatter disease.

FIGURE 7-235  A separate, un-united ossification center for the tibial tubercle in a young adult. This finding should not be confused with a fracture.

586

The Lower Extremity  |  THE LEG

A

B

FIGURE 7-236  A, The unfused ossification centers for the tibial tubercle, seen in the tangential view (B). (Ref: Bloom R, et al: Ossicles anterior to the proximal tibia. Clin Imaging 17:137, 1993.)

FIGURE 7-237  Large tibial tubercle simulating an intraarticular loose body on tangential projection.

FIGURE 7-238  Normal extension of the epiphysis into the metaphysis similar to that of Kump’s hump in the ankle.

The Lower Extremity  |  THE LEG

587

PART 1  |  CHAPTER 7



FIGURE 7-239  Normal asymmetry of the epiphyseal widths in a 13-year-old boy not to be mistaken for a Salter-Harris type 1 fracture.

A

B

FIGURE 7-240  A, B, Bilateral factitious radiolucencies in the lateral aspects of the tibial plateaus in a 23-year-old man.

588

The Lower Extremity  |  THE LEG

FIGURE 7-241  Ringlike lesions in the proximal tibia are of no clinical significance. They are probably fibrous in nature. Similar lesions are seen in the fibula (see Fig. 7-308).

The Lower Extremity  |  THE LEG

589

PART 1  |  CHAPTER 7



B

A

D C FIGURE 7-242  An appearance similar to the lesions in Figure 7-241 may be produced by ganglion cysts. A, B, Radiographs. C, T1-weighted sagittal MR image. D, Gradient echo T2-weighted sagittal MR image.

FIGURE 7-243  A, Medial metaphyseal cortical irregularity of the tibia in an adolescent. This is a developmental phenomenon similar to that seen in the humerus, the radius, and the femur. B, On follow-up film, the irregularity was replaced by a typical benign cortical defect, suggesting the interrelationship of these lesions.

A

B

590

The Lower Extremity  |  THE LEG

FIGURE 7-244  Normal fossae at the medial tibial metaphysis should not be mistaken for erosions. In the elderly, they appear exaggerated because of spurring of the joint margin.

FIGURE 7-245  Developmental notch on the medial aspect of the tibial plateau in a 15-year-old boy.

FIGURE 7-246  Bilateral developmental tibial spurs with no associated abnormalities.

The Lower Extremity  |  THE LEG

FIGURE 7-247  A more marked example of exaggerated developmental bulge of the medial tibial metaphysis.

A

B

FIGURE 7-248  A, Simulated fracture of the proximal tibia caused by rotation at the time of filming. B, Correct positioning shows no fracture.

FIGURE 7-249  Spurlike extensions of the tibia in the tibial–fibular articulation.

591

PART 1  |  CHAPTER 7



592

The Lower Extremity  |  THE LEG

FIGURE 7-250  Prominent sulcus in the posterior lateral aspect of the tibia.

FIGURE 7-251  The open apophysis for the tibial tubercle, which should not be mistaken for a fracture.

The Lower Extremity  |  THE LEG

593

PART 1  |  CHAPTER 7



A

B

C

D

FIGURE 7-252  A through D, Shadows of the physis and tibial tubercule producing simulated fracture of the tibial metaphysis seen bilaterally in a 14-year-old boy (A and B, Right knee; C and D, Left knee.)

594

The Lower Extremity  |  THE LEG

FIGURE 7-253  Simulated fracture of the tibia produced by overlapping of the fibula posteriorly (m) and trabeculations anteriorly (m 66).

FIGURE 7-254  Radiolucency produced by the tibial tubercle en face.

FIGURE 7-255  The tibial tuberosity simulating a lesion.

The Lower Extremity  |  THE LEG

595

PART 1  |  CHAPTER 7



FIGURE 7-256  Three examples of pseudoperiostitis simulated by the tibial tuberosity.

FIGURE 7-257  Laminated appearance of the tibial tubercle, not to be confused with periosteal new bone formation.

596

The Lower Extremity  |  THE LEG

FIGURE 7-258  Note the varied prominence of the anterior tibial crest with various degrees of rotation. Note also the radiolucency that appears in the medial aspect of the tibial metaphysis with rotation.

FIGURE 7-259  Apparent fracture of the neck of the fibula produced by rotation and overlap of the open apophysis of the tibial tubercle.

FIGURE 7-260  Thickening of the anterior cortex of the tibia producing an unusual appearance in the frontal projection.

The Lower Extremity  |  THE LEG

597

PART 1  |  CHAPTER 7



A

B

FIGURE 7-261  A, B, Healed benign cortical defect simulating the changes of a runner’s stress fracture. Note remaining radiolucency in the proximal end of the lesion in A.

A

B

FIGURE 7-262  A, Simulated dislocation of the head of the fibula produced by filming in slight rotation. Note medial position of the patella. B, Opposite side showing proper positioning and normal relationships.

598

The Lower Extremity  |  THE LEG

FIGURE 7-263  Short fibula.

FIGURE 7-264  Accessory ossification center at the proximal end of the fibula.

FIGURE 7-265  Accessory ossicle at the superior end of the fibula in a 44-year-old man.

The Lower Extremity  |  THE LEG

599

PART 1  |  CHAPTER 7



FIGURE 7-266  Partitioned ossicle at the superior end of the fibula.

FIGURE 7-267  Normal lucency in the proximal fibular epiphysis in a 15-year-old girl.

FIGURE 7-268  Normal lucency of the fibular head simulating a cyst.

600

The Lower Extremity  |  THE LEG

FIGURE 7-269  Simulated discontinuity of the head of the fibula produced by the elongated configuration of the proximal end of the fibular head.

FIGURE 7-270  Unusual configuration of the proximal end of the fibula. FIGURE 7-271  Un-united accessory ossification center at the head of the fibula, simulating a fracture (m). Note also the bifid fabella (m 66).

FIGURE 7-272  Two examples of simulated discontinuity of the cortex of the fibula in lateral projection, which may be mistaken for a fracture.

The Lower Extremity  |  THE LEG

FIGURE 7-273  Simulated cyst of the head of the fibula as a result of the large amount of cancellous bone present in this area.

FIGURE 7-274  Unusual configuration of the proximal fibular metaphysis.

FIGURE 7-275  Developmental flangelike expansion of the neck of the fibula in a 15-year-old boy.

601

PART 1  |  CHAPTER 7



602

The Lower Extremity  |  THE LEG

FIGURE 7-276  Metaphyseal irregularity of the medial aspect of the fibular metaphysis in a 13-year-old boy. This is probably a “tug” lesion at the origin of the soleus muscle.

FIGURE 7-277  “Tug” lesions at the metaphysis of the proximal fibula at the origin of the soleus muscle, not to be mistaken for an osteochondroma.

The Lower Extremity  |  THE LEG

603

PART 1  |  CHAPTER 7



FIGURE 7-278  Example of marked “tug” lesions of the fibula in a 12-year-old long-distance swimmer. (Courtesy Dr. John Earwaker.)

604

The Lower Extremity  |  THE LEG

FIGURE 7-279  The soleal line represents a “tug” lesion at the origin of the soleus muscle. It should not be mistaken for periostitis. (Ref: Levine AH, et al: The soleal line: A cause of tibial pseudoperiostitis. Radiology 119:79, 1976.)

FIGURE 7-280  “Tug” lesions at both ends of the soleus muscle, producing a fibular spur (m) and the soleal line (m 66).

The Lower Extremity  |  THE LEG

605

PART 1  |  CHAPTER 7



A

C

B

D

FIGURE 7-281  Large soleal line. A, B, Radiographs. C, Short tau inversion recovery (STIR) coronal MR image. D, T1-weighted axial MR image.

606

The Lower Extremity  |  THE LEG

FIGURE 7-282  Prominence of the interosseous crest in the fibula simulating periostitis.

A

B FIGURE 7-283  Bilateral excrescences of the proximal fibular shafts.

The Lower Extremity  |  THE LEG

607

The Shafts of the Tibia and Fibula

FIGURE 7-284  Two examples of prenatal posterior bowing of the tibia and fibula, probably relative to fetal positions of the limbs in utero. (Ref: Silverman FN, Kuhn J: Caffey’s Pediatric X-Ray Diagnosis, 9th ed. St. Louis, Mosby, 1993.)

PART 1  |  CHAPTER 7



608

The Lower Extremity  |  THE LEG

FIGURE 7-285  Physiologic bowing in a 15-month-old child.

FIGURE 7-286  Physiologic bowing of the fibulae in a 19-month-old child, which should not be mistaken for plastic bowing fractures.

The Lower Extremity  |  THE LEG

609

PART 1  |  CHAPTER 7



A FIGURE 7-287  Physiologic bowing of the fibulae in an 11-year-old boy.

B

C

D

FIGURE 7-288  Physiologic bowing of the tibiae and fibulae in a 25-year-old-man. A, B, Right leg. C, D, Left leg.

FIGURE 7-289  Normal posterior bowing of the fibulae in an adult.

FIGURE 7-290  Spurious thickening of the lateral cortex of the tibia caused by slight external rotation of the leg. The density is caused by the fact that the anterior tibial crest comes progressively more into profile. (Ref: Silverman FN, Kuhn J: Caffey’s Pediatric X-Ray Diagnosis, 9th ed. St. Louis, Mosby, 1993.)

610

The Lower Extremity  |  THE LEG

FIGURE 7-291  Normal cortical irregularities of the shafts of the fibulae. Left, Frontal projections. Right, Lateral projections.

FIGURE 7-292  Localized bilateral symmetric undulations in the fibular cortex.

The Lower Extremity  |  THE LEG

611

PART 1  |  CHAPTER 7



A

B

FIGURE 7-293  A, Notchlike lesion in distal fibula seen in the oblique projection. Note similarity to a notchlike defect in the humerus (see Fig. 6–55). B, Lesion is not seen in the frontal projection.

FIGURE 7-294  Normal irregularities of the cortices of the tibia and fibula caused by ossification of the interosseous membrane.

612

The Lower Extremity  |  THE LEG

FIGURE 7-295  Simulated isolated periostitis of the tibia like those in Figure 7-294.

A

B

FIGURE 7-296  Two examples of vascular channels in tibia simulating fracture as seen in the Figure 7-295.

FIGURE 7-297  Two examples of juvenile benign cortical defects of the tibia. These lesions are common in the tibia and are of no clinical significance. (Ref: Silverman FN, Kuhn J: Caffey’s Pediatric X-Ray Diagnosis, 9th ed. St. Louis, Mosby, 1993.)

The Lower Extremity  |  THE LEG

613

PART 1  |  CHAPTER 7



FIGURE 7-298  Two additional examples of benign cortical defects of the tibia.

FIGURE 7-299  Two examples of healed juvenile benign cortical defects.

614

The Lower Extremity  |  THE LEG

FIGURE 7-300  Very dense healed benign cortical defect.

FIGURE 7-301  Large healed benign cortical defect of the fibula, an unusual site for this lesion.

The Lower Extremity  |  THE LEG

615

PART 1  |  CHAPTER 7



A

C

B

D

FIGURE 7-302  Juvenile benign cortical defect on plain films (A and B). Fat-saturated T2-weighted MR image (C), and T1-weighted MR image (D).

616

The Lower Extremity  |  THE LEG

FIGURE 7-303  Nutrient vascular channels of the fibula.

FIGURE 7-304  Nutrient channels of the fibula mistaken for fracture.

FIGURE 7-305  The nutrient channel of the tibia.

The Lower Extremity  |  THE LEG

The Distal Ends of the Tibia and Fibula

FIGURE 7-306  Normal metaphyseal irregularity of the tibia in a 14-year-old boy.

FIGURE 7-307  Normal bump in the medial cortex of the distal fibula, which may simulate a torus fracture, in a 2-year-old child.

FIGURE 7-308  Ringlike lesions of the distal fibula. These are probably similar in nature to those seen in the proximal end of the tibia (see Fig. 7-241) and are of no clinical significance.

617

PART 1  |  CHAPTER 7



The Lower Extremity  |  THE LEG

618

A

C

B

FIGURE 7-309  Films of a normal 10-year-old child. The physis may appear at different positions in the various projections and can be mistaken for an epiphyseal fracture. A, AP projection. B, Oblique projection. C, Lateral projection. (Ref: Chung J, Jaramillo D: Normal maturing distal tibia and fibula: Changes with age at MR imaging. Radiology 194:227, 1995.)

A

B FIGURE 7-310  The physis of the distal tibia may simulate a fracture. A, Frontal projection. B, Oblique projection.

The Lower Extremity  |  THE LEG

619

PART 1  |  CHAPTER 7



FIGURE 7-311  Normal localized angulation of the distal epiphyseal plate of the tibia in an 11-year-old boy (Kump’s hump).  (Ref: Kump WL: Vertical fracture of the distal tibial epiphysis. Am J Roentgenol Radium Ther Nucl Med 97:676, 1966.)

FIGURE 7-312  The epiphyseal impression illustrated in Figure 7-311 should not be mistaken for a fracture when seen in the lateral projection.

A

B

FIGURE 7-313  A, B, Two examples of normal localized depressions in the metaphyses of the distal fibula in 11-year-old boys (m). The angulation of the distal tibial epiphysis is also seen in B (m 66). (Ref: Ogden JA, McCarthy SM: Radiology of postnatal skeletal development. VIII: Distal tibia and fibula. Skeletal Radiol 10:209, 1983.)

620

The Lower Extremity  |  THE LEG

FIGURE 7-314  Occasionally the depression of the epiphyseal plate seen in Figures 7-311 and 7-313 may extend distally into the epiphysis rather than into the metaphysis.

FIGURE 7-315  Discordant closure of the distal tibial and fibular physes in an 11-year-old girl. These closure rates cannot be reliably used to exclude a Salter-Harris type I fracture of either bone. A, Frontal film. B, Oblique projection.

B A

FIGURE 7-316  Another example of discordant maturation between the tibia and the fibula in the same subject. A, Age 9 years. B, Age 12 years.

A

B

The Lower Extremity  |  THE LEG

621

PART 1  |  CHAPTER 7



FIGURE 7-317  Exaggeration of the normal notch on the anterior surface of the distal portion of the tibia.

FIGURE 7-318  Overlapping of shadows of tibia and fibula simulating fractures of the lateral malleoli.

FIGURE 7-319  Simulated fracture of the lateral malleolus by the epiphyseal line.

FIGURE 7-320  Normal offset of the distal fibular epiphysis, which might be mistaken for a fracture through the epiphyseal line.

622

The Lower Extremity  |  THE LEG

FIGURE 7-321  The fibular ossicle (m), a normal accessory ossification center, in a 12-year-old boy. In A, the ossicle is seen at the lateral aspect of the fibular metaphysis. In B, a large ossicle is visible at the lateral aspect of the epiphyseal line. These ossicles fuse after puberty and are often mistaken for fractures. A large os subfibulare is also present in A (m 66). (Ref: Silverman FN, Kuhn J: Caffey’s Pediatric X-Ray Diagnosis, 9th ed. St. Louis, Mosby, 1993.)

A

B

FIGURE 7-322  Another example of the fibular ossicle.

FIGURE 7-323  Three examples of fibular ossicles, all of which were misinterpreted and treated as fractures.

The Lower Extremity  |  THE LEG

623

PART 1  |  CHAPTER 7



A

B

FIGURE 7-324  Cleft distal tibial epiphysis seen only in the oblique projection. Such clefting may be seen in many locations in late childhood.

FIGURE 7-325  Cleft in the medial malleolus simulating a fracture in a 15-year-old boy.

FIGURE 7-327  Failure of closure of the medial malleolus in an adult.

FIGURE 7-326  Developmental vertical cleft in the epiphysis of the distal end of the tibia in a 10-year-old boy. (Courtesy Dr. P. Waibel.)

624

The Lower Extremity  |  THE LEG

FIGURE 7-328  Cleft tibial epiphysis on the lateral side in a 16-year-old boy.

FIGURE 7-329  Cleft distal fibular metaphyses in a 7-year-old boy.

The Lower Extremity  |  THE LEG

FIGURE 7-330  Bilateral metaphyseal defects in a 4-yearold boy, probably related to the metaphyseal defects seen in older children.

FIGURE 7-331  Same entity as noted in Figure 7-330, here seen in a 10-year-old boy.

FIGURE 7-332  Developmental fossae or cortical defects in the medial aspects of the distal fibulae at the insertion of the anterior tibiofibular ligament are of no clinical significance. (Ref: Ehara S, et al: Cortical defect of the distal fibula: Variant of ossification. Radiology 197:447, 1995.)

625

PART 1  |  CHAPTER 7



626

A

The Lower Extremity  |  THE LEG

B FIGURE 7-333  A, B, The normal fossae of the distal end of the fibulae.

FIGURE 7-334  Irregularity of mineralization of the medial edge of the distal tibial epiphysis in an 8-year-old child. This finding is similar to that seen in the distal femoral epiphysis.

PART 1  |  CHAPTER 7

FIGURE 7-335  Bilateral separate secondary ossification centers for the medial malleoli in an 8-year-old boy, which may be mistaken for fractures.

A

B

D

E

C

F

FIGURE 7-336  A through F, Normal irregular ossification of the tip of the medial malleolus (m) in adolescent children. In C, an ossicle is seen between the talus and the lateral malleolus, representing the os trochleae calcanei (m 66). (Ref: Ogden JA, McCarthy SM: Radiology of postnatal skeletal development. VIII: Distal tibia and fibula. Skeletal Radiol 10:209, 1983.)

628

The Lower Extremity  |  THE LEG

FIGURE 7-337  Bilateral multicentric ossification of the medial malleolus in a 9-year-old girl.

A

B

FIGURE 7-338  A, Developmental radiolucency in the medial malleolus in a 9-year-old boy secondary to the presence of a secondary ossification center. B, Follow-up film taken 4 months later shows closing of secondary ossification center.

FIGURE 7-339  Persistent irregular ossification of the medial malleolus in an adult.

The Lower Extremity  |  THE LEG

629

PART 1  |  CHAPTER 7



FIGURE 7-340  Large bilateral os subtibiale, an accessory ossification center that has persisted into adult life and is frequently mistaken for a fracture.

FIGURE 7-341  Large separate ossification center of the medial malleolus in a 14-year-old boy that was misdiagnosed as a fracture. A, AP projection. B, Oblique projection.

A

FIGURE 7-342  The os subtibiale. This is a rare accessory bone related to the posterior colliculus of the medial malleolus, as opposed to the more common os subtibiale, which is related to the anterior colliculus that forms the tip of the malleolus. (Coral AA: The radiology of skeletal elements in the subtibial region: Incidence and significance. Skeletal Radiol 16:298, 1987.)

B

630

The Lower Extremity  |  THE LEG

A

B

C

FIGURE 7-343  Unfused accessory ossification center of the distal tibia producing unusual appearance of the upper margin of the talus. A, Frontal projection. B, Oblique projection. C, Tomogram.

FIGURE 7-344  Bony flanges on the lateral aspects of the medial malleoli, which should not be mistaken for avulsion injuries.

The Lower Extremity  |  THE LEG

631

PART 1  |  CHAPTER 7



FIGURE 7-345  Normal band of density in the articular surface of the posterior malleolus.

FIGURE 7-346  Persistent accessory ossification center of the posterior malleolus.

FIGURE 7-347  Secondary ossification center of the distal end of the lateral malleolus should not be mistaken for fracture.

FIGURE 7-348  Secondary ossification center of the lateral aspect and distal end of the lateral malleolus in a 12-year-old girl.

632

The Lower Extremity  |  THE LEG

FIGURE 7-349  Large os subfibulare at the tip of the lateral malleolus with inset into the adjacent malleolus.

A

B

FIGURE 7-350  Examples of large os subfibulare. A, An 11-year-old boy. B, A 14-year-old boy. Ossicles in this location may be symptomatic in children. (Ref: Griffiths JD, Menelaus MB: Symptomatic ossicles of the lateral malleolus in children. J Bone Joint Surg Br 69:317, 1987.)

The Lower Extremity  |  THE LEG

FIGURE 7-351  Os subfibulare is seen only in oblique projection (A). B, Frontal projection.

A

B

FIGURE 7-352  Simulated fracture of the tip of the lateral malleolus caused by trabeculations. Note that the cortical margins are intact.

FIGURE 7-353  Os subfibulare (m) with deep fossa in distal end of the fibula (m 6).

633

PART 1  |  CHAPTER 7



634

The Lower Extremity  |  THE LEG

FIGURE 7-354  Large os subfibulare mistaken for a fracture. One can sometimes differentiate this ossicle from a fracture by mentally subtracting the ossicle from the fibula and determining whether the architecture of the fibula is correct without the additional osseous element.

FIGURE 7-355  Examples of os subfibulare that resemble fractures. Such ossicles are occasionally a source of pain. (Ref: Berg EE: The symptomatic os subfibulare. J Bone Joint Surg Am 173:1251, 1991.)

FIGURE 7-356  Scalelike secondary ossification centers that resemble fractures.

The Lower Extremity  |  THE LEG

635

PART 1  |  CHAPTER 7



FIGURE 7-357  Accessory ossification centers of the lateral malleolus in a 10-year-old boy that was treated as a fracture for 6 months.

FIGURE 7-358  Simulated fracture of the lateral malleolus produced by overlying soft tissue shadow of the Achilles tendon.

FIGURE 7-359  The os talotibiale, an accessory ossicle.

FIGURE 7-360  “Foramen” in the lateral malleolus, detected as an incidental finding.

636

The Lower Extremity  |  THE LEG

FIGURE 7-361  Lucency similar to that seen in Figure 7-360 here seen at the tip of the medial malleolus.

FIGURE 7-362  Stress views of a normal ankle demonstrate some lateral joint widening. This is subject to great variability, illustrating the need for comparison views of the opposite side.

FIGURE 7-363  Pseudotalar tilt produced by improper positioning of the foot at the time of filming. (Ref: Bigongiari LR: Pseudotibiotalar slant: A positioning artifact. Radiology 122:669, 1977.)

The Lower Extremity  |  THE FOOT

637

PART 1  |  CHAPTER 7



FIGURE 7-364  Osteoporosis may simulate permeative bone destruction in the elderly.

FIGURE 7-365  A nice example of the accessory soleus muscle.

THE FOOT The Tarsals THE ACCESSORY OSSICLES

FIGURE 7-366  Accessory skeletal elements as seen on an anteroposterior radiograph of the ankle joint. (Ref: Kohler A, Zimmer EA: Borderlands of the Normal and Early Pathologic Findings in Skeletal Roentgenology, 3rd ed. New York, Grune & Stratton, 1968.) 1. Accompanying shadow on the internal malleolus (patella malleoli) 2. Intercalary bone (or sesamoid) between the internal malleolus and the talus 3. Os subtibiale 4. Talus accessorius 5. Os sustentaculi 6. Os tibiale externum 7. Os retinaculi 8. Intercalary bone (or sesamoid) between the external malleolus and the talus 9. Os secundarius 10. Talus secundarius 11. Os trochleare calcanei 12. Os trigonum

638

The Lower Extremity  |  THE FOOT

FIGURE 7-367  The accessory bones of the foot (after Kohler). (Ref: Kohler A, Zimmer EA: Borderlands of the Normal and Early Pathologic Findings in Skeletal Roentgenology, 3rd ed. New York, Grune & Stratton, 1968.) The sesamoid bones are indicated by shaded circles. These ossicles are usually of no clinical significance, but their recognition is important in the differential diagnosis of fracture. (Ref: Zatzkin HR: Trauma of the foot. Semin Roentgenol 5:419, 1970.) 1. Os tibiale externum 2. Processus uncinatus 3. Os intercuneiforme 4. Pars peronea metatarsalia 5. Cuboides secundarium 6. Os peroneum 7. Os vesalianum 8. Os intermetatarseum 9. Os supratalare 10. Talus accessorius 11. Os sustentaculum 12. Os trigonum 13. Calcaneus secundarius 14. Os subcalcis 15. Os supranaviculare 16. Os talotibiale

FIGURE 7-368  The os talocalcanei. (Ref: Kohler A, Zimmer EA: Borderlands of the Normal and Early Pathologic Findings in Skeletal Roentgenology, 3rd ed. New York, Grune & Stratton, 1968.)

FIGURE 7-369  The talus secundarius (m). Secondary ossification centers are seen at the medial malleolus (m 66).

The Lower Extremity  |  THE FOOT

639

PART 1  |  CHAPTER 7



FIGURE 7-370  The talus accessorius.

FIGURE 7-371  The os supratalare.

FIGURE 7-373  Large os supratalare.

FIGURE 7-372  The os supratalare.

640

A

C

The Lower Extremity  |  THE FOOT

B

D FIGURE 7-374  A through D, Variable appearance of the os trigonum. The multicentric appearance in A might be mistaken for a fracture.

FIGURE 7-375  Unusually large partitioned os trigonum.

The Lower Extremity  |  THE FOOT

641

PART 1  |  CHAPTER 7



A

B FIGURE 7-376  Os trigonum in the oblique projection (A) may not be seen as an isolated entity in the lateral projection (B).

FIGURE 7-377  Low position of the os trigonum.

A

B

FIGURE 7-378  Unusual configuration of the os trigonum (A) that can also be seen in the AP projection (B).

642

The Lower Extremity  |  THE FOOT

FIGURE 7-379  Intercalary bone (or sesamoid) between the medial malleolus and the talus.

FIGURE 7-380  The os talotibiale.

A

B

FIGURE 7-381  A, B, The os sustentaculum. (Ref: Kohler A, Zimmer EA: Borderlands of the Normal and Early Pathologic Findings in Skeletal Roentgenology, 4th ed. New York, Thieme, 1993.)

The Lower Extremity  |  THE FOOT

643

PART 1  |  CHAPTER 7



A

B

FIGURE 7-382  Two accessory bones of the calcaneal tuberosity. A, Os subcalcus (m). An os supranaviculare is also present (m 66). (Ref: Kohler A, Zimmer EA: Borderlands of the Normal and Early Pathologic Findings in Skeletal Roentgenology, 3rd ed. New York, Grune & Stratton, 1968.) B, Accessory bone arising from the tip of the trochlear process on the lateral wall of the calcaneus, seen in oblique projection. (Ref: Silverman FN, Kuhn J: Caffey’s Pediatric X-Ray Diagnosis, 9th ed. St. Louis, Mosby, 1993.)

FIGURE 7-383  The calcaneus secundarius.

644

The Lower Extremity  |  THE FOOT

A

B FIGURE 7-384  A, B, Large calcaneus secondarius.

FIGURE 7-385  Two examples of the os supranaviculare. This ossicle is often confused with an avulsion fracture.

The Lower Extremity  |  THE FOOT

645

PART 1  |  CHAPTER 7



FIGURE 7-386  Bilateral os supranaviculare.

FIGURE 7-387  Large os supranaviculare.

FIGURE 7-389  Large, bilateral os tibiale externum.

FIGURE 7-388  Huge os supranaviculare having articulations with both the talus and navicular.

646

The Lower Extremity  |  THE FOOT

FIGURE 7-390  Bipartite os tibiale externum.

FIGURE 7-391  Multicentric os tibiale externum.

FIGURE 7-392  Partially fused os tibiale externum (accessory navicular).

The Lower Extremity  |  THE FOOT

647

PART 1  |  CHAPTER 7



FIGURE 7-393  Virtually complete fusion of the os tibiale externum to the navicular bone (cornuate navicular).

A

B FIGURE 7-394  A, B, Two examples of an unnamed ossicle adjacent to the navicular.

648

The Lower Extremity  |  THE FOOT

FIGURE 7-396  The os peroneum.

FIGURE 7-395  Unnamed ossicle below navicular.

FIGURE 7-397  Large, multicentric os peroneum.

The Lower Extremity  |  THE FOOT

649

PART 1  |  CHAPTER 7



FIGURE 7-398  Three examples of multicentric os peroneum.

FIGURE 7-399  Os peroneum may be high in position and superimposed on the cuboid.

650

The Lower Extremity  |  THE FOOT

FIGURE 7-400  Bipartite os peroneum simulating a fracture.

FIGURE 7-401  Os peroneum simulating partial coalition of the cuboid and calcaneus (m). Note the simulated fusion between the lateral cuneiform and third metatarsal (m 6 ).

A

B FIGURE 7-402  A, B, The os intercuneiform.

The Lower Extremity  |  THE FOOT

651

PART 1  |  CHAPTER 7



A

B FIGURE 7-403  A, B, Bilateral ossicles above midfoot.

FIGURE 7-404  Huge os vesalianum (see Fig. 7-537).

FIGURE 7-405  Huge os vesalianum fused to the base of the fifth metatarsal.

652

The Lower Extremity  |  THE FOOT

A

B FIGURE 7-406  A, B, Two examples of an unnamed element, probably in the peroneus longus tendon.

A

B

D

C

E

F

FIGURE 7-407  A through F, Six examples of the variable appearance of the os intermetatarseum. Note the accessory ossicle at the distal end in F.

The Lower Extremity  |  THE FOOT

653

THE TALUS

FIGURE 7-408  Os trigonum, which should not be mistaken for fracture of the posterior process of the talus. Symptoms related to the os trigonum are best delineated by MR imaging. (Ref: Karasick D, Schweitzer ME: The os trigonum syndrome: Imaging features. AJR Am J Roentgenol 166:125, 1996.)

FIGURE 7-409  Huge posterior process of the talus.

A

B

FIGURE 7-410  A, Os trigonum may be projected onto the talus and simulate a fracture. B, True lateral projection shows usual appearance of the os trigonum.

PART 1  |  CHAPTER 7



654

The Lower Extremity  |  THE FOOT

FIGURE 7-411  Multicentric os trigonum.

FIGURE 7-412  Os accessorium supracalcaneum seen prominently on the left and minimally on the right. This ossicle is separate from the posterior process of the talus and articulates with the posterosuperior margin of the calcaneus. (From Milgrom C, et al: Case report 341: Os accessorium supracalcaneum of the left hind foot [also present, but to a lesser extent, on the right]. Skeletal Radiol 15:150, 1986.)

FIGURE 7-413  Unnamed ossicle in posterior aspect of distal tibia.

The Lower Extremity  |  THE FOOT

655

PART 1  |  CHAPTER 7



FIGURE 7-414  Two examples of normal saucerlike depressions on the superior aspect of the talus. (Ref: Resnick D: Talar ridges, osteophytes and beaks: A radiologic commentary. Radiology 151:329, 1984.)

A

B

FIGURE 7-415  A, B, Irregular ossification of the dome of the talus in a 6-year-old child with no symptoms referable to the ankle.

656

The Lower Extremity  |  THE FOOT

B

A

FIGURE 7-416  A, B, Forme fruste of bipartite talus (see Fig. 7-435). (Ref: Kohler A, Zimmer EA: Borderlands of the Normal and Early Pathologic Findings in Skeletal Radiography, 4th ed. New York, Thieme, 1993.)

A

B

C

FIGURE 7-417  Simulated cyst of the talus produced by through projection of the narrow waist of the bone. A, B, Plain films. C, Tomogram.

FIGURE 7-418  Os supratalare.

The Lower Extremity  |  THE FOOT

657

PART 1  |  CHAPTER 7



A

B FIGURE 7-419  A, B, Large os supratalare.

FIGURE 7-420  Two examples of the talar beak, illustrating its varied appearance. This structure is a developmental variant that should not be confused with hypertrophic spurring seen adjacent to the talonavicular joint.

FIGURE 7-421  Two additional examples of the talar beak.

658

The Lower Extremity  |  THE FOOT

A

B

C FIGURE 7-422  A through C, Examples of large talar beaks with ossicles at the tip (Ref: Keats TE, Harrison RB: Hypertrophy of the talar beak. Skeletal Radiol 4:37, 1979.)

FIGURE 7-423  Simulated fractures of the talus produced by prominent trabeculae.

The Lower Extremity  |  THE FOOT

659

PART 1  |  CHAPTER 7



FIGURE 7-425  Unusual width of the subtalar joint simulating talocalcaneal dislocation produced by poor positioning for the lateral projection. Note the foreshortening of the talus in the vertical plane.

FIGURE 7-424  Simulated fracture of the talus produced by overlapping of the lateral malleolus and posterior process of the talus.

FIGURE 7-426  Simulated talocalcaneal coalition produced by improper positioning during filming. (Ref: Shaffer HA Jr, Harrison RB: Tarsal pseudocoalition: A positional artifact. J Can Assoc Radiol 31:236, 1980.)

A

B

FIGURE 7-427  A, Simulated talar dislocation produced by rotation. B, True lateral projection shows normal relationships.

660

The Lower Extremity  |  THE FOOT

FIGURE 7-428  Partially fused talus secundarius. FIGURE 7-429  Os sustentaculum tali on CT scan. Note the coalition on the left. The sustentaculi are accessory bones lodged at the posterior end of the sustentaculum tali, slightly to its superior side. (Ref: March HC, London RI: The os sustentaculi. Am J Roentgenol Radium Ther Nucl Med 76:1114, 1956.) This anomaly may be incorporated in an accessory joint between the sustentaculum tali and the talus. (Ref: Bloom RA, et al: The assimilated os sustentaculi. Skeletal Radiol 15:455, 1986.)

A

C

B

D

FIGURE 7-430  Large os tibiale externa may be confused with os sustentaculi, which are lower in position. A, B, Frontal projections. C, D, Lateral projections.

The Lower Extremity  |  THE FOOT

661

PART 1  |  CHAPTER 7



A

B

C FIGURE 7-431  Fossa on the superior aspect of the talus in A (m) may produce apparent abnormalities in the oblique projections (B and C; m 6).

FIGURE 7-432  Nutrient foramen of the talus.

662

The Lower Extremity  |  THE FOOT

A

C

B

FIGURE 7-433  A, Deep fossa on the superior aspect of the talus in an adult, producing apparent abnormalities in the frontal and oblique projections (B and C).

A

B

FIGURE 7-434  The fossa described in Figure 7-433, if deep, may simulate a destructive lesion in the oblique projection. A, Lateral projection. B, Oblique projection.

The Lower Extremity  |  THE FOOT

663

PART 1  |  CHAPTER 7



A

B

C FIGURE 7-435  Talus partitus, an unusual developmental anomaly in which the talus is partitioned. A, Radiograph of right ankle. B, Tomogram of right ankle. C, Similar but less marked appearance of the left talus. (Ref: Schreiber A et al: Talus partitus: A case report. J Bone Joint Surg Br 67:430, 1985.) (Courtesy of Dr. L.W. Bassett.)

664

The Lower Extremity  |  THE FOOT

FIGURE 7-436  Some unusually prominent anterior processes of the talus, which should not be confused with the degenerative spurs that develop at the articulation secondary to tarsal coalition.

The Lower Extremity  |  THE FOOT

665

PART 1  |  CHAPTER 7



FIGURE 7-437  Unusual configuration of the distal end of the talus, with an accessory ossicle at its distal end.

B

A FIGURE 7-438  Partial coalition between the talus and navicular. A, AP projection. B, Lateral projection.

666

A

The Lower Extremity  |  THE FOOT

B FIGURE 7-439  A, B, Unusual configuration of the talus and navicular seen bilaterally in an 11-year-old child.

THE CALCANEUS

A

B FIGURE 7-440  A, B, Bilateral calcaneal hypoplasia in an 11⁄2-year-old child.

The Lower Extremity  |  THE FOOT

667

PART 1  |  CHAPTER 7



A

B

C

D

E

FIGURE 7-441  Variations in appearance of double ossification centers for the body of the calcaneus. This entity is seen in infants with bone dysplasias and occasionally in infants with no other obvious abnormality. A, A newborn with cleft center of calcaneus. B, A 2-year-old child with two well-defined centers of ossification. C through E, Fusing duplicate centers.

668

The Lower Extremity  |  THE FOOT

FIGURE 7-442  Double ossification centers for the calcaneus with irregular mineralization.

A

B FIGURE 7-443  A, B, Striking irregular patterns of ossification of the calcaneus seen bilaterally in a 2-year-old child.

FIGURE 7-444  Closing bilateral duplicate ossification centers of the calcaneus.

The Lower Extremity  |  THE FOOT

669

PART 1  |  CHAPTER 7



A

B

C FIGURE 7-445  Irregular lucency in midportion of calcaneus shown on lateral radiograph (A) as well as gradient echo T2-weighted (B) and T1-weighted (C) MR images. The lesion probably represents a remnant of the divided ossification centers of early life.

670

The Lower Extremity  |  THE FOOT

A

B

C

D FIGURE 7-446  A through D, Four examples of transient developmental calcaneal spurs in infants. Such spurs represent a variation in growth and disappear by age 1 year. A, B are films of the same child. (Refs: Robinson HM: Symmetrical reversed plantar calcaneal spurs in children. Radiology 119:187, 1976; van Wiechen PJ: Reversed calcaneal spurs in children: A normal variant? Skeletal Radiol 16:17, 1987.)

The Lower Extremity  |  THE FOOT

671

PART 1  |  CHAPTER 7



B

A

C

D

FIGURE 7-447  A through D, Four examples of simulated calcaneal cyst caused by the normal arrangement of the trabecular pattern in this area. The presence of the nutrient channel within the cyst, as in A, is useful in identifying the area of radiolucency as a pseudocyst. This variant is confused with true cyst of the calcaneus. (Ref: Keats TE: The calcaneal nutrient canal. Skeletal Radiol 3:329, 1979.)

672

The Lower Extremity  |  THE FOOT

A

B FIGURE 7-448  Calcaneal pseudocyst. The problem of distinguishing the pseudocyst (A) from a true cyst is most simply solved if one uses the axial projection of the calcaneus, on which the pseudocyst will not be apparent (B).

FIGURE 7-449  The calcaneal pseudocyst seen in axial CT projection.

The Lower Extremity  |  THE FOOT

673

PART 1  |  CHAPTER 7



B

A FIGURE 7-450  The calcaneal pseudocyst on MR image. A, T1-weighted image. B, Gradient echo T2-weighted image.

FIGURE 7-451  Unusual pseudocyst of the calcaneus. The Harris view showed no abnormality.

674

The Lower Extremity  |  THE FOOT

FIGURE 7-452  Normal variations in appearance of the growing calcaneus in adolescence. The irregularity of the calcaneal tuberosity before fusion of the secondary ossification center and the density and fragmentation of the secondary ossification center are normal manifestations of growth.

FIGURE 7-453  “Fracture” of the calcaneal tuberosity simulated by the apophysis in the oblique projection of the foot. This appearance is seen before the calcaneal apophysis is closed and is produced by projection of the caudal tip of the apophysis into the soft tissues, as illustrated in the oblique view (A). This appearance is not seen in the lateral projection (B). (From Keats TE: Four normal anatomic variations of importance to radiologists. Am J Roentgenol Radium Ther Nucl Med 78:89, 1957.)

A

B

The Lower Extremity  |  THE FOOT

675

PART 1  |  CHAPTER 7



FIGURE 7-454  Two more examples of the tip of the ossification center of the calcaneal tuberosity, seen in oblique projection.

FIGURE 7-455  Appearance of the calcaneal apophyses in an adolescent. This projection may show centers of ossification that are not visible in the lateral projection.

FIGURE 7-456  Simulated fractures of the calcaneus produced by the unfused secondary ossification center for the calcaneal tuberosity.

676

The Lower Extremity  |  THE FOOT

FIGURE 7-457  Failure of union of a portion of the calcaneal apophysis in an adult. FIGURE 7-458  Shelflike configuration of the superior aspect of the calcaneus, not to be mistaken for an erosion.

FIGURE 7-459  A more extreme example of partial failure of a portion of the calcaneal apophysis.

A

B

FIGURE 7-460  A, B, Secondary ossification center at the tip of the trochlear process on the lateral wall of the calcaneus, which is seen well only in the oblique projection (m). B, The trochlear process may be so prominent, as in this case, as to suggest an exostosis (m 66).

The Lower Extremity  |  THE FOOT

677

PART 1  |  CHAPTER 7



FIGURE 7-461  The trochlear process of the calcaneus, not to be mistaken for an exostosis.

A

B FIGURE 7-462  A, B, The trochlear process of the calcaneus producing an apparent lucency in the lateral projection (B).

678

The Lower Extremity  |  THE FOOT

FIGURE 7-463  Os subcalcis, not an avulsion fracture.

FIGURE 7-464  Developmental foramina in the calcaneal tuberosities, seen in oblique projection.

FIGURE 7-465  Nutrient channel of the calcaneus (m) and a fossa (m 6 ), which might be mistaken for an abnormality.

FIGURE 7-466  Calcaneus secundarius should not be mistaken for a fracture of the anterior process of the calcaneus.

The Lower Extremity  |  THE FOOT

679

PART 1  |  CHAPTER 7



FIGURE 7-467  Three examples of simulated fractures of the superior margin of the calcaneus produced by the sustentaculum tali.

FIGURE 7-468  Simulated fractures produced by the sustentaculum tali.

680

The Lower Extremity  |  THE FOOT

FIGURE 7-469  Simulated cyst produced by the sustentaculum tali.

FIGURE 7-470  Incomplete osseous bridge between the calcaneus and the cuboid.

FIGURE 7-471  Calcaneal cuboid coalition.

The Lower Extremity  |  THE FOOT

681

PART 1  |  CHAPTER 7



FIGURE 7-472  Prominent trabeculation in the calcaneus, mistaken for a stress fracture. This is a rather common finding.

A

C

B

FIGURE 7-473  A, Simulated lesion in the calcaneus produced by prominent trabeculation, seen bilaterally on axial CT scans (B and C).

A

B

C

FIGURE 7-474  A, Simulated fracture in axial projection of the calcaneus, produced by the same mechanism as in Figure 7-473. Demonstrated by axial CT scans of both calcanei (B and C).

682

The Lower Extremity  |  THE FOOT

FIGURE 7-475  Attachment site of the long plantar ligament, not to be confused with a spur or exostosis. FIGURE 7-476  Calcification in the long plantar ligament in a healthy 24-year-old man, a finding of no clinical significance.

FIGURE 7-477  Vascular calcification in the plantar soft tissues and exostosis-like protrusion from the plantar surface of the calcaneus, probably related to the long plantar ligament.

The Lower Extremity  |  THE FOOT

THE TARSAL NAVICULAR

FIGURE 7-478  Normal ossification of the navicular from duplicate irregular centers in a 6-year-old.

683

PART 1  |  CHAPTER 7



684

The Lower Extremity  |  THE FOOT

FIGURE 7-479  Duplicate ossification centers of the navicular of different sizes.

FIGURE 7-480  Normal irregular ossification of the naviculars and first cuneiforms in an 8-year-old child.

FIGURE 7-481  Bilateral irregular ossification of the tarsal naviculars in an 8-year-old boy. Note also the asymmetric appearance of the calcaneal apophyses.

The Lower Extremity  |  THE FOOT

685

PART 1  |  CHAPTER 7



FIGURE 7-482  Irregular ossification of the tarsal navicular in a 5-year-old boy that was mistaken for Kohler’s disease.

FIGURE 7-483  Developmental irregularity of the medial aspect of the naviculars in a 12-year-old boy.

686

The Lower Extremity  |  THE FOOT

FIGURE 7-484  Incomplete fusion of duplicate ossification centers for the navicular in an 8-year-old boy simulating a fracture.

FIGURE 7-485  Bilateral bipartite tarsal naviculars in an adult. (Refs: Kohler A, Zimmer EA: Borderlands of Normal and Early Pathologic Findings in Skeletal Radiography, 4th ed. New York, Thieme, 1993; Shawdon A, et al: The bipartite tarsal navicular bone: Radiographic and computed tomography findings. Australas Radiol 39:192, 1995.)

The Lower Extremity  |  THE FOOT

687

PART 1  |  CHAPTER 7



A

B

FIGURE 7-486  Abortive bipartite navicular. A, AP projection. Note multicentric os tibiale externum (m). B, Lateral projection (see Fig. 7-488).

FIGURE 7-487  Unusual configuration of the navicular similar to one in Figure 486.

688

The Lower Extremity  |  THE FOOT

A

B

C FIGURE 7-488  Bipartite navicular. A, Frontal view. B, Lateral view. C, Frontal tomogram.

A

B FIGURE 7-489  A, B, Partial coalition of the navicular and the first cuneiform.

The Lower Extremity  |  THE FOOT

689

PART 1  |  CHAPTER 7



FIGURE 7-491  The os tibiale externum may be mistaken for a fracture. This variant may occasionally be symptomatic. (Refs: Lawson JP, et al: The painful accessory navicular. Skeletal Radiol 12:250, 1984 Grogan DP, et al: The painful accessory navicular: A clinical and histopathological study. Foot Ankle 10:164, 1989.)

FIGURE 7-490  The cornuate navicular.

FIGURE 7-492  Huge os tibiale externum.

690

The Lower Extremity  |  THE FOOT

B

A

FIGURE 7-493  A, B, Two examples of multicentric ossification of the os tibiale externum.

FIGURE 7-495  Fusion of an os tibiale externum to the navicular. FIGURE 7-494  Cornuate navicular with huge os tibiale externum.

The Lower Extremity  |  THE FOOT

691

PART 1  |  CHAPTER 7



FIGURE 7-496  Configuration of the naviculars suggesting complete incorporation of the os tibiale externum (cornuate navicular).

FIGURE 7-497  Unusual bilateral os tibiale externum.

A

B

C

FIGURE 7-498  A, B, Os tibiale externum originally diagnosed as a fracture because of its presence on one side only. C, Tomogram confirming nonfracture.

692

The Lower Extremity  |  THE FOOT

FIGURE 7-500  This small spur at the posterior superior aspect of the navicular is seen in many young people and is not an indication of degenerative arthritis.

FIGURE 7-499  Partial fusion of the os tibiale externum that was mistaken for a fracture.

FIGURE 7-501  Partial incorporation of the os supranaviculare, which might be mistaken for an avulsion fracture.

A

B FIGURE 7-502  A, B, Bilateral total incorporation of the os supranaviculare.

The Lower Extremity  |  THE FOOT

693

PART 1  |  CHAPTER 7



FIGURE 7-503  Normal irregularity of the joint margins of the navicular and cuboid in oblique projection. This entity should not be mistaken for a manifestation of arthritis.

A

B FIGURE 7-504  A, B, Unusual configuration of the superior aspect of the navicular in young subjects.

694

The Lower Extremity  |  THE FOOT

THE CUNEIFORMS

A

B

C D

E

FIGURE 7-505  A through C, Normal irregular ossification of the tarsal bones of the right foot in a 4-year-old child. Note the bipartite ossification of calcaneus and talus and the irregularity of the cuneiforms. D, Right foot at age 6 years. Note the residual irregularities in the posterior aspect of the talus. E, Left foot at age 6 years. Note some persistence of the bifid calcaneus.

The Lower Extremity  |  THE FOOT

695

PART 1  |  CHAPTER 7



FIGURE 7-506  Bilateral developmental tarsal irregularity in a 6-year-old boy. Such irregularities disappear with growth.

FIGURE 7-507  Irregular ossification of the cuneiforms in a 4-year-old boy.

696

The Lower Extremity  |  THE FOOT

FIGURE 7-508  Irregular ossification of the first cuneiforms in a 6-year-old boy.

FIGURE 7-509  Bilateral accessory ossification centers at the tips of the first cuneiforms in a 9-year-old boy.

The Lower Extremity  |  THE FOOT

697

PART 1  |  CHAPTER 7



A

B

C

D FIGURE 7-510  A, B, Central densities within the first cuneiform of a 3-year-old boy. C, D, One year later.

698

The Lower Extremity  |  THE FOOT

FIGURE 7-511  Bilateral bipartite first cuneiforms in a 6-year-old boy. (Ref: Kohler A, Zimmer EA: Borderlands of the Normal and Early Pathologic Findings in Skeletal Roentgenology, 4th ed. New York, Thieme, 1993.)

FIGURE 7-512  Bilateral bipartite first cuneiforms in a 6-year-old child.

The Lower Extremity  |  THE FOOT

699

PART 1  |  CHAPTER 7



FIGURE 7-513  Bipartite first cuneiform on the patient’s left foot (m). The right foot shows an os tibiale externum (m 66). The bipartite first cuneiform is more commonly divided into dorsal and plantar segments. (Ref: Kohler A, Zimmer EA: Borderlands of the Normal and Early Pathologic Findings in Skeletal Roentgenology, 4th ed. New York, Thieme, 1993.)

FIGURE 7-514  The os intercuneiform.

FIGURE 7-515  Supernumerary bone arising from the left first cuneiform (m). On the right foot, it is represented by an osseous protuberance (m 66). (Ref: Rao B: Supernumerary toe arising from the medial cuneiform: A case report. J Bone Joint Surg 61:308, 1979.) FIGURE 7-516  Supernumerary bones arising from the first cuneiform.

700

The Lower Extremity  |  THE FOOT

FIGURE 7-517  Simulated fractures produced by overlapping shadows of the cuneiforms.

A

B

FIGURE 7-518  A, B, Two examples of simulated subluxation of the calcaneus from the cuboid resulting from foot positioning. Both cases proved normal on CT scan.

The Lower Extremity  |  THE FOOT

701

PART 1  |  CHAPTER 7



FIGURE 7-519  Left, Simulated fusion between the base of the third metatarsal and the lateral cuneiform. Right, Situation clarified by filming in greater obliquity.

FIGURE 7-520  Normal spacing between the first and second cuneiforms (m), not to be confused with traumatic alteration. The groove on the medial surface is also normal (m 66).

702

The Lower Extremity  |  THE FOOT

FIGURE 7-521  Bilateral simulated Lisfranc dislocations of the base of the first metatarsal that do not follow the normal alignment with the first and second cuneiforms.

FIGURE 7-522  Another example of the entity shown in Figure 7-521, seen here bilaterally.

The Lower Extremity  |  THE FOOT

703

PART 1  |  CHAPTER 7



FIGURE 7-524  Contour alteration of the third cuneiform, which was mistaken for a fracture.

FIGURE 7-523  Normal fossa between the second and third cuneiforms.

FIGURE 7-525  Groove for the tibialis anterior tendon, not an erosion.

704

The Lower Extremity  |  THE FOOT

FIGURE 7-526  Normal radiolucencies seen in and between the cuneiforms.

FIGURE 7-527  Prominent fossa on lateral aspect of first cuneiform.

The Lower Extremity  |  THE FOOT

THE CUBOID

A

B

FIGURE 7-528  A, Normal irregularity of the posterior aspect of the cuboid in a 2-year-old child with a fracture of the calcaneus. B, Gradient echo T2*-weighted MR image.

FIGURE 7-529  Congenital fusion of the cuboid and the third cuneiform.

705

PART 1  |  CHAPTER 7



706

The Lower Extremity  |  THE FOOT

A

B

C

D

FIGURE 7-530  Simulated cysts in the cuboids of a 12-year-old boy in lateral projections (A and B). AP projections (C and D) show no abnormality.

The Lower Extremity  |  THE FOOT

707

PART 1  |  CHAPTER 7



A

B FIGURE 7-531  The same entity as shown in Figure 7-530, here in a 10-year-old child (A) and an 11-year-old child (B).

FIGURE 7-532  Fossae in the posterior aspect of the cuboid, which should not be mistaken for erosions.

FIGURE 7-533  Accessory bone of the lateral aspect of the distal end of the cuboid.

FIGURE 7-534  Groove for the peroneus longus tendon.

708

The Lower Extremity  |  THE FOOT

FIGURE 7-535  Sclerotic groove for the peroneus longus tendon.

FIGURE 7-536  Overlapping shadows of cuboid and cuneiforms, producing an unusual shadow bilaterally.

The Lower Extremity  |  THE FOOT

709

The Metatarsals

FIGURE 7-537  Os vesalianum, which lies in the peroneus brevis tendon. (Ref: Smith AD, et al: The os vesalianum: An unusual cause of lateral foot pain. Orthopedics 7:86, 1984.)

FIGURE 7-538  Knoblike expansions of the lateral aspects of the first metatarsals in a 3-year-old child.

PART 1  |  CHAPTER 7



710

The Lower Extremity  |  THE FOOT

FIGURE 7-540  Developmental notch in the distal end of the first metatarsal in a young child.

FIGURE 7-539  The same entity as described in Figure 7-538, here in an 18-month-old child.

FIGURE 7-541  Accessory ossification center at the distal end of the first metatarsal.

The Lower Extremity  |  THE FOOT

711

PART 1  |  CHAPTER 7



FIGURE 7-542  Accessory ossification centers in the distal ends of the first metatarsals in an 8-year-old boy.

FIGURE 7-543  Bilateral symmetric accessory ossification centers at the distal ends of the first metatarsals in an 11-year-old boy (m). Note clefts in the distal ends of the proximal phalanges as well (m 6).

FIGURE 7-544  Accessory ossification center of the distal end of the first metatarsal (m) in an 8-year-old boy with an epiphyseal spur (m 6 ).

712

The Lower Extremity  |  THE FOOT

FIGURE 7-545  Partial closure of the pseudoepiphysis at the head of the first metatarsal in a 6-year-old girl, which may simulate a fracture.

FIGURE 7-546  Closed accessory ossification center of distal end of the first metatarsal (m) with an epiphyseal spur (m 6).

FIGURE 7-547  The dorsofibular process of the head of the first metatarsal, a normal variant. (Ref: Fischer E: Der dorsofibulare Fortsatz am Kopf des l Metatarsale, eine ossare variante. Radiologe 28:45, 1988.)

FIGURE 7-548  Exaggeration of normal fossa in the head of the first metatarsal.

The Lower Extremity  |  THE FOOT

713

PART 1  |  CHAPTER 7



FIGURE 7-549  Accessory ossification centers at the bases of the second, third, and fourth metatarsals. These are of no clinical significance.

FIGURE 7-550  Accessory ossification centers at the bases of the second to fifth metatarsals, with partial fusion, in a 4-year-old boy.

FIGURE 7-552  Duplication of the ossification center of the base of the first metatarsal.

FIGURE 7-551  Accessory ossification centers at the bases of metatarsals two through five (m) and an accessory center at the distal end of the first metatarsal (m 6 ) in a 12-year-old boy.

714

The Lower Extremity  |  THE FOOT

FIGURE 7-553  Duplication of the ossification center of the head of the third metatarsal, not a fracture.

FIGURE 7-554  Duplication of the ossification centers of the heads of the third, fourth, and fifth metatarsals.

FIGURE 7-555  The normal apophysis of the tuberosity of the base of the fifth metatarsal, which resembles a fracture. Most fractures of this area are transverse rather than longitudinal.

The Lower Extremity  |  THE FOOT

715

PART 1  |  CHAPTER 7



FIGURE 7-556  Multicentric ossification centers of the tuberosities of the fifth metatarsals in a 12-year-old girl simulating fractures.

FIGURE 7-557  The lateral position of the apophysis of the base of the fifth metatarsal in the oblique projection should not be misconstrued as an avulsion injury.

716

The Lower Extremity  |  THE FOOT

FIGURE 7-558  Irregular mineralization of the apophysis of the base of the fifth metatarsal.

FIGURE 7-559  The fusing apophysis at the base of the fifth metatarsal may simulate a fracture in the frontal projection.

FIGURE 7-560  Closing apophysis that might be mistaken for a fracture at the base of the fifth metatarsal in an 11-year-old boy.

The Lower Extremity  |  THE FOOT

717

PART 1  |  CHAPTER 7



FIGURE 7-561  The apophysis at the base of the fifth metatarsal (m) plus a fracture (m 6 ) in a 13-year-old girl.

FIGURE 7-562  Four examples of failure of union of the apophysis of the base of the fifth metatarsal in adults.

718

The Lower Extremity  |  THE FOOT

FIGURE 7-563  Asymmetric closure of the apophyses at the bases of the fifth metatarsals in a 20-year-old man.

FIGURE 7-564  Closing apophysis at the base of the fifth metatarsal (m). Note how the trabeculations of the bone appear to line up in continuity with the apophyseal plate and simulate a fracture of the base (m 6 ).

FIGURE 7-565  Note the horizontal trabeculations in the base of the fifth metatarsal. It is these lines that create the illusion of a transverse fracture, as shown in Figure 7-564.

The Lower Extremity  |  THE FOOT

719

PART 1  |  CHAPTER 7



FIGURE 7-566  Apophysis at the tip rather than at the side of the base of the fifth metatarsal in a 14-year-old boy. (Ref: Dameron JB: Fractures and anatomical variation of the proximal portion of the fifth metatarsal. J Bone Joint Surg Am 57:788, 1975.)

FIGURE 7-567  Bilateral transverse apophyses at the bases of the fifth metatarsals in an 8-year-old girl.

720

The Lower Extremity  |  THE FOOT

A

B

C

D FIGURE 7-568  Films of a 13-year-old boy. A through C, A transverse fracture may simulate the kind of secondary center illustrated in Figure 7-567. D, Comparison view of the opposite side shows normal appearance, clarifying the problem.

The Lower Extremity  |  THE FOOT

721

PART 1  |  CHAPTER 7



FIGURE 7-569  Duplication anomaly of the fifth metatarsal with nonunion of the basal apophysis.

A

B FIGURE 7-570  A, B, Os vesalianum fused to the base of the fifth metatarsal.

FIGURE 7-571  Spur at the base of the fifth metatarsal.

The Lower Extremity  |  THE FOOT

722

A

B

FIGURE 7-572  Metatarsus adductus is physiologic in many infants and will correct spontaneously with weight-bearing. A, Age 4 months. B, Age 16 months. (Ref: Berg EE: A reappraisal of metatarsus adductus and skewfoot. J Bone Joint Surg Am 68:1185, 1986.)

FIGURE 7-573  Normal clefts seen at the bases of the metatarsals.

The Lower Extremity  |  THE FOOT

723

PART 1  |  CHAPTER 7



A

B

FIGURE 7-574  A, B, Unusual bilateral articulations between the bases of first and second metatarsals.

FIGURE 7-575  Another example of the anomalous articulation between the base of the first metatarsal and second metatarsal.

724

The Lower Extremity  |  THE FOOT

FIGURE 7-576  Normal irregularity of the epiphyseal line at the base of the first metatarsal in an adolescent boy, which should not be mistaken for evidence of a fracture.

FIGURE 7-577  Another example of the entity seen in the Figure 7-576.

The Lower Extremity  |  THE FOOT

725

PART 1  |  CHAPTER 7



FIGURE 7-578  Three examples of normal irregularities of the bases of the second, third, and fourth metatarsals, evident in oblique projection.

A

B FIGURE 7-579  A, B, Bilateral fossae at the base of the fourth metatarsal that are not to be confused with erosions.

726

The Lower Extremity  |  THE FOOT

FIGURE 7-580  Simulated torus fracture produced by the tuberosity at the base of the second metatarsal in a 13-year-old girl.

FIGURE 7-581  Developmental spur at the base of the third metatarsal.

FIGURE 7-582  Two examples of increase in size and cortical thickness of the shaft of the second metatarsal, seen in patients with short first metatarsals. This is apparently a compensatory weight-bearing mechanism.

The Lower Extremity  |  THE FOOT

727

PART 1  |  CHAPTER 7



A

B FIGURE 7-583  A, B, Two examples of nonsignificant cortical thickenings of the metatarsals seen in the aged.

FIGURE 7-584  A striking example of the entity seen in Figure 7-583.

728

The Lower Extremity  |  THE FOOT

FIGURE 7-585  Two examples of the nutrient channels for the metatarsals.

FIGURE 7-586  Developmental cleft at the base of the fourth metatarsal in a young child.

FIGURE 7-587  A, Entity similar to that illustrated in Figure 7-586. This adolescent girl was examined for minor trauma. A cleft is seen in the proximal shaft of the fourth metatarsal. B, Follow-up film taken 1 month later shows no change. The patient was asymptomatic.

A

B

The Lower Extremity  |  THE FOOT

729

PART 1  |  CHAPTER 7



FIGURE 7-588  Anomalous articulation between the third and fourth metatarsals.

FIGURE 7-589  Os intermetatarseum. This accessory bone appears on the dorsal aspect of the foot and is variable in size and shape. It may be separate or may be attached to the base of the first metatarsal or, as seen here, the second metatarsal. (Ref: Kohler A, Zimmer EA: Borderlands of Normal and Early Pathologic Findings in Skeletal Radiography, 4th ed. New York, Thieme, 1993.)

730

The Lower Extremity  |  THE FOOT

FIGURE 7-590  Bilateral os intermetatarseum.

FIGURE 7-591  Variation in configuration of the os intermetatarseum.

FIGURE 7-592  Fossa in the base of the second metatarsal secondary to the presence of a small os intermetatarseum.

The Lower Extremity  |  THE FOOT

731

PART 1  |  CHAPTER 7



FIGURE 7-593  Os intermetatarseum (m) and developmental fusion between the fourth and fifth metatarsals (m 6).

FIGURE 7-594  Unusual os intermetatarseum.

The Lower Extremity  |  THE FOOT

732

FIGURE 7-595  Bipartite os intermetatarseum.

A

B FIGURE 7-596  A, B, Bilateral os intermetatarseum seen in lateral projections of the feet.

The Lower Extremity  |  THE FOOT

733

PART 1  |  CHAPTER 7



FIGURE 7-597  An unusual os intermetatarseum.

FIGURE 7-598  Flat configuration of the head of the second metatarsal and resultant widening of the joint space should not be misconstrued as evidence of aseptic necrosis (Freiberg’s disease). (Ref: Jensen EL, de Carvalho A: A normal variant simulating Freiberg’s disease. Acta Radiol 28:85, 1987.)

734

The Lower Extremity  |  THE FOOT

FIGURE 7-599  Left, Deep cleft in the head of the fifth metatarsal in a 23-year-old woman seen in oblique projection. Right, Frontal projection shows unusual configuration of the head of the metatarsal.

FIGURE 7-600  The “lesser knob” at the head of the fifth metatarsal. FIGURE 7-601  The “great knob of Keats” in the first metatarsal (see Fig. 6–290).

The Lower Extremity  |  THE FOOT

735

PART 1  |  CHAPTER 7



FIGURE 7-602  Unusual fifth metatarsal with attempted formation of an additional phalanx.

FIGURE 7-603  Exaggeration of the normal curvature of the fifth metatarsal.

736

The Lower Extremity  |  THE FOOT

FIGURE 7-604  Developmentally short fifth metatarsal.

The Lower Extremity  |  THE FOOT

737

PART 1  |  CHAPTER 7



A

B FIGURE 7-605  A, Developmentally short fifth metatarsals in a 6-year-old boy with delayed appearance of the epiphysis. B, At age 10 years, the appearance is now normal. (Courtesy Drs. Seymour and A.G. MacEachern.)

738

The Lower Extremity  |  THE FOOT

FIGURE 7-606  Developmentally short fourth and fifth metatarsals.

FIGURE 7-607  Normal lucency in the medial aspect of the head of the fifth metatarsal that should not be mistaken for an erosion.

FIGURE 7-608  Axial projection of the shafts of the proximal phalanx simulating a cyst in the head of the fifth metatarsal.

FIGURE 7-609  Duplication of the fourth metatarsal.

The Lower Extremity  |  THE FOOT

739

PART 1  |  CHAPTER 7



FIGURE 7-611  Healed benign cortical deficit of the third metatarsal. FIGURE 7-610  Supernumerary metatarsal between the fourth and fifth metatarsals.

A

B

FIGURE 7-612  A, B, An additional example of a healed benign cortical defect of the metatarsal.

740

The Lower Extremity  |  THE FOOT

The Sesamoid Bones

FIGURE 7-613  The sesamoid bones of the foot. (Refs: Kohler A, Zimmer EA: Borderlands of the Normal and Early Pathologic Findings in Skeletal Roentgenology, 3rd ed. New York, Grune & Stratton, 1968; Potter G, et al: The hallux sesamoids revisited. Skeletal Radiol 21:437, 1992.)

FIGURE 7-614  Multiple sesamoids of both feet.

FIGURE 7-615  Multipartite sesamoid bone simulating a comminuted fracture.

FIGURE 7-616  Fissurelike lucencies in the lateral sesamoids of the first toes simulating fractures.

The Lower Extremity  |  THE FOOT

741

PART 1  |  CHAPTER 7



FIGURE 7-617  Frontal and lateral projections of a bipartite sesamoid bone of the first toe, with equal size of the members. (Ref: Feldman F, et al: The case of the wandering sesamoid and other sesamoid afflictions. Radiology 96:275, 1970.)

FIGURE 7-618  Developing sesamoids in a 12-year-old boy, seen in lateral projection.

FIGURE 7-619  Three examples of sesamoids at the interphalangeal joint of the first toe.

742

The Lower Extremity  |  THE FOOT

FIGURE 7-620  Sesamoids at the second and fifth metatarsal heads.

FIGURE 7-621  Bony ossicles, resembling sesamoids, on the dorsal aspects of both interphalangeal joints of the great toes in a 36-year-old woman.

FIGURE 7-622  Bipartite sesamoid of the first toe, with unequal size of the members.

The Lower Extremity  |  THE FOOT

743

PART 1  |  CHAPTER 7



FIGURE 7-623  Symmetric oval bipartite sesamoid of the first toe.

FIGURE 7-624  Tripartite sesamoid of the first toe.

744

The Lower Extremity  |  THE FOOT

FIGURE 7-626  Isolated sesamoids at the head of the fifth metatarsal.

FIGURE 7-625  Sesamoid at the fifth metatarsophalangeal joint.

FIGURE 7-628  Isolated sesamoid at the head of the third metatarsal.

FIGURE 7-627  Bipartite sesamoid at the head of the fifth metatarsal.

The Lower Extremity  |  THE FOOT

745

PART 1  |  CHAPTER 7



FIGURE 7-629  Unusual sesamoid at the head of the first metatarsal.

The Toes

FIGURE 7-630  Accessory ossification centers at the base of the distal phalanx of the first toe in a 10-year-old boy.

746

The Lower Extremity  |  THE FOOT

A

B

C

FIGURE 7-631  Divided epiphysis at the base of the proximal phalanx of the first toe (not a fracture). A, A 3-year-old boy. B, An 11-year-old boy. C, A 13-year-old boy. (Ref: Lyritis C: Developmental disorders of the proximal epiphysis of the hallux. Skeletal Radiol 10:250, 1983.)

FIGURE 7-632  Cleft in the ossification center at the base of the proximal phalanx of the first toe, in the plane opposite to that in Figure 7-631, in a 16-year-old boy.

The Lower Extremity  |  THE FOOT

747

PART 1  |  CHAPTER 7



B

A

C

D

FIGURE 7-633  A, B, Bilateral cleft epiphyses of the proximal phalanges of the first toes. C, D, The appearance in the oblique projection could be mistaken for a comminuted fracture.

A

B

FIGURE 7-634  A, Single ossification centers at the base of the first toe in an 11-year-old boy. B, One year later, the epiphysis has developed a cleft. This is a normal phenomenon that may be seen in any epiphysis. (Ref: Harrison RB, Keats TE: Epiphyseal clefts. Skeletal Radiol 5:23, 1980.)

748

The Lower Extremity  |  THE FOOT

FIGURE 7-635  Cleft epiphysis of the base of the proximal phalanx of the second toe.

A

B FIGURE 7-636  Development of cleft epiphysis. A, Age 3 years. B, Age 13 years.

The Lower Extremity  |  THE FOOT

749

PART 1  |  CHAPTER 7



FIGURE 7-637  Bilateral persistence of the type of cleft epiphysis illustrated in Figure 7-636.

FIGURE 7-638  Fossa in the base of the proximal phalanx of the first toe, possibly related to residua of cleft epiphysis.

750

The Lower Extremity  |  THE FOOT

FIGURE 7-639  Unusually deep fossa bilaterally at the base of the proximal phalanx of the first toe.

FIGURE 7-640  Deep fossa at the base of proximal phalanx. Note extension of the head of the metatarsal into the fossa.

FIGURE 7-641  Normally dense epiphysis at the base of the proximal phalanx of the first toe in a 12-year-old boy. This should not be mistaken for evidence of osteonecrosis.

The Lower Extremity  |  THE FOOT

751

PART 1  |  CHAPTER 7



FIGURE 7-642  Unusual configuration of the base of the distal phalanx of the first toe.

FIGURE 7-643  Cone epiphyses are very common in the proximal phalanges of children and are not necessarily associated with pathology.

FIGURE 7-644  Unusually large cone epiphysis in an 11-year-old boy.

A

B

FIGURE 7-645  A, Simulated fracture of the epiphysis of the first toe in the oblique projection. B, No fracture is seen in the frontal plane.

752

The Lower Extremity  |  THE FOOT

FIGURE 7-646  Left, Simulated fractures of the bases of the proximal phalanges in the oblique projection in an 11-year-old girl. Right, Frontal projection shows no fractures. Note deep fossa in the head of the third metatarsal (m 66).

A

B

FIGURE 7-647  Incomplete developmental fissures through the proximal phalanx of the first toe. A, A 10-year-old boy. B, A 12-year-old boy.

FIGURE 7-648  Incomplete developmental fissure in the middle phalanx of the second toe in an 8-year-old boy.

The Lower Extremity  |  THE FOOT

753

PART 1  |  CHAPTER 7



FIGURE 7-649  Two examples of marked irregularity in development of the phalanges in 12-year-old girls. This is a normal and transient phenomenon.

FIGURE 7-650  Developmental irregularity of the middle phalanx of the fourth toe in an 11-year-old girl, which was interpreted as a fracture.

FIGURE 7-651  Duplication of the middle phalanx of the fifth toe in a child.

FIGURE 7-652  A, Failure of fusion of a portion of the epiphysis at the base of the distal phalanx of the first toe, originally interpreted as a fracture despite absence of pertinent history or physical findings. B, Follow-up film taken 3 years later shows no change.

A

B

754

The Lower Extremity  |  THE FOOT

FIGURE 7-653  Accessory bone at the base of the distal phalanx of the first toe (see Fig. 7-652).

FIGURE 7-654  Three examples of ringlike defects seen near the joints of the toes. These represent small areas of fat necrosis but are apparently of no importance clinically. (Ref: Keats TE, et al: Idiopathic punctate necrosis of the phalanges of the feet. Skeletal Radiol 18:25, 1989.)

FIGURE 7-655  Two examples of spurlike enlargements of the distal phalanx of the great toe. They are of no clinical significance. Right, Note the ossifications between the spurs that are located in the medial supporting ligament. (Ref: Lee M, et al: Bone excrescence at the medial base of the distal phalanx of the first toe: Normal variant, reactive change, or neoplasia? Skeletal Radiol 21:161, 1992.)

The Lower Extremity  |  THE FOOT

755

PART 1  |  CHAPTER 7



FIGURE 7-656  The same entity as in Figure 7-655, seen here with osseous excrescences on both sides of the distal phalanx.

FIGURE 7-657  The same entity as in Figure 7-656, seen here in all of the toes. (Courtesy Dr. Lee Roges.)

FIGURE 7-658  Normal irregularities seen along the shafts of the proximal phalanges, not to be confused with periostitis.

FIGURE 7-659  Normal irregularity on the lateral aspect of the shaft of the proximal phalanx of the fifth toe. This change was present on the opposite side as well.

FIGURE 7-660  Simulated fractures of the proximal phalanges of the third and fourth toes.

756

The Lower Extremity  |  THE FOOT

FIGURE 7-661  Nutrient foramina of the proximal phalanges.

FIGURE 7-662  Two examples of fifth toes with only two phalanges. This is a common anatomic variant and not the product of disease. (Ref: Ellis R, et al: The two-phalanged fifth toe. JAMA 206:2526, 1968.)

FIGURE 7-663  Marked excrescences of the distal phalanx of the first toe.

The Lower Extremity  |  THE FOOT

757

PART 1  |  CHAPTER 7



FIGURE 7-664  Two-phalanged toes, an anatomic variation.

FIGURE 7-665  Pointed distal phalanges in a healthy 6-year-old girl.

FIGURE 7-666  Pointed distal phalanges in a healthy 11-year-old boy. Absence of the distal tufts may be normal and unassociated with disease.

758

The Lower Extremity  |  THE FOOT

FIGURE 7-667  A, B, Pseudocysts of the proximal phalanges of the first toes in a woman with osteoporosis.

A

B

FIGURE 7-668  Three examples of phalangeal sclerosis, a finding of no clinical significance. Top left, Proximal phalanx. Top right and bottom, Distal phalanges. (Ref: Carter BC, et al: Skeletal manifestations of idiopathic bone sclerosis. Australas Radiol 32:242, 1988.)

The Lower Extremity  |  THE FOOT

759

PART 1  |  CHAPTER 7



FIGURE 7-669  Duplication anomaly of the first toe having an articulation with the second toe.

FIGURE 7-671  Duplication of the fifth toe. FIGURE 7-670  Subungual calcification in the normal nail bed of the toe. This phenomenon, seen in adults in middle age and later life, is of no clinical significance. (From Fischer E: Subunguale Verkalkungen im normalen Nagelbett der Zehen. Radiologie 24:31, 1984.)

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CHAPTER

7

The Lower Extremity

FIGURES

THE THIGH The Femoral Head and Hip Joint The Femoral Neck The Trochanters The Shaft of the Femur The Distal End of the Femur

7S-1 to 7S-47 7S-1 to 7S-8 7S-9 to 7S-14 7S-15 to 7S-18 7S-19 to 7S-24 7S-25 to 7S-47

THE PATELLA

7S-48 to 7S-56

THE LEG The Proximal Ends of the Tibia and Fibula The Shafts of the Tibia and Fibula The Distal Ends of the Tibia and Fibula

7S-57 7S-57 7S-64 7S-67

THE FOOT The Tarsals The Accessory Ossicles The Talus The Calcaneus The Tarsal Navicular The Cuneiforms The Cuboid The Metatarsals The Sesamoid Bones The Toes

7S-89 to 7S-149 7S-89 to 7S-130 7S-89 to 7S-99 7S-100 to 7S-107 7S-108 to 7S-115 7S-116 to 7S-126 7S-127 to 7S-129 7S-130 7S-131 to 7S-145 7S-146 7S-147 to 7S-149

to to to to

7S-88 7S-63 7S-66 7S-88

7S-191

7S-192 The Lower Extremity  |  THE THIGH

THE THIGH The Femoral Head and Hip Joint

FIGURE 7S-1  Apparent radiolucency of the femoral head in a 5-year-old boy (m) produced by superimposition of the normal irregularities of the acetabulum at this age (m 6).

A

B FIGURE 7S-2  A, Unusually large bilateral fovea capitis, which may be mistaken for osteochondritis dissecans. B, Tomogram of right hip.

FIGURE 7S-3  Large fovea capitis in a 26-year-old man.



The Lower Extremity  |  THE THIGH 7S-193

A

B

FIGURE 7S-4  Simulated fracture or aseptic necrosis of the femoral head produced by the fovea capitis on plain film (A). B, No fracture is shown on the tomogram.

FIGURE 7S-6  Variation in the configuration of the femoral heads in a 5-year-old child.

FIGURE 7S-5  The shadow of the posterior acetabular margin superimposed on the femoral head may simulate the density of vascular necrosis.

FIGURE 7S-7  Unusual morphology of the femoral heads in a 26-year-old man, probably related to the fovea capitis.

7S-194 The Lower Extremity  |  THE THIGH

B

A FIGURE 7S-8  Degenerative spurring of the femoral neck that was mistaken for a subcapital fracture. A, Plain film. B, CT scan.

The Femoral Neck

FIGURE 7S-9  Simulated erosion of the right femoral neck in a 50-year-old man.



The Lower Extremity  |  THE THIGH 7S-195

A

B

C FIGURE 7S-10  A through C, Normal irregularities of the femoral necks, seen only in frog-leg projection (B, C).

A

B

FIGURE 7S-11  Asymmetric radiolucency of the right femoral neck (A) compared with the left (B), probably caused by asymmetry of position. Findings on MR imaging were normal.

7S-196 The Lower Extremity  |  THE THIGH

FIGURE 7S-12  Examples of ringlike radiolucencies of the femoral necks with sclerotic borders. These common lesions are apparently of no clinical significance. There is evidence to suggest that they represent a subcortical pit formed by herniation of synovium through the cortical bone. (Ref: Pitt MJ, et al: Herniation pit of the femoral neck. AJR Am J Roentgenol 38:1115, 1982.) Rarely, these herniation pits may grow rapidly and suggest an aggressive lesion. In some cases, the pits may enlarge, and the overlying cortex may fracture and become symptomatic. (Ref: Daenen B, et al: Symptomatic herniation pits of the femoral neck: Anatomic and clinical studies. AJR Am J Roentgenol 168:149, 1997.)

B

A

C FIGURE 7S-13  A, B, Bilateral herniation pits in a 25-year-old man. C, Demonstration of pits on CT scan.



The Lower Extremity  |  THE THIGH 7S-197

FIGURE 7S-14  Simulated periostitis of the femoral neck produced by the overlapping shadow of the greater trochanter.

The Trochanters

FIGURE 7S-15  Normal irregularities of ossification of the greater trochanter in a 12-year-old boy.

FIGURE 7S-16  Ossification variant of the greater trochanter simulating a fracture in a 15-year-old boy.

7S-198 The Lower Extremity  |  THE THIGH

FIGURE 7S-17  Simulated cyst of the femoral neck produced in abduction by the shadow of the greater trochanter.

FIGURE 7S-18  “Tug” lesion below lesser trochanter, an enthesopathy.

The Shaft of the Femur

FIGURE 7S-19  The shadow of the fascia lata, which may simulate new bone formation.



The Lower Extremity  |  THE THIGH 7S-199

B

A FIGURE 7S-20  A, The shadow of the tensor fascia lata and iliotibial band on plain film. B, T2-weighted MR image.

FIGURE 7S-21  Muscle interleaved with fat may resemble a soft tissue mass, most commonly seen in women.

7S-200 The Lower Extremity  |  THE THIGH

B A FIGURE 7S-22  Striking delineation of the muscles about the proximal femur in a young boy (A) and a 25-year-old athlete (B).

FIGURE 7S-24  Linear intramedullary densities in a 70-year-old woman. These are seen more frequently in elderly women without known disease and are apparently of no clinical significance. FIGURE 7S-23  Soft tissue companion shadow of the femur.



The Lower Extremity  |  THE THIGH 7S-201

The Distal End of the Femur

FIGURE 7S-25  Small “tug” lesion in an 11-year-old girl.

FIGURE 7S-26  Bilateral “tug” lesions of the femur, probably secondary to a pull of the vastus lateralis and vastus medialis muscles.

FIGURE 7S-27  Simulated lesions of the femur produced by the edge of the growth plates in tunnel views in a 10-year-old boy.

7S-202 The Lower Extremity  |  THE THIGH

FIGURE 7S-28  Unusual variation of the medial distal femoral irregularity in a 10-year-old boy.

FIGURE 7S-29  Well-defined posterior femoral defect in a 12-year-old girl.



The Lower Extremity  |  THE THIGH 7S-203

B

A FIGURE 7S-30  A, B, Residual posterior distal femoral defects in an 18-year-old girl, which can be seen in the frontal projection (B) as radiolucencies that might be mistaken for evidence of disease.

FIGURE 7S-31  Residuum of posterior femoral defect in a 46-year-old man, with a thin rim of bone.

7S-204 The Lower Extremity  |  THE THIGH

FIGURE 7S-33  Simulated cysts of the lateral femoral condyles, more exaggerated on the left.

A

FIGURE 7S-34  Normal irregular contours of the distal femoral epiphyses in a 4-year-old girl.

B FIGURE 7S-32  A, Apparent lucent lesion in the medial femoral condyle. B, Repositioned film shows no abnormality, the change being caused by alteration in beam direction.



The Lower Extremity  |  THE THIGH 7S-205

FIGURE 7S-35  Normal developmental irregularities of the condyles in a 12-year-old boy, which should not be mistaken for osteochondritis. (Ref: Silverman FN, Kuhn J: Caffey’s Pediatric X-Ray Diagnosis, 9th ed. St. Louis, Mosby, 1993.)

7S-206 The Lower Extremity  |  THE THIGH

FIGURE 7S-36  Simulated osteochondritis dissecans in an 11-year-old boy. Note that the irregularities are not seen in the frontal projection (top left), are well demonstrated in the tunnel projection (top center), and are seen posteriorly in the lateral projection (top right). Gradient echo, T2*-weighted MR images show normal appearance of the articular cartilage and subchondrial bone (bottom left and right).

A

B

FIGURE 7S-37  Simulated osteochondritis dissecans in a 10-year-old boy. A, Plain film. B, T2-weighted MR image.



The Lower Extremity  |  THE THIGH 7S-207

FIGURE 7S-38  Apparent ossification variant of the medial femoral condyle in a 13-year-old boy. A, AP projection shows faint radiolucency. B, Lateral projection shows no abnormality. C, Coronal gradient echo, T2*-weighted MR image shows signal alteration in area of interest. D, Sagittal gradient echo T2*-weighted image shows a subchondral defect, but was not related to the patient’s symptoms. (Ref: Nawata K, et al: Anomalies of ossification in the posterior lateral femoral condyle: Assessment by MRI. Pediatr Radiol 29:781, 1999.)

A

B

C

D

FIGURE 7S-39  Accessory ossification center of the distal femoral epiphysis, seen in lateral projection.

7S-208 The Lower Extremity  |  THE THIGH

A

B FIGURE 7S-40  A, B, Bilateral similar excrescences on the articular surfaces of the lateral condyles simulating intraarticular osteophytes.

A

B

FIGURE 7S-41  A, Simulated lesion of the anterior surface of the femoral condyle produced by rotation. B, Normal appearance on repeat examination.



The Lower Extremity  |  THE THIGH 7S-209

FIGURE 7S-42  Bilateral cyamellae in shallow popliteus grooves.

FIGURE 7S-43  Huge cyamella.

FIGURE 7S-44  Lateral meniscal ossicle.

FIGURE 7S-45  The meniscal ossicle in the posterior horn of the medial meniscus.

7S-210 The Lower Extremity  |  THE THIGH

FIGURE 7S-46  Ossicle in Hoffa’s fat pad.

FIGURE 7S-47  Some normal individuals show true asymmetry in the height of the medial and lateral compartments. Top left, A 48-year-old man. Standing films show asymptomatic symmetric narrowing of the medial compartments. Top right, Films of the same person 10 years later show no change in compartment height. Gradient echo, T2*-weighted coronal and sagittal MR images obtained at this time (bottom) show normal articular cartilage. These variations are probably related to known normal differences in thickness of articular cartilage in normal persons. (Refs: Hall FM, Wyshak G: Thickness of articular cartilage in the normal knee. J Bone Joint Surg Am 62:408, 1980; Brandt KD, et al: Radiographic grading of the severity of knee osteoarthritis. Arthritis Rheum 34:1381, 1991.)

THE PATELLA

FIGURE 7S-48  Unusual patterns of ossification of the patella in a 6-year-old boy.

FIGURE 7S-49  Left, Accessory ossification center in an 8-year-old boy diagnosed as a fracture. Right, Film made 1 month later, after no treatment, shows progressive closure of the secondary center.

FIGURE 7S-50  Variation in development of the patella in an 11-year-old child with cerebral palsy, possibly the result of traction by the quadriceps and the patellar tendons. These centers often close, leaving an elongated patella.

7S-212 The Lower Extremity  |  THE PATELLA

FIGURE 7S-51  Accessory patellar ossification center, seen in tangential projection in a 2-year-old boy.

FIGURE 7S-52  Segmented patella showing poor definition of septa in the oblique projection (right).

FIGURE 7S-53  Bilateral dorsal patellar defects in a 13-year-old girl.



The Lower Extremity  |  THE PATELLA 7S-213

FIGURE 7S-54  Dorsal defects in an elderly man. These defects are seen more commonly in young people but occasionally persist into later life. Top left, Frontal view. Top right, Lateral view. Bottom, Tangential views.

FIGURE 7S-55  Simulated fracture of the upper pole of the patella, produced by a small flangelike projection.

7S-214 The Lower Extremity  |  THE LEG

FIGURE 7S-56  Unusual caudal extensions of the patella in an adult.

THE LEG The Proximal Ends of the Tibia and Fibula

FIGURE 7S-57  An ossicle at the fourth tubercle on the dorsal aspect of the proximal tibial surface. Note the marked concavity of the posterior aspect of the patella. (Ref: Kohler A, Zimmer EA: Borderlands of the Normal and Early Pathologic Findings in Skeletal Roentgenology, 3rd ed. New York, Grune & Stratton, 1968.)



The Lower Extremity  |  THE LEG 7S-215

FIGURE 7S-58  Three examples of normal variation in appearance of the ossification center of the tibial tubercle in adolescence.

FIGURE 7S-59  The edge of the proximal tibial epiphysis as seen in lateral projection may simulate a fracture.

7S-216 The Lower Extremity  |  THE LEG

B

A

D C

FIGURE 7S-60  An appearance similar to the lesions in Figure 7-241 may be produced by ganglion cysts. A, B, Plain films. C, T1-weighted sagittal MR image. D, Gradient echo T2-weighted sagittal MR image. E, Gradient echo T2-weighted coronal MR image.

E



The Lower Extremity  |  THE LEG 7S-217

FIGURE 7S-61  Small spur at the medial tibial metaphysis, probably representing a “tug” lesion.

FIGURE 7S-62  Developmental bulge of the medial tibial metaphysis.

FIGURE 7S-63  Ossicle at head of the fibula simulating a fracture.

7S-218 The Lower Extremity  |  THE LEG

The Shafts of the Tibia and Fibula

A

B

C

FIGURE 7S-64  Transverse (growth arrest) line of the tibia. A, Frontal projection. B, Lateral projection. C, T1-weighted sagittal MR image.

FIGURE 7S-65  Localized ossification in the interosseous membrane.



The Lower Extremity  |  THE LEG 7S-219

FIGURE 7S-66  Three examples of nutrient foramina of the fibula that might be mistaken for fractures. (Ref: Lee J-H, et al: Nutrient canal of the fibula. Skeletal Radiol 29:22, 2000.)

The Distal Ends of the Tibia and Fibula

FIGURE 7S-68  Normal radiolucencies in the distal fibular epiphyses.

FIGURE 7S-67  Tibial flange that might be mistaken for an avulsion fracture.

FIGURE 7S-69  Calcification of the syndesmotic membrane (m). There is also an accessory bone at the lateral aspect of the distal fibula (m 6).

7S-220 The Lower Extremity  |  THE LEG

FIGURE 7S-70  Another example of the accessory bone seen in Figure 7S-69.

FIGURE 7S-71  Closing epiphyseal line in a 13-year-old boy, which was misinterpreted as a fracture.

FIGURE 7S-72  Residua of the epiphyseal line of the fibula in an 18-yearold, not to be mistaken for fracture.

FIGURE 7S-73  Residua of the epiphyseal line of the fibula in a 19-year-old.



The Lower Extremity  |  THE LEG 7S-221

FIGURE 7S-74  Fibular ossicle on the medial side in a 13-year-old boy.

FIGURE 7S-75  Simulated fractures of the posterior malleolus produced by the Mach effect of overlap of the tibia and fibula.

7S-222 The Lower Extremity  |  THE LEG

A

B

FIGURE 7S-76  A, Medial malleolar ossicle simulating a fracture in frontal projection. B, Oblique projection shows cortication of the ossicle.

FIGURE 7S-77  Closing accessory ossification center for the medial malleolus in an 8-year-old boy.

FIGURE 7S-78  Developmental lucency in the medial malleolus in a 10-year-old boy.



The Lower Extremity  |  THE LEG 7S-223

B

A

FIGURE 7S-79  Bifid medial malleolus, representing the anterior and posterior colliculi. A, Frontal projection. B, Oblique projection.

B A FIGURE 7S-80  A, Simulated fracture of the medial malleolus secondary to rotation produced by poor positioning. B, Correct AP projection shows no fracture.

FIGURE 7S-81  Small fossa on the articular surface of the posterior malleolus is of no clinical significance.

7S-224 The Lower Extremity  |  THE LEG

FIGURE 7S-82  Normal undulations of the cortex of the posterior malleolus.

FIGURE 7S-83  An example of the os subfibulare. Multiple irregular fragments have persisted into adult life in a 19-year-old man.

FIGURE 7S-84  Incomplete fusion of the ossification center for the lateral malleolus in an adult simulating a fracture.



The Lower Extremity  |  THE LEG 7S-225

FIGURE 7S-85  The shadow of the Achilles tendon in the oblique projection.

FIGURE 7S-86  Spurlike extension of the distal end of the lateral malleolus.

FIGURE 7S-87  Another example of the entity illustrated in Figure 7S-86.

7S-226 The Lower Extremity  |  THE LEG

A

C

B

D

FIGURE 7S-88  The accessory soleus muscle. A, No abnormality of posterior soft tissues of the right ankle. B, Soft tissue mass in posterior soft tissues of left ankle. C, CT scans of each calf show a mass with the density of muscle in the left calf (m). The right calf is normal. D, CT scans of both ankles show a well-defined mass between the tibia and the Achilles tendon on the left (m). (Ref: Apple JS, et al: Case report 376. Skeletal Radiol 15:398, 1986; Yu JS, Resnick D: MR imaging of the accessory soleus muscle appearance in 6 patients and a review of the literature. Skeletal Radiol 23:525, 1994.)



The Lower Extremity  |  THE FOOT 7S-227

THE FOOT The Tarsals THE ACCESSORY OSSICLES

FIGURE 7S-89  The os supratalare.

A

B

FIGURE 7S-90  A, The os trigonum may closely simulate a fracture of the posterior process of the talus. B, The problem may require tomography for resolution.

7S-228 The Lower Extremity  |  THE FOOT

FIGURE 7S-91  The os talotibiale. FIGURE 7S-92  A multicentric os talotibiale.

FIGURE 7S-93  A small os peroneum.

FIGURE 7S-94  Huge os tibiale externum.



The Lower Extremity  |  THE FOOT 7S-229

FIGURE 7S-96  The os peroneum in frontal projection.

FIGURE 7S-95  Bipartite os tibiale externum.

FIGURE 7S-97  Unusual os peroneum.

7S-230 The Lower Extremity  |  THE FOOT

FIGURE 7S-98  Accessory ossicle adjacent to the cuboid.

FIGURE 7S-99  The os intermetatarseum with incomplete ring.

THE TALUS

FIGURE 7S-101  Unusual posterior process of the talus and os trigonum having articulation with the calcaneus.

FIGURE 7S-100  An unusual os trigonum that articulates with the posterior process of the talus.



The Lower Extremity  |  THE FOOT 7S-231

FIGURE 7S-103  Prominent trabecular pattern simulating fracture of the talus. FIGURE 7S-102  Talar beak with two large articulating ossicles.

FIGURE 7S-104  The talus accessorius.

A

B

FIGURE 7S-105  Large os tibiale externa may be confused with os sustentaculi, which are lower in position. A, B, Axial projections of the calcaneus.

7S-232 The Lower Extremity  |  THE FOOT

FIGURE 7S-106  Talus partitus, an unusual developmental anomaly in which the talus is partitioned, seen in a tomogram of the right ankle. (Ref: Schreiber A et al: Talus partitus: A case report. J Bone Joint Surg Br 67:430, 1985.) (Courtesy of Dr. L.W. Bassett.)

FIGURE 7S-107  Partial coalition between the talus and navicular, seen on oblique projection.



The Lower Extremity  |  THE FOOT 7S-233

THE CALCANEUS

FIGURE 7S-108  Proximal end of the closing calcaneal apophysis, which should not be mistaken for fracture.

A

B FIGURE 7S-109  Closing calcaneal apophysis in a 13-year-old boy. A, Lateral projection. B, Oblique projection.

FIGURE 7S-110  Incomplete closure of the distal portion of the calcaneal apophysis in a 15-year-old boy.

7S-234 The Lower Extremity  |  THE FOOT

FIGURE 7S-111  Developmental fossae in the calcaneal tuberosity, seen in oblique projection.

FIGURE 7S-112  Simulated fracture of the talus in lateral projection, produced by overlapping shadow of the distal fibular epiphysis in an 8-year-old girl.

FIGURE 7S-113  Probable vascular lucency in anterior portion of the calcaneus.



The Lower Extremity  |  THE FOOT 7S-235

A

B

FIGURE 7S-114  A, B, Normal contour alterations seen in the axial projection of the calcanei, which should not be mistaken for fractures.

FIGURE 7S-115  Medial calcaneal cleft on MR image.

7S-236 The Lower Extremity  |  THE FOOT

THE TARSAL NAVICULAR

FIGURE 7S-116  Simulated cyst of the navicular produced by configuration of upper cortical margin.

FIGURE 7S-117  Normal ossification of the navicular from multiple centers in an 8-year-old boy. This appearance may be confused with osteochondritis or a fracture.



The Lower Extremity  |  THE FOOT 7S-237

FIGURE 7S-118  Bilateral bipartite tarsal naviculars in an adult. Note the unusual configuration of the bone in the frontal projection. (Ref: Kohler A, Zimmer EA: Borderlands of Normal and Early Pathological in Skeletal Radiography, 4th ed. New York, Thieme, 1993; Shawdon A, et al: The bipartite tarsal navicular bone: Radiographic and computed tomography findings. Australas Radiol 39:192, 1995.)

FIGURE 7S-119  Abortive bipartite navicular.

7S-238 The Lower Extremity  |  THE FOOT

B

A

C FIGURE 7S-120  Abortive bipartite navicular. Note the unusual appearance in the A, AP, B, lateral, and C, oblique projections.

FIGURE 7S-121  Bilateral partial fusion of the os tibiale externum to the navicular. The arrows point to the remnants of the line of fusion.



The Lower Extremity  |  THE FOOT 7S-239

FIGURE 7S-122  The os tibiale externum in frontal (left) and lateral (right) projections.

FIGURE 7S-123  Os tibiale externum in lateral projection simulating a fracture of the cuboid.

A

B FIGURE 7S-124  A, B, Bilateral incorporated os supranaviculare.

7S-240 The Lower Extremity  |  THE FOOT

FIGURE 7S-125  Top, Large navicular with spurlike extension posteriorly (m). Bottom, Similar appearance is seen on the opposite side.

FIGURE 7S-126  Contour alteration of the anterior aspect of the navicular which may be mistaken for a fracture.



The Lower Extremity  |  THE FOOT 7S-241

THE CUNEIFORMS

A

C

B

D

FIGURE 7S-127  A through D, Confusing appearance at base of first metatarsal, simulating a fracture in a 15-year-old boy, is produced by overlapping shadows of the first cuneiform and the epiphysis of the base of the first metatarsal. The epiphyseal line at the base of the metatarsal is seen in C and is demonstrated by tomography in D.

7S-242 The Lower Extremity  |  THE FOOT

FIGURE 7S-129  Simulated fracture produced by a well-demonstrated joint between the fourth metatarsal and the third cuneiform.

FIGURE 7S-128  The overlapping relationships illustrated in Figure 7S-127 are better defined in the adult.

THE CUBOID

A

B

FIGURE 7S-130  A, Simulated fracture of the cuboid. B, Magnification view shows that the simulated fracture is caused by the dense cortex of the upper margin of the bone.



The Lower Extremity  |  THE FOOT 7S-243

The Metatarsals

FIGURE 7S-131  Oblique fissures in the metaphysis of the distal end of the first metatarsal, not to be mistaken for fractures.

FIGURE 7S-132  Normal irregularities of the bases of the metatarsals in a 3-year-old boy.

7S-244 The Lower Extremity  |  THE FOOT

FIGURE 7S-133  Asymmetric closure of the apophysis of the base of the fifth metatarsal in an 11-year-old boy. Top, Left foot. Bottom, Right foot.

FIGURE 7S-134  Very large apophyses at the bases of the fifth metatarsals in an 11-year-old boy.



The Lower Extremity  |  THE FOOT 7S-245

FIGURE 7S-135  Bilateral closing apophyses of the type shown in Figure 7S-134, here in a 12-year-old boy, which could be mistaken for fractures. Left and center, Left foot. Right, Right foot.

FIGURE 7S-136  Unfused apophysis at the base of the fifth metatarsal in a 19-year-old man. Note that the apophysis is located at the end of the metatarsal rather than in its usual lateral position. This is an unusual but not rare variation in the position of the apophysis.

7S-246 The Lower Extremity  |  THE FOOT

C

B A

D

E

FIGURE 7S-137  A through C, Transverse apophysis of the base of the fifth metatarsal in an 11-year-old girl. D, E, Two-year follow-up at age 13 years.



The Lower Extremity  |  THE FOOT 7S-247

A

B

FIGURE 7S-138  A, Cystlike radiolucency in the base of the fifth metatarsal in a 14-year-old girl. B, Follow-up film taken 5 months later shows normal appearance.

FIGURE 7S-140  Accessory ossicle at the base of the third metatarsal.

FIGURE 7S-139  Notch of the base of the fifth metatarsal that might be mistaken for evidence of fracture.

7S-248 The Lower Extremity  |  THE FOOT

FIGURE 7S-142  Developmental cleft at the base of the fourth metatarsal in a young child. FIGURE 7S-141  Simulated fracture of the base of the fourth metatarsal, resulting from overlapping of the cuboid.

FIGURE 7S-143  Os intermetatarseum arising from the base of the first metatarsal.



The Lower Extremity  |  THE FOOT 7S-249

FIGURE 7S-144  Simulated fracture of the first metatarsal produced by the os intermetatarseum.

FIGURE 7S-145  Partial closure of the physes of the fourth and fifth metatarsals in a 14-year-old girl.

The Sesamoid Bones

FIGURE 7S-146  Prominent facet for the medial sesamoid at the first metatarsal.

7S-250 The Lower Extremity  |  THE FOOT

The Toes

FIGURE 7S-148  Fissures in the first, second, and third toes of a 10-yearold boy. FIGURE 7S-147  Fossa at the lateral aspect of the base of the proximal phalanx of the first toe, with small ossicle within.

FIGURE 7S-149  Normal irregularities seen along the shafts of the proximal phalanges, not to be confused with periostitis.

PART

TWO The Soft Tissues

761

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CHAPTER

8

The Soft Tissues of the Neck PAGES 763 to 791

FIGURES THE SOFT TISSUES OF THE NECK

8-1 to 8-79

THE SOFT TISSUES OF THE NECK

FIGURE 8-1  Shadows of the lips seen in frontal projection of the mandible. (Ref: Bohrer SP, Brody JA: More than just lip service. Skeletal Radiol 21:305, 1992.)

763

764

The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

FIGURE 8-2  Pseudotumor of the nasal passage produced by superimposition of the coronoid process of the mandible on the inferior turbinate. (Ref: Sistrom CL, Keats TE, Johnson CM: The anatomic basis of the pseudotumor of the nasal cavity. AJR Am J Roentgenol 147:782, 1986.)

A

FIGURE 8-3  Normal configuration of the soft tissues of the mouth and oropharynx in a 1-year-old infant during swallowing, showing tongue (m), soft palate (m 6 ), and adenoids (m 66).

B

C FIGURE 8-4  A, Summation shadow of the occiput and upper lip. B, Tongue in frontal projection. C, Tongue in lateral projection. (Courtesy Dr. Stan Bohrer.)



The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

A

765

B

FIGURE 8-5  A, Pseudomass of the pharynx produced by the base of the tongue, filmed during the act of swallowing. B, Normal configuration of soft tissues at rest in another patient for contrast with A.

FIGURE 8-6  Simulated submandibular mass produced by redundancy of soft tissues of the neck.

FIGURE 8-7  Normal irregularity of the surface of the base of the tongue caused by lymphoid tissue.

766

The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

FIGURE 8-8  Base of the tongue seen in the basal view of the skull. FIGURE 8-9  Large but normal adenoids in a young adult. The lucency within is caused by superimposition of the nasopharyngeal air shadow.

FIGURE 8-10  Calcification in the adenoids.

FIGURE 8-12  Prominent soft palate and uvula.

FIGURE 8-11  Air between the hard palate and the tongue.

FIGURE 8-13  Large soft palate (m) and uvula (m 6).



The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

FIGURE 8-15  Pharyngeal tonsil in a 3-year-old boy. FIGURE 8-14  Shadow of the uvula seen in the basal view of the skull.

FIGURE 8-16  Two examples of large pharyngeal tonsils, which may simulate a tumor of the pharynx.

767

768

The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

FIGURE 8-17  Two examples of calcification in the tonsillar crypts. (Ref: Aspestrand F, Kolbenstvedt A: Calcifications of the palatine tonsillary region: CT demonstration. Radiology 165:479, 1987.)

FIGURE 8-18  Parotid or tonsillar stone.

FIGURE 8-19  Shadow of the ear lobe simulating a mass in the nasopharynx.



The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

FIGURE 8-20  Ear lobe simulating mass lesions, seen in preliminary films for submaxillary sialography.

A

B

FIGURE 8-21  A, Simulated soft tissue mass produced by the soft palate during phonation. B, Same patient at rest. No mass present.

769

770

The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

FIGURE 8-23  Elongated epiglottis. FIGURE 8-22  Bulbous distal end of epiglottis is a normal variation, not to be mistaken for the swelling of epiglottis. Note the normal aryepiglottic folds. The patient had croup.

A

B

C

FIGURE 8-24  Normal alterations of the retropharyngeal soft tissues with respiration in infancy. A, Quiet breathing. B, Expiration. C, Inspiration. The expiratory film resembles the changes of retropharyngeal abscess and is a potential source of misinterpretation.



The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

A

771

B

FIGURE 8-25  A, B, Expiratory prominence of the retropharyngeal soft tissues in infants. Note the small air collection in the soft tissues of the patient illustrated in B. Both the prominence of the soft tissues and the air disappear on inspiration. (Ref: Currarino G, Williams B: Air collections in the retropharyngeal soft tissues observed in lateral expiratory films of the neck in 9 infants. Pediatr Radiol 23:186, 1993.)

A

B

FIGURE 8-26  Air in the pyriform sinuses in a 1-year-old infant, which explains the appearance seen in Figure 8-25B. A, Lateral projection. B, Axial CT scan.

772

The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

FIGURE 8-27  Retropharyngeal soft tissue changes with respiration in a 1-year-old. Left, Expiration. Right, Inspiration.

A

B

FIGURE 8-28  Residual normal prominence of retropharyngeal soft tissues in a 10-year-old. A, Inspiration. B, Expiration. Note similarity to the changes of retropharyngeal abscess.



The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

773

B

A FIGURE 8-29  A, Normal prominence of the prevertebral soft tissues simulating the changes of trauma on expiration. B, Same patient on inspiration.

FIGURE 8-30  Prominence of the soft tissues at C2. CT scan was normal.

FIGURE 8-31  Marked prominence of the prevertebral soft tissues on expiration.

774

The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

FIGURE 8-32  Thickening of the retropharyngeal tissues may be seen to a lesser degree in adults. Left, Inspiration. Right, Expiration. Transposition of the carotid arteries anterior from their normal lateral positions into the retropharyngeal soft tissues, resulting in striking thickening of the retropharyngeal soft tissues at C2 and C3, has been described in elderly patients. (Ref: Fix TJ, et al: Carotid transpositions: Another cause of wide retropharyngeal soft tissues. AJR AM J Roentgenol 167:1305, 1996.)

FIGURE 8-33  Localized anterior bulging of soft tissues and impression on the posterior aspect of the trachea in an adult in expiration.

FIGURE 8-34  Prominent prevertebral fat stripe, not to be mistaken for gas in the soft tissues. (Ref: Whalen JP, Woodruff CL: The cervical prevertebral fat stripe: A new aid in evaluating the cervical prevertebral soft tissue space. Am J Roentgenol Radium Ther Nucl Med 109:445, 1970.)



The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

775

FIGURE 8-35  Styloid processes, which should not be mistaken for foreign bodies.

FIGURE 8-36  Stylohyoid ligament calcification in an 11-year-old girl.

A

B FIGURE 8-37  Calcified stylohyoid ligaments in lateral (A) and oblique (B) projections.

776

The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

A

B

FIGURE 8-38  Extensively calcified stylohyoid ligaments in frontal (A) and lateral (B) projections (m). Note the articulation at the junction of the ligament and the styloid process (m 66). (Ref: Genez BM, et al: Case report 584: Ossified stylohyoid complex with pseudarthroses. Skeletal Radiol 18:623, 1989.)

FIGURE 8-39  Calcified stylohyoid ligaments with multiple segments.



The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

777

FIGURE 8-40  Calcified stylohyoid ligament with multiple articulations.

FIGURE 8-41  Large calcified stylohyoid ligaments.

FIGURE 8-43  Unilateral calcified stylohyoid ligament in an 11-year-old girl that was mistaken for a foreign body. FIGURE 8-42  Partial calcification of the stylohyoid ligaments simulating a foreign body.

778

The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

FIGURE 8-45  The hyoid bone in an 18-year-old woman. The synchondrosis between the body and greater cornua should not be mistaken for a fracture (m). Note also the lesser cornua (m 6 ).

FIGURE 8-44  Stylohyoid ligament calcification mistaken for an impacted chicken bone.

FIGURE 8-46  Simulated fracture of the hyoid in a 12-year-old girl.

FIGURE 8-47  Variation in anatomy of the hyoid bone. Note the inclination of the body of the hyoid compared with the preceding figure.



The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

FIGURE 8-48  Arytenoid “bump.”

A

B FIGURE 8-49  Variations in the arytenoid with phonation. A, Quiet breathing. B, Phonation.

779

780

The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

FIGURE 8-50  Calcification in the thyrohyoid ligament.

FIGURE 8-52  Calcification of the thyroid cartilages simulating carotid artery calcification.

FIGURE 8-51  Calcification in the arytenoid cartilage. (Ref: Jurik AG: Ossification and calcification of the laryngeal skeleton. Acta Radiol Diagn 25:17, 1984.)

FIGURE 8-53  Calcification of the entire thyroid cartilage.



The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

FIGURE 8-54  Calcification of the superior cornua of the thyroid cartilage, which might be mistaken for a foreign body.

781

FIGURE 8-55  Superior cornua of the thyroid cartilage as a separate ossicle. Note also the calcification of the stylohyoid ligaments.

FIGURE 8-56  Superior cornua of the thyroid cartilage as a separate ossicle with an articulation.

782

The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

FIGURE 8-57  Huge superior cornua of the thyroid cartilage. FIGURE 8-58  Calcification in the arytenoid cartilages (m). Note also a submaxillary gland calculus (m 6 ), and calcification in the posterior lamina of the cricoid cartilage (m 66).

FIGURE 8-59  Calcification of the cricoid cartilages.



The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

A

783

B

FIGURE 8-60  A, When seen in isolation, calcification of the posterior cricoid lamina may be easily confused with a foreign body. B, In a patient with more extensive calcification of the larynx, the relationship to the density seen in A is more easily identified.

A

B

FIGURE 8-61  Horizontal calcification of the superior cornua of the thyroid cartilage mistaken for a foreign body. A, Conventual image. B, CT scan.

784

The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

FIGURE 8-62  Left, Unusually long tubular calcification arising from the cricoid cartilage and descending anteriorly and inferiorly. Right, CT scan shows the same structure. The nature of this variant is unknown. (From Nidecker A, et al: The cricoid cartilage: Observations on some roentgen variants. ORL J Otorhinolaryngol Relat Spec 44:170, 1982.)

FIGURE 8-63  Physiologic calcification of the soft tissues of the neck. The upper arrow indicates calcification in the thyrohyoid ligament (cartilago triticea). The middle arrow shows calcification in the arytenoid cartilage. The lower arrow indicates calcification in the tracheal cartilage.

FIGURE 8-64  Prominent calcifications of the thyroid ligament.



The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

785

FIGURE 8-66  Calcifications in the frontal projection: thyroid cartilage (m), thyroid ligament (m 6 ), hyoid bone (m 66), and carotid arteries (m 666).

FIGURE 8-65  Calcified arytenoid (m) and calcification of tracheal cartilages (m 66) in a 37-year-old woman.

FIGURE 8-67  Marked calcification in the thyrohyoid ligament in a 28-year-old woman.

786

The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

FIGURE 8-68  Very dense calcification of the thyroid cartilages.

FIGURE 8-69  Shadow of the glottis was originally misinterpreted as a fracture of the vertebral body.

FIGURE 8-70  Air in laryngeal the ventricle was mistaken for an abscess.



The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

787

FIGURE 8-71  Variations in the appearance of the normal closed glottis in frontal projection. (Ref: Wittrum C, Kenny JB: The radiographic appearances of the larynx on the chest radiograph. Br J Radiol 67:755, 1994.)

788

The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

FIGURE 8-72  The suprasternal fossa in a newborn infant may simulate the distended proximal pouch of an esophageal atresia. (Ref: Hernandez R, et al: The suprasternal fossa on chest radiographs in newborns. AJR Am J Roentgenol 130:745, 1978.)

FIGURE 8-73  Pseudomass produced by deep pyriform sinuses.



The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

789

B

A

C FIGURE 8-74  Suprasternal fossa in older children (A) or thin adults (B, C) may be quite deep and may cast a radiolucency that can be mistaken for an air-filled esophageal diverticulum. (Ref: Ominsky S, Berinson HS: The suprasternal fossa. Radiology 122:311, 1976.)

FIGURE 8-75  Simulated gas in the soft tissues produced by the suprasternal fossa.

FIGURE 8-76  Simulated interstitial air in the posterior neck caused by hair braids.

790

The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

FIGURE 8-77  Herniation of the apex of the right lung in a 1-year-old infant.

FIGURE 8-78  Hair braids simulating a calcific thyroid mass.



The Soft Tissues of the Neck  |  THE SOFT TISSUES OF THE NECK

FIGURE 8-79  Hair braids simulating interstitial emphysema of the soft tissues of the neck.

791

CHAPTER

9

The Soft Tissues of the Thorax PAGES

FIGURES

792 to 809

THE CHEST WALL

9-1 to 9-54

810 to 823

THE PLEURA

9-55 to 9-91

824 to 845

THE LUNGS

9-92 to 9-150

846 to 871

THE MEDIASTINUM

9-151 to 9-212

871 to 901

THE HEART AND GREAT VESSELS

9-213 to 9-282

901 to 913

THE THYMUS

9-283 to 9-314

THE CHEST WALL

FIGURE 9-1  Hair braids simulating gas in the soft tissues of the neck.

FIGURE 9-2  Plastic hair braid beads producing unusual appearance of the soft tissues of the neck and shoulders.

792



The Soft Tissues of the Thorax  |  THE CHEST WALL

FIGURE 9-3  Simulated parenchymal lesions caused by hair braids (m). Note similar shadow laterally on right (m 6 ).

793

FIGURE 9-4  The dense juvenile breast may cast shadows simulating parenchymal density (m). Note also shadows cast by hair braids (m 6).

FIGURE 9-5  Juvenile breast simulating parenchymal abnormality

FIGURE 9-6  Intersecting shadows of the breast (m) and pectoral folds (m 6).

The Soft Tissues of the Thorax  |  THE CHEST WALL

794

FIGURE 9-8  Simulated pneumothorax caused by a skin fold in a 31⁄2-year-old child.

FIGURE 9-7  Skin folds producing curvilinear densities in the lower thorax and upper abdomen in a 3-week-old infant.

A

B FIGURE 9-9  Simulated pneumothorax in a neonate produced by a skin fold. A, Simulated pneumothorax. B, Normal appearance 5 hours later.

FIGURE 9-10  Two examples of simulated pneumothoraces produced by skin folds in neonates.



The Soft Tissues of the Thorax  |  THE CHEST WALL

795

FIGURE 9-11  Folds of lax skin in the elderly may also simulate a pneumothorax.

B

A

C

D

FIGURE 9-12  A through D, Four examples of skin folds simulating pneumothoraces. The patient illustrated in D was intubated. Note the fading margin of the skin fold in contrast to the sharp pleural line seen with a true pneumothorax. (Ref: Fisher JK: Skin fold versus pneumothorax. AJR Am J Roentgenol 130:791, 1978.)

796

The Soft Tissues of the Thorax  |  THE CHEST WALL

FIGURE 9-13  Examples of axillary folds simulating pneumothorax in lateral projection.

FIGURE 9-14  Redundant soft tissues of the axilla producing rounded densities overlying the mediastinum.

FIGURE 9-15  Nonsignificant asymmetry of the companion shadows of the clavicles resulting from faulty positioning. No shadow is seen on the left side.



The Soft Tissues of the Thorax  |  THE CHEST WALL

FIGURE 9-16  Calcification in the costoclavicular fascia, not to be mistaken for parenchymal lesions. A, Plain film. B, Tomogram.

A

B

FIGURE 9-17  Calcified costal cartilage may simulate a parenchymal lesion. A, Plain film. B, Tomogram.

B

A

FIGURE 9-18  Exuberant calcified costal cartilage at the end of the first rib may produce a mass effect behind the sternum in the anterior mediastinum. A, Plain film. B, Tomography in the lateral projection shows that the mass consists of the calcified cartilage (m). Note the position of trachea for orientation (m 6).

A

FIGURE 9-19  Ring shadow of calcified costal cartilage of first rib simulating a cavity in the lung.

B

797

798

The Soft Tissues of the Thorax  |  THE CHEST WALL

FIGURE 9-20  Simulated nodule produced by underdevelopment of the anterior end of the first rib, with isolated development of the costal cartilage. Left, Plain film. Right, Tomogram.

FIGURE 9-21  The floor of the supraclavicular fossa may be very well defined and may simulate an air-fluid level in the lung. (Ref: Christensen EE, Dietz GW: The supraclavicular fossa. Radiology 118:37, 1976.) FIGURE 9-22  The confluence of the shadows of the sternocleidomastoid muscle, the first rib, and the clavicle may simulate a bulla or cavity in the apex of the lung.

A FIGURE 9-23  Two examples of the shadows of the subcostal muscles that produce an appearance simulating pleural thickening or a small pneumothorax.

B



The Soft Tissues of the Thorax  |  THE CHEST WALL

FIGURE 9-24  Companion shadows of the ribs.

FIGURE 9-25  Triangular companion shadow of the first rib.

A

B

FIGURE 9-26  A, PA film shows bilateral soft tissue shadows resulting from large pectoral muscles. B, AP film does not show pectoral shadows.

799

800

The Soft Tissues of the Thorax  |  THE CHEST WALL

FIGURE 9-27  Large pectoral shadows in a weightlifter producing hazy densities in midlung, more marked on the right.

FIGURE 9-28  Congenital absence of the left pectoralis major muscle producing increased radiolucency of the left hemithorax.

FIGURE 9-29  Shadow of the pectoralis major muscle simulating a lung lesion (m). Note also the pseudopneumothorax on the patient’s right side, produced by a skin fold (6n).



The Soft Tissues of the Thorax  |  THE CHEST WALL

801

FIGURE 9-30  Extrapleural fat in a very obese man simulating pleural thickening. The absence of blunting of the costophrenic angles in this entity is a useful differential clue. (Refs: Vix VA: Extrapleural costal fat. Radiology 112:563, 1974; Sargent EN, et al: Subpleural fat pads in patients exposed to asbestos: Distinction from non-calcified pleural plaques. Radiology 152:273, 1984.)

FIGURE 9-31  Additional example of extrapleural fat deposits in a very obese patient simulating pleural thickening. The shadow of the extrapleural fat does not reach the costophrenic angles. Occasionally these extrapleural fat deposits may be slightly asymmetric. (Ref: Friedman AC, et al: Asbestosrelated pleural disease and asbestosis: A comparison of CT scan and chest radiography. AJR Am J Roentgenol 150:269, 1988.)

802

The Soft Tissues of the Thorax  |  THE CHEST WALL

FIGURE 9-32  Extrapleural fat seen in an off-lateral projection. Note that the fat loses its prominence at the bases.

FIGURE 9-33  The serratus anterior muscle produces a shadow that may be confused with pleural thickening or extrapleural fat. In frontal views, it produces a “bowling pin” configuration. (Ref: Gilmartin D: The serratus anterior muscle on chest radiographs. Radiology 131:629, 1979.)



The Soft Tissues of the Thorax  |  THE CHEST WALL

FIGURE 9-34  Two additional cases showing the varying appearance of the serratus anterior muscle shadows.

803

804

The Soft Tissues of the Thorax  |  THE CHEST WALL

A

FIGURE 9-35  A demonstration of the muscle slips of the serratus anterior muscle that constitute the “bowling pin” sign in Figures 9-33 and 9-34.

B FIGURE 9-36  A, Simulated parenchymal density produced by soft tissues over the scapula, caused by improper positioning of the arms. B, Shadow not seen with proper positioning. (Ref: Lams PM, Jolles H: The scapula companion shadow. Radiology 138:19, 1981.)

FIGURE 9-37  In an improperly positioned chest film, the spine of the scapula may overlap the lungs and produce a shadow that may be mistaken for a pneumothorax. (Ref: Harbin WP, Cimmino CV: The radiographic innominate lines of the scapular spine. Va Med Mon 101:1050, 1974.)



The Soft Tissues of the Thorax  |  THE CHEST WALL

805

FIGURE 9-38  Simulated pneumothorax produced by the transverse process of T2.

FIGURE 9-39  Confluence of the first and second ribs simulating a pneumothorax.

FIGURE 9-40  Lucency of the medullary cavity of the second rib simulating a pneumothorax.

FIGURE 9-41  Two examples of the mammary anterior mediastinal pseudotumor. The lateral aspects of the dense, small breasts in young women may project into the anterior mediastinum in the lateral projection and simulate mediastinal masses. (Ref: Keats TE: Mammary anterior mediastinal pseudotumor. J Can Assoc Radiol 27:262, 1976.)

806

The Soft Tissues of the Thorax  |  THE CHEST WALL

FIGURE 9-43  The compressed breast in the prone position may simulate a pneumothorax.

FIGURE 9-42  The axillary tail of the breast may simulate an anterior mediastinal mass.

FIGURE 9-45  Pectoral skin fold simulating pneumothorax

FIGURE 9-44  The axillary fold simulating a pneumothorax.



The Soft Tissues of the Thorax  |  THE CHEST WALL

807

FIGURE 9-46  Three examples of the sternal insertion of the pectoralis major muscle that might be mistaken for carcinoma on mammography. Top, Triangular area of increased density is seen in the medial aspect of the breast on craniocaudal view (m 6 ), continuous with underlying pectoral muscle (m). Center, Rounded area of increased density is seen in the medial aspect of the breast on craniocaudal view. Bottom, Craniocaudal view of left breast in a female weightlifter reveals continuity between pectoral muscle (m) and density (m 6). (From Britton CA, et al: Carcinoma mimicked by sternal insertion of the pectoral muscle. AJR Am J Roentgenol 153:955, 1989.)

FIGURE 9-47  Nipple shadow. Such shadows characteristically have a fading medial margin. (Ref: Ferris RA, White AF: The round nipple shadow. Radiology 121:293, 1976.)

FIGURE 9-48  Simulated herniation of the lung produced by an inflatable brassiere.

808

The Soft Tissues of the Thorax  |  THE CHEST WALL

FIGURE 9-49  Prosthetic breast implants. Note the resulting pseudotumor on the lateral projection.

FIGURE 9-50  Simulated air in soft tissues produced by rotation.



The Soft Tissues of the Thorax  |  THE CHEST WALL

809

FIGURE 9-51  Air under the breast producing a striking radiolucency beneath the heart shadow in the lateral projection.

FIGURE 9-53  Simulated consolidation of the lung produced by superimposed breast shadows.

FIGURE 9-52  Breast shadow simulating pulmonary infiltrate.

FIGURE 9-54  Manubrium simulating a soft tissue mass in a 21⁄2-year-old boy.

810

The Soft Tissues of the Thorax  |  THE PLEURA

THE PLEURA

FIGURE 9-55  Subcostal muscle simulating pleural thickening (bottom) or pneumothorax (top).

FIGURE 9-57  Shadow of the descending aorta simulating localized pneumothorax.

FIGURE 9-56  Simulated pneumothorax produced by poor positioning in lateral projection.



The Soft Tissues of the Thorax  |  THE PLEURA

811

FIGURE 9-58  Simulated basal pneumothorax produced by high position of the stomach anteriorly.

FIGURE 9-59  Blunted costophrenic angles in children and young adults are often seen as an apparently normal, incidental, and inconsistent finding that many times cannot be reproduced on repeat studies performed the same day. It is frequently misinterpreted as evidence of pathologic pleural effusion or pleuritis. It may be caused by redundancy of the pleura or may represent the pleural fluid normally present in the pleural space in healthy children and possibly in young adults. (Ref: Eklof O, Torngren A: Pleural fluid in healthy children. Acta Radiol Diagn 11:346, 1971.)

812

The Soft Tissues of the Thorax  |  THE PLEURA

A

B

FIGURE 9-60  A, Simulated subpulmonic effusion as evidenced by increased distance between the stomach air bubble and the dome of the diaphragm. B, The apparent separation is caused by the marked posterior position of the fundus of the stomach with projection of the diaphragm above.

A

B

FIGURE 9-61  A, B, Simulated subpulmonic effusion caused by depression of the diaphragm by the heart. The left lateral decubitus film was negative for effusion.



The Soft Tissues of the Thorax  |  THE PLEURA

813

FIGURE 9-62  Simulated basal pneumothorax in a patient with emphysema. CT scan was negative for pneumothorax. FIGURE 9-63  The posterior sulcus of the diaphragm simulating calcification of the pleura over the dome of the diaphragm.

A

B FIGURE 9-64  A, B, Pleural reflection over the inferior vena cava, which explains the shadow seen on the lateral view.

814

The Soft Tissues of the Thorax  |  THE PLEURA

A

B

FIGURE 9-65  A, B, Triangular area of relative obliteration of the diaphragm, said to be caused by extension of the areolar tissue into the base of the inferior pulmonary ligament. (Ref: Proto AV, Speckman JM: The left lateral radiograph of the chest: Part I. Med Radiogr Photogr 55:29, 1979.)

FIGURE 9-66  Four examples of the aortic pulmonary stripe, a reflection of the mediastinal pleura from the aorta to the pulmonary artery. This stripe should not be confused with displacement of the mediastinal pleura caused by adenopathy. (From Keats TE: The aortic-pulmonary mediastinal stripe. Am J Roentgenol Radium Ther Nucl Med 116:107, 1972.)



The Soft Tissues of the Thorax  |  THE PLEURA

815

FIGURE 9-67  The left paratracheal reflection. This shadow (black arrows) is seen medial to the left subclavian reflection (white arrowheads). This finding is produced by contact of the lung with the mediastinum anterior to the left subclavian artery. (Ref: Proto AV, et al: The left paratracheal reflection. Radiology 171:625, 1989.)

D

C

B

A

E

F

FIGURE 9-68  A through F, Six examples of azygos lobes to demonstrate the variation in configuration of the pleural line (m) and the position and size of the azygos vein (m 66). Note the opacity of azygos lobes in illustrations D, E, which may be mistaken for disease. (Ref: Caceras J, et al: Increased density of the azygos lobe on frontal chest radiographs simulating disease: CT scan findings in seven patients. AJR Am J Roentgenol 160:245, 1993.)

816

The Soft Tissues of the Thorax  |  THE PLEURA

FIGURE 9-69  Additional examples of azygos lobes to demonstrate the variation in configuration of the pleural line (m) and the position and size of the azygos vein (m 6 ).

FIGURE 9-70  The azygos lobe and arch and its continuity with the azygos vein (arrows).



The Soft Tissues of the Thorax  |  THE PLEURA

817

B

A

C

FIGURE 9-71  Unusual lateral position of the azygos fissure and azygos vein simulating long nodule. A, Plain film. B, CT scan section showing azygous fissure. C, CT scan section showing azygos vein.

FIGURE 9-72  Unusual azygos lobe.

818

The Soft Tissues of the Thorax  |  THE PLEURA

FIGURE 9-73  The lingular fissure. This fissure separates the lingula from the remainder of the left upper lobe (m). It duplicates the minor fissure on the right (m 66). (Ref: Boyden EA: Cleft left upper lobes and the split anterior bronchus. Surgery 26:167, 1949.)

FIGURE 9-74  Two examples of an accessory fissure of the left upper lobe, the left “azygos lobe.” (Ref: Takasugi JE, Goodwin JD: Left azygos lobe. Radiology 171:133, 1989.)



The Soft Tissues of the Thorax  |  THE PLEURA

819

FIGURE 9-75  The superior accessory fissure of the left lower lobe. This fissure separates the superior and basal segments of the left lower lobe. A similar fissure occurs in the right lower lobe. (Ref: Felson B: The lobes and interlobar pleura: Fundamental roentgen considerations. Am J Med Sci 230:572, 1955.)

FIGURE 9-76  Superior accessory fissure by plain film (left) and with pneumothorax (right).

FIGURE 9-77  Cephalic curvature of the minor interlobar fissure may be seen as a normal variation.

820

The Soft Tissues of the Thorax  |  THE PLEURA

FIGURE 9-78  Accessory fissure for the superior segment of the right lower lobe. Note the presence of two pleural lines in the frontal projection. (Ref: Godwin JD, Tarver RD: Accessory fissures of the lung. AJR Am J Roentgenol 144:39, 1985.)

FIGURE 9-80  Superimposed scapular spines may simulate interlobar pleural surfaces.

FIGURE 9-79  Minor fissure may normally be seen posteriorly in films made with slight rotation and may be mistaken for the accessory fissure seen in Figure 9-78.

FIGURE 9-81  Inferior accessory fissure. When complete, it isolates the medial basal segment of the lower lobe. (Ref: Felson B: The lobes and interlobar pleura: Fundamental roentgen considerations. Am J Med Sci 230:572, 1955.)



The Soft Tissues of the Thorax  |  THE PLEURA

FIGURE 9-82  Sagittal orientation of the major fissure. Note how it may simulate pneumopericardium. (Ref: Gross BH, et al: Sagittal orientation of the anterior minor fissure: Radiography and CT. Radiology 166:717, 1988.)

A

821

FIGURE 9-83  Vertical fissure line. This line represents the caudal end of the major interlobar fissure. It may be seen in films of healthy children when it is ectopic and lies forward so part of it is in axial projection. It should not be mistaken for a pneumothorax. (Ref: Davis LA: The vertical fissure line. Am J Roentgenol Radium Ther Nucl Med 84:451, 1960.)

B

FIGURE 9-84  Vertical fissure line. A, Unilateral. B, Bilateral. (Ref: Webber MM, O’Loughlin BJ: Variations of the pleural vertical fissure line. Radiology 82:461, 1964.)

822

The Soft Tissues of the Thorax  |  THE PLEURA

A

FIGURE 9-85  Vertical fissure line with extension over the apex of the right lower lobe.

B FIGURE 9-86  Pleural reflection over the inferior vena cava. A, Apparent paraspinous mass (m) produced by pleural reflection over the inferior vena cava (m 66). B, Detailed view with greater penetration shows no paraspinous mass.

A

B

FIGURE 9-87  Esophageal pleural stripe that represents the right esophageal wall and its adjacent pleural covering. A, Plain film. B, Esophagram. (Ref: Cimmino CV: The esophageal-pleural stripe on chest teleroentgenograms. Radiology 67:754, 1956.)



FIGURE 9-88  Posterior mediastinal stripe, the interface of the right and left lungs, seen in frontal projection. (Ref: Cimmino CV, Snead LO Jr: The posterior mediastinal line on chest roentgenograms. Radiology, 84:516, 1965.)

FIGURE 9-90  Anterior mediastinal stripe representing the interface between the right and left lungs, seen in frontal projection. (Ref: Cimmino CV: The anterior mediastinal line on chest roentgenograms. Radiology 82:459, 1964.)

The Soft Tissues of the Thorax  |  THE PLEURA

823

FIGURE 9-89  Posterior mediastinal line seen in its entirety.

FIGURE 9-91  Anterior mediastinal stripe and its lateral extensions.

824

The Soft Tissues of the Thorax  |  THE LUNGS

THE LUNGS

FIGURE 9-92  Bulging of the interspaces in a normal child. Although intercostal bulging of the lung is said to be an early sign of obstructive emphysema, it may also be seen in normal, thin children who inspire fully. (Ref: Kattan KR, et al: Intercostal bulging of the lung without emphysema. Am J Roentgenol Radium Ther Nucl Med 112:542, 1971.)

A

FIGURE 9-93  Scapulae seen in lordotic projection may simulate pulmonary disease (m), particularly the shadow of the spine of the scapula (m 66).

B

FIGURE 9-94  Films made of infants in isolettes may show radiolucencies produced by the opening in the isolette covers. These may simulate abnormalities such as air cysts, as in A, or pneumopericardium, as in B.

A

B

FIGURE 9-95  A, Simulated pneumonia produced by pectoral muscle shadows with the subject’s arms down. B, On film made 5 minutes later with the subject’s arms elevated, pectoral shadows have disappeared.



The Soft Tissues of the Thorax  |  THE LUNGS

A

B

FIGURE 9-96  A, B, Breast shadows simulating pulmonary consolidation in the lateral projection (B).

FIGURE 9-97  Simulated consolidation of the lung produced by superimposed breast shadows.

825

826

The Soft Tissues of the Thorax  |  THE LUNGS

FIGURE 9-98  Dense calcification of the costal cartilages mistaken for a left lower lobe consolidation or atelectasis in the frontal film.

FIGURE 9-99  Costal cartilage calcification of the first rib, not to be mistaken for parenchymal lesions.

FIGURE 9-100  Two examples of hair braids simulating parenchymal abnormality.



The Soft Tissues of the Thorax  |  THE LUNGS

A

827

B

FIGURE 9-101  Filming infant chests in even minor degrees of expiration may result in misinterpretation caused by the marked opacity of the parenchyma, as illustrated in this normal infant. A, Expiration. B, Inspiration.

FIGURE 9-102  Expiratory film with superimposition of the right hemidiaphragm on the heart, producing an image simulating atelectasis of the right middle lobe.

A

B FIGURE 9-103  Filming in expiration may simulate basal pneumonitis in the adult. A, Expiration. B, Inspiration

828

The Soft Tissues of the Thorax  |  THE LUNGS

FIGURE 9-104  Simulated air trapping in the right middle lobe. This misleading appearance is not uncommon and results from the pattern of division of the major vascular trunks. There is no evidence of air trapping in the lateral projection. (Refs: Goodman LR, et al: The right midlung window. Radiology 143:135, 1982.)

A

B

FIGURE 9-105  Effects of respiration on the trachea in infancy. The trachea (m) widens on inspiration (A) and narrows on expiration (B). The hatched arrows (m 66) in B indicate swallowed air in the esophagus. Note also the normal anterior buckling of the airway in the neck on expiration (m 6). (Ref: Wittenborg MH, et al: Tracheal dynamics in infants with respiratory distress, stridor, and collapsing trachea. Radiology 88:653, 1967.)



The Soft Tissues of the Thorax  |  THE LUNGS

FIGURE 9-106  Tracheal narrowing on expiration in a 3-week-old infant, illustrating how marked this physiologic event may normally be.

A

829

FIGURE 9-107  Normal anterior tracheal indentation in a 2-year-old child. This is a common finding just below the thoracic inlet. It changes with respiration and is usually of no clinical significance: There is evidence that it is the product of intermittent cephalic movement of the thymus from the anterior mediastinum into the neck with respiration. It is seen commonly in children younger than 2 years. (Refs: Swischuk LE: Anterior tracheal indentations in infancy and early childhood. Normal or abnormal? Am J Roentgenol Radium Ther Nucl Med 112:12, 1971; Mandell CA, et al: Cervical trachea: Dynamics in response to herniation of the normal thymus. Radiology 186:383, 1993.)

B

FIGURE 9-108  A shallow impression on the right side of the trachea at the thoracic inlet is seen in many normal children (A) and adults (B).

830

The Soft Tissues of the Thorax  |  THE LUNGS

FIGURE 9-109  Lateral buckling of the trachea at the thoracic inlet occurs normally in infants and children up to 5 years of age. The displacement is to the side opposite the aortic arch and is best seen in expiration. (Ref: Chang LW, et al: Normal lateral deviation of the trachea in infants and children. Am J Roentgenol Radium Ther Nucl Med 109:247, 1970.)

FIGURE 9-110  Deviation of the trachea to the left in the presence of a right aortic arch.



The Soft Tissues of the Thorax  |  THE LUNGS

A

831

B

FIGURE 9-111  A, Tracheal buckling on expiration in an adult. B, Inspiration does not show buckling.

FIGURE 9-112  Indentation on the right side of the trachea above the thoracic inlet. CT scan showed bucking of the trachea at this level. This is a normal phenomenon. FIGURE 9-113  Shift of the mediastinum to the right in the supine position. CT scan findings were normal.

832

The Soft Tissues of the Thorax  |  THE LUNGS

FIGURE 9-114  Normal anterior bowing of the trachea in the adult, associated with ectasia of the aorta.

FIGURE 9-116  “Physiologic” calcification of the tracheobronchial cartilages in a 56-year-old woman. Tracheal calcification is a feature seen particularly in elderly women. (Ref: Kurihara Y, et al: Radiologic evidence of sex differences: Is the patient a man or a woman? AJR Am J Roentgenol 167:1037, 1996.

FIGURE 9-115  Calcification of cartilaginous rings in a healthy 47-yearold woman. This finding is unusual except in old age, unless the patient has hypercalcemia or hyperphosphatemia.

FIGURE 9-117  Superimposition of the scapulae simulating thickening of the paratracheal soft tissues.



The Soft Tissues of the Thorax  |  THE LUNGS

833

FIGURE 9-118  Left, Portable chest films that are made with lordotic projection will produce an illusory consolidation of the left lower lobe, with loss of the medial portion of the left hemidiaphragm. Right, Film made with proper projection does not show the pseudoconsolidation. (Ref: Zylak CJ, et al: Illusory consolidation of the left lower lobe: A pitfall in portable radiology. Radiology 167:653, 1988.)

FIGURE 9-119  Two examples of large transverse processes that simulate nodular pulmonary lesions.

FIGURE 9-120  Large hypertrophic spur simulating a parenchymal lesion in both frontal and lateral projections.

834

The Soft Tissues of the Thorax  |  THE LUNGS

FIGURE 9-122  Transverse processes producing nodular shadows. FIGURE 9-121  Hypertrophic spurs simulating lung nodules.

FIGURE 9-123  Hypertrophic spur simulating a lung nodule. Left, Lateral projection. Right, CT scan.



The Soft Tissues of the Thorax  |  THE LUNGS

835

FIGURE 9-124  Left, Large transverse process simulating a lung nodule. Right, Film made with slight rotation does not reproduce the pseudonodule.

FIGURE 9-125  Two examples of hypertrophy of interarticulating facets producing pseudonodules.

FIGURE 9-126  Vertebral hypertrophic spurs may simulate pulmonary lesions.

836

The Soft Tissues of the Thorax  |  THE LUNGS

FIGURE 9-127  Neural arches simulating lung nodules.

FIGURE 9-128  Soft tissues of the arm seen in lateral projection, simulating atelectasis of the upper lobe.

FIGURE 9-129  Prominent nipple shadow in a man simulating a nodular pulmonary lesion.

FIGURE 9-130  Nipple shadows can cause confusing images in the lateral projection when patients are poorly positioned.



The Soft Tissues of the Thorax  |  THE LUNGS

FIGURE 9-131  Skin lesions may produce nodular shadows that simulate parenchymal nodules, in this case a large nevus.

FIGURE 9-132  Two examples of simulated cavitary lesions produced by superimposition of vascular shadows. This phenomenon is common in the perihilar areas.

837

838

The Soft Tissues of the Thorax  |  THE LUNGS

FIGURE 9-133  Apical opacities produced by the subclavian arteries that may be mistaken for a parenchymal abnormality. (From Proto AV: Conventional chest radiographs: Anatomic understanding of newer observations. Radiology 183:593, 1992.)

FIGURE 9-134  Same entity as illustrated in Figure 9-133.

FIGURE 9-135  Simulated nodule produced by branches of the aortic arch. (Ref: Caceras J, et al: Pulmonary nodules simulated on the lateral chest radiograph by branches of the aortic arch. AJR Am J Roentgenol 151:465, 1988.)

FIGURE 9-136  Pseudolesion of the lung produced by superimposition of normal upper lobe vascular structures on the arch of the aorta (see Fig. 9-156). (Ref: Stark P, et al: Pseudolesion of the chest: A conglomerate shadow on the lateral radiograph. Chest 87:541, 1985.) (See also Figs. 9-135 and 9-156.)



The Soft Tissues of the Thorax  |  THE LUNGS

839

FIGURE 9-137  Rhomboid fossa of the clavicle simulating a cavitary lesion of the right upper lobe.

FIGURE 9-138  Shadows of the subclavian arteries may simulate a pleural or parenchymal density.

A

B

FIGURE 9-139  Films made in expiratory phases of respiration show greater prominence of the pulmonary arteries (m) and the confluence of the pulmonary veins (m 6 ). Note also the vascular prominence in the posterior base in A (m 66). The shadow of these vessels is often misinterpreted as evidence of pneumonitis. The problem does not present itself in films made with good inspiration, as in B.

840

The Soft Tissues of the Thorax  |  THE LUNGS

FIGURE 9-140  Pulmonary veins in lateral projection may assume a somewhat nodular configuration.

FIGURE 9-141  Simulated hiatal hernia in retrocardiac space in a child, produced by the inferior vena cava anteriorly and vessels posteriorly.



The Soft Tissues of the Thorax  |  THE LUNGS

A

C

B

D

FIGURE 9-142  Confluence of the pulmonary veins at the left atrium may manifest as a nodular density, which should not be confused with a mass lesion. A, Plain frontal film. B, Oblique projection. C, Frontal tomogram. D, Lateral tomogram.

841

842

The Soft Tissues of the Thorax  |  THE LUNGS

FIGURE 9-143  Confluence of the pulmonary veins.

FIGURE 9-144  Scimitar vein, an anomalous vessel that drains into the inferior vena cava below the diaphragm. This vein may be an isolated finding, as in this case, or may be associated with hypoplasia of the right lung. (Ref: Roehm JO Jr, et al: Radiographic features of the scimitar syndrome. Radiology 86:856, 1966.)



The Soft Tissues of the Thorax  |  THE LUNGS

A

843

B

FIGURE 9-145  Mucus plugs in the trachea may simulate significant lesions, such as neoplasms. A, Tomogram of the trachea, showing filling defect. B, Tomogram after patient coughed up a mucus plug. (Ref: Karasick D, et al: Mucoid pseudotumors of the tracheobronchial tree in two cases. AJR Am J Roentgenol 132:459, 1979.)

FIGURE 9-146  Arterial shadow superimposed on the bronchus simulating a broncholith.

844

The Soft Tissues of the Thorax  |  THE LUNGS

A

B

FIGURE 9-147  A, The azygos lobe may simulate an infiltrate in a standard frontal film. B, Same area seen in lordotic projection, showing the usual appearance of the azygos lobe.

FIGURE 9-148  Unusual configuration of the azygos lobe, which may simulate a parenchymal lesion.



The Soft Tissues of the Thorax  |  THE LUNGS

A

845

B

C FIGURE 9-149  A, Tracheal bronchus seen on plain film. B, CT scan section showing the tracheal bronchus. C, CT scan section below B, at the level of the tracheal bifurcation.

A

B FIGURE 9-150  Tracheal bronchus shown by MR image. A, Coronal image. B, Axial image.

846

The Soft Tissues of the Thorax  |  THE MEDIASTINUM

THE MEDIASTINUM

FIGURE 9-151  Arm fold superimposed on anterior mediastinum producing a mass effect. (Ref: Vaezy A, Delaney DJ: Chest wall mass mimicking pulmonary tumor. South Med J 72:499, 1979.) FIGURE 9-152  Scapula and arm fold producing a simulated lucent mass.

A

B

FIGURE 9-153  A, Spurious widening of the mediastinum produced by lordotic projection. B, Conventional posteroanterior projection shows a normal appearance. (Ref: Hollman AJ, Adams FG: Lordotic projectional widening of the mediastinum. Clin Radiol 40:360, 1989.)



The Soft Tissues of the Thorax  |  THE MEDIASTINUM

A

847

B

FIGURE 9-154  A, Superimposition of a rib shadow on the aortic arch simulates an air-fluid level. B, The top of the arch of the aorta may simulate an air-fluid level in the esophagus.

FIGURE 9-155  Spine of the scapula simulating a cavitary lesion with an air-fluid level.

848

The Soft Tissues of the Thorax  |  THE MEDIASTINUM

FIGURE 9-157  Angle of the scapula simulating a lung nodule.

FIGURE 9-156  Superimposition of the shadows of the aorta and scapula produces a triangular shadow of increased density (see Fig. 9-136).

FIGURE 9-158  Examples of the retrosternal line produced by the interface between the two lungs and the mediastinal fat. (Ref: Whalen JP, et al: The retrosternal line: A new sign of an anterior mediastinal mass. Am J Roentgenol Radium Ther Nucl Med 117:861, 1973.)



The Soft Tissues of the Thorax  |  THE MEDIASTINUM

849

FIGURE 9-159  Left, Prominent retrosternal line. Right, CT scan shows the mechanism of production of the line. The right lung extends to the anterior chest wall. The left lung is excluded by the heart and mediastinal fat (m). The difference in anterior extension of the two lungs creates the retrosternal line.

A

B

FIGURE 9-160  A, Unusually prominent retrosternal line produced by rotation at the time of filming. B, True lateral projection shows a usual appearance.

850

The Soft Tissues of the Thorax  |  THE MEDIASTINUM

FIGURE 9-162  Superimposition of the ribs and the retrosternal line producing a pseudomass.

FIGURE 9-161  Very prominent retrosternal line.

FIGURE 9-163  In some individuals with well-defined retrosternal lines, an additional line (the right parasternal stripe) may be seen through the right side of the heart. This line indicates the medial edge of the right lung. (Ref: Keats TE: The right parasternal stripe: A new mediastinal shadow and a contribution to the nature of the retrosternal line. Am J Roentgenol 120:898, 1974.)



The Soft Tissues of the Thorax  |  THE MEDIASTINUM

851

FIGURE 9-164  Three examples of clinically unimportant triangular radiolucencies in the anterior mediastinum in adults. The mechanism of production of these shadows is not proven, but they are probably the result of the same anatomy that produces the retrosternal line, illustrated in Figure 9-159.

FIGURE 9-165  Five examples of triangular anterior mediastinal radiolucencies seen in young children with large thymuses. These radiolucencies may represent the same entity illustrated as in Figure 9-164 or are possibly related to the presence of the thymus. (Ref: Quattromani FL, et al: Fascial relationship of the thymus: Radiologic-pathologic correlation in neonatal pneumomediastinum. AJR Am J Roentgenol 137: 1209, 1981.)

852

The Soft Tissues of the Thorax  |  THE MEDIASTINUM

FIGURE 9-166  Sternal ossification centers in an infant, which may be confused with mediastinal masses.

FIGURE 9-167  A, Simulated pneumomediastinum produced by sternal retraction. B, Follow-up film shows normal appearance.

A

B

FIGURE 9-168  The anterior extrapleural line represents a deviation of the pleura produced by the innominate artery and vein and the costal cartilages of the first ribs. It should not be mistaken for a lesion of the sternum or a mediastinal mass. (Ref: Whalen JP, et al: Anterior extrapleural line: Superior extension. Radiology 115:525, 1975.) FIGURE 9-169  The manubrium, simulating a mediastinal mass (m), is produced by slight scoliosis. The azygos arch is seen below (m 66).



The Soft Tissues of the Thorax  |  THE MEDIASTINUM

A

853

B

FIGURE 9-170  The anterior extrapleural line in a child, which was misinterpreted as a mass lesion. A, Conventional film. B, Xerogram.

FIGURE 9-171  Two examples of mediastinal fat, producing widening of the mediastinum. This finding may be seen in obesity, in Cushing’s disease, and in patients receiving steroids. (Ref: Price JE Jr, Rigler LG: Widening of the mediastinum resulting from fat accumulation. Radiology 96:497, 1970.) Seen in lateral projection, such fat may simulate the thymus. (Ref: Steckel RJ: Mediastinal pseudotumors associated with exogenous obesity. Radiology 119:74, 1976.)

FIGURE 9-172  CT scan showing extensive mediastinal lipomatosis.

854

The Soft Tissues of the Thorax  |  THE MEDIASTINUM

FIGURE 9-173  Alterations in configuration of the mediastinum over a period of 25 years as a result of mediastinal fat deposition. An azygos lobe is present.

A

B

FIGURE 9-174  A, B, Progressive mediastinal lipomatosis over a 10-year period secondary to steroids. Note displacement of the aortic pulmonary stripe in B (m).



The Soft Tissues of the Thorax  |  THE MEDIASTINUM

855

FIGURE 9-175  Mediastinal lipomatosis with marked displacement of the aortic pulmonary stripe.

FIGURE 9-176  Mediastinal lipomatosis displacing the aortic pulmonary stripe above the level of the aortic arch.

FIGURE 9-177  Mediastinal lipomatosis producing mediastinal linear densities.

856

The Soft Tissues of the Thorax  |  THE MEDIASTINUM

FIGURE 9-178  Mediastinal fat simulating a dilated ascending aorta.

A

B

FIGURE 9-179  A, Extension of mediastinal fat into the medial aspect of the minor interlobar fissure. B, Follow-up film obtained 4 years later.



The Soft Tissues of the Thorax  |  THE MEDIASTINUM

FIGURE 9-180  Mediastinal fat paralleling the left mediastinal border.

FIGURE 9-181  Fat seen in the anterior mediastinum, which increased over a 2-year period of progressive obesity.

857

858

The Soft Tissues of the Thorax  |  THE MEDIASTINUM

FIGURE 9-182  Mediastinal lipomatosis. Note also the extension of the fat over the apex of the lungs and into the extrapleural spaces (m).

FIGURE 9-183  Left, Confusing appearance produced by mediastinal lipomatosis (m) and an azygos lobe (m 6 ). Right, CT scan shows the course of the azygos vein.



The Soft Tissues of the Thorax  |  THE MEDIASTINUM

A

B

FIGURE 9-184  A, Widening of the right side of the mediastinum produced by distention of the superior vena cava after forceful Valsalva maneuver. B, Film of same patient in suspended respiration without Valsalva maneuver.

A

B FIGURE 9-185  Azygos lobe simulating a distended, air-filled esophagus. A, Plain film. B, Tomogram.

859

860

The Soft Tissues of the Thorax  |  THE MEDIASTINUM

FIGURE 9-186  Widening of the superior mediastinum produced by anomalous venous drainage of the left upper lobe. The anomalous vertical vein is evident. (Ref: Adler SC, Silverman JF: Anomalous venous drainage of the left upper lobe. Radiology 108:563, 1973.)

FIGURE 9-187  The spurious posterior mediastinal mass, seen in infants as the result of superimposition of the scapulae and the axillary soft tissues, combined with the anterior curve of the trachea and the lower lobe continuation of the left main bronchus. (Refs: Alazraki NP, Friedman PJ: Posterior mediastinal “pseudo-mass” of the newborn. Am J Roentgenol Radium Ther Nucl Med 116:571, 1972; Balsam D, et al: The scapula as a cause of spurious posterior mediastinal mass on lateral chest films of infants. J Pediatr Surg 9:501, 1974.)

FIGURE 9-188  A, The pseudomass of the mediastinum in infants, illustrated in Figure 9-187, is accentuated by filming in the expiratory phase of respiration. B, In full inspiration, no mass effect is seen.

A

B



The Soft Tissues of the Thorax  |  THE MEDIASTINUM

FIGURE 9-189  Posterior mediastinal pseudomass in an adult.

FIGURE 9-191  Normal left paravertebral soft tissues. Arrow indicates the paravertebral stripe; hatched arrow indicates the descending aorta. (Ref: Lien HH, Kolbenstvedt A: The thoracic paraspinal shadow: Normal appearances. Clin Radiol 33:31, 1982.) Occasionally one may see a localized loss of the infrabronchial descending aortic interface as a normal variant. (Ref: van Gelderen WF: Localized loss of the infrabronchial descending interface as a normal variant. Br J Radiology 65:865, 1992.)

861

FIGURE 9-190  Normal paravertebral stripe. Note that the stripe is not normally seen in the upper thoracic region, being lost at T4–T5; this appearance is best seen in the patient on the right.

FIGURE 9-192  The left paramediastinal stripe (m), representing the reflection of the pleura against the spine, may be deviated laterally by ectasia of the thoracic aorta (m 6 ) and is therefore not necessarily an indication of vertebral or mediastinal abnormality. (Ref: Genereux GP: The posterior pleural reflections. AJR Am J Roentgenol 141:141, 1983.)

862

A

The Soft Tissues of the Thorax  |  THE MEDIASTINUM

B

C

FIGURE 9-193  Paravertebral stripe may be seen on the right, particularly in young individuals (A, B), or bilaterally (C), and should not be confused with a paraspinous mass. A similar shadow on the right may also be caused by a wide inferior vena cava. (Ref: Eklof O, et al: Malignant versus benign paravertebral widening in children. Pediatr Radiol 11:193, 1981.)

FIGURE 9-194  Right and left paravertebral stripes in a 49-year-old woman.

FIGURE 9-195  Displacement of the right paravertebral stripe by hypertrophic lipping of the spine.



The Soft Tissues of the Thorax  |  THE MEDIASTINUM

FIGURE 9-196  A very narrow chest results in striking visualization of both paravertebral stripes.

FIGURE 9-197  Visualization of the right paravertebral stripe in an individual with a narrow chest.

863

864

The Soft Tissues of the Thorax  |  THE MEDIASTINUM

A

B

FIGURE 9-198  Paraspinous fat deposition displaces the paravertebral stripes. A, Plain film. B, CT scan. (Refs: Streiter ML, et al: Steroid-induced thoracic lipomatosis: Paraspinal involvement. AJR Am J Roentgenol 139:679, 1982; Glickstein MC, et al: Paraspinal lipomatosis. Radiology 163:79, 1987.)

FIGURE 9-199  Left, Striking paraspinal lipomatosis that is bilaterally symmetric. Right, CT scan.

A

B

FIGURE 9-200  Marked obesity resulting in displacement of the paravertebral stripe by fat deposition. A, A 300-lb, 14-year-old boy. B, A 250-lb, 46-year-old man.



The Soft Tissues of the Thorax  |  THE MEDIASTINUM

FIGURE 9-201  Paraspinous fat deposits may not be evenly distributed or symmetric, as illustrated in this case. Left, Plain film. Right, CT scan.

FIGURE 9-202  Origin of the psoas muscles from the lower thoracic spine producing paraspinous soft tissue shadows.

865

866

The Soft Tissues of the Thorax  |  THE MEDIASTINUM

A

B

C

D

FIGURE 9-203  Thoracic origin of very large psoas muscles producing paravertebral soft tissue bulges. A, B, Frontal projections. C, D, Oblique projections.



The Soft Tissues of the Thorax  |  THE MEDIASTINUM

867

FIGURE 9-204  Four examples of discrete left paravertebral soft tissue bulges that have not been demonstrable on CT scan or aortography. In some pathologic states, similar shadows may be seen related to the hemiazygos system. These shadows may be the product of intermittent filling of veins. (Ref: Castellino RA, et al: Dilated azygous and hemiazygous veins presenting as paravertebral intrathoracic masses. N Engl J Med 278:1087, 1968.) A similar shadow may be produced by a mediastinal lymph node (see Fig. 9-205).

868

The Soft Tissues of the Thorax  |  THE MEDIASTINUM

FIGURE 9-205  PA and right anterior oblique views of the chest showing a calcified mediastinal lymph node producing a shadow similar to those illustrated in Figure 9-204.

A

B

FIGURE 9-206  A, Simulated pneumomediastinum appears as a radiolucency adjacent to the aorta, which is produced by lucent lung in the interval between the aorta and adjacent pulmonary vessels. B, With slight rotation to the left, the nature of this pseudolesion lesion is evident.



The Soft Tissues of the Thorax  |  THE MEDIASTINUM

A

869

B

FIGURE 9-207  A, Simulated pneumomediastinum evidenced by a lucent halo around the heart produced by the Mach effect. B, No evidence of pneumomediastinum is seen in lateral projection. (Ref: Friedman AC, et al: Mach bands and pneumomediastinum. J Can Assoc Radiol 32:232, 1981.)

FIGURE 9-208  Simulated pneumomediastinum in an infant produced by slight rotation of the chest at the time of filming, which projects lucent lung in front of the cardiac shadow.

FIGURE 9-209  Air in the esophagus producing a lucency beneath the aortic arch (m). This is seen when the esophagus is displaced to the left by adhesions to a tortuous aorta. Barium may be retained in this pocket as well. Note the position of the pleural esophageal reflection (m 66). (Ref: Cimmino CV: A roentgenologic study in mediastinal anatomy affected by air in the midesophagus. Am J Roentgenol 94:333, 1965.)

870

The Soft Tissues of the Thorax  |  THE MEDIASTINUM

FIGURE 9-210  Three examples of patients with transient reflux of gas in the esophagus that should not be confused with mediastinal gas. (Ref: Proto A, Lane KJ: Air in the esophagus: A frequent radiographic finding. AJR Am J Roentgenol 129:433, 1977.)

A

B

C

FIGURE 9-211  A, C, Examples of air trapped in the midesophagus (m), as illustrated in Figure 9-209. Note in A that the shift of the esophagus to the left has permitted a portion of the right lung to cross the left side, producing an additional area of radiolucency (m 6 ). B, Barium esophagram of the patient shown in A. Note that the knuckle in the aorta corresponds to the air shadow in the plain film. (Ref: Proto AV, Lane EJ: Air in the esophagus: A frequent radiologic finding. AJR Am J Roentgenol 129:433, 1977.)



The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

FIGURE 9-212  Marked example of air in the esophagus.

THE HEART AND GREAT VESSELS

A FIGURE 9-213 

B The azygos arch may be seen in the lateral projection as a nodular density, immediately behind the trachea. A, Child. B, Adult.

871

872

A

The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

B

C

FIGURE 9-214  Shadows of the normal azygos vein. A, Arch of the azygos vein. B, Posterior portion of the azygos arch, the “azygos knob.” C, Posterior portion of the azygos arch shown on a tomogram. (Ref: Heitzman ER, et al: The azygos vein and its pleural reflections. I: Applications in the radiologic diagnosis of mediastinal abnormality. Radiology 101:259, 1971.)

FIGURE 9-216  On tomography, the azygos knob may simulate an intratracheal mass. (Ref: Austin JHM, Thorsen MK: Normal azygous arch: Retrotracheal visualization on frontal chest tomograms. AJR Am J Roentgenol 137:1205, 1981.) FIGURE 9-215  The azygos knob may be seen without tomography.



The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

FIGURE 9-217  Azygopulmonary recess (m). Hatched arrow (m 6 ) indicates the posterior portion of the azygos arch.

FIGURE 9-218  The azygos arch seen in lateral projection on tomograms.

873

874

The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

FIGURE 9-219  A catheter has been placed in the azygos vein. Note the coincidence of the catheter position with the shadows seen in the lateral projection in Figures 9-213 and 9-218.

FIGURE 9-220  In congenital absence of the inferior vena cava with azygos continuation, the arch of the azygos vein is large and may be mistaken for a mediastinal mass. (Refs: Heller RM, et al: A useful sign in the recognition of azygos continuation of the inferior vena cava. Radiology 101:519, 1971; Pallin J et al: Azygos continuation of the inferior vena cava masquerading as neoplasm. South Med J 82:259, 1989.)



The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

875

FIGURE 9-221  Proportional difference between the sizes of the heart and thorax in a newborn (right) and an adult (left). In infancy, the heart occupies a proportionately larger area of the thorax than in adulthood, and adult criteria for heart size cannot be applied to infants and children. (From Keats TE: Pediatric radiology: Some potentially misleading variations from the adult. Va Med Mon 93:630, 1966.)

A

B

FIGURE 9-222  Normal variability in heart size with changes in the cardiac cycle in a child. A, Systole. B, Diastole.

876

The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

FIGURE 9-223  Normal variability in heart size with changes in the cardiac cycle in the adult. A, Systole. B, Diastole.

A

B

FIGURE 9-224  Left, Heart movements during filming may produce a confusing double contour of the left heart border, representing systole (m) and diastole (m 6). Right, The same effect may be seen during tomography in another patient.

FIGURE 9-225  Decrease in heart size resulting from the Valsalva effect. Left, Baseline. Right, after the Valsalva maneuver.



The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

FIGURE 9-226  Shadows of the bronchus and pulmonary vessel adjacent to the right heart border simulate pneumopericardium.

FIGURE 9-227  Large thymus simulating cardiomegaly. Note the normal heart size in the lateral projection.

877

878

The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

FIGURE 9-228  Very small hearts are not necessarily of significance and are often seen in young, asthenic women. (Ref: Swischuk LE: Microcardia: An uncommon diagnostic problem. Am J Roentgenol Radium Ther Nucl Med 103:115, 1968.)

FIGURE 9-229  Pseudomyocardial aneurysm of the posterior wall of the left ventricle. A, A discrete bulge is seen on the posterior wall of the left ventricle that is not seen in an exposure made later in the same session (B). This bulge is seen fluoroscopically and shows apparent paradoxic movement. It represents a transient phase of contraction of the left ventricle late in systole and is a normal phenomenon. (From Keats TE, Martt JM: False paradoxic movement of the posterior wall of the left ventricle simulating myocardial aneurysm. Radiology 78:381, 1962.)

A

B

FIGURE 9-230  Additional example of the pseudoaneurysm of the posterior wall of the left ventricle.



The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

879

FIGURE 9-231  Four examples of the visualization of the right border of the left atrium in normal children. This border may be seen also in adults and should not be taken as evidence of left atrial enlargement in itself, unless correlative evidence is present in the other projections. (Ref: Rosario-Medina W, et al: Normal left atrium: Appearance in children on frontal chest radiographs. Radiology 161:345, 1986.)

FIGURE 9-233  Elevation of the cardiac apex in a normal 2-year-old child produced by very deep inspiration. This configuration should not be confused with the alteration caused by ventricular hypertrophy. FIGURE 9-232  The normal left atrium in a 19-year-old woman.

880

The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

FIGURE 9-234  Two examples of the subepicardial fat line seen as a lucent crescent beyond the heart shadow (m). The pericardium (m 66) is sandwiched between the subepicardial fat and the epicardial fat. (Ref: Lane EJ Jr, Carsky EW: Epicardial fat: Lateral plain film analysis in normals and in pericardial effusion. Radiology 91:1, 1968.)

FIGURE 9-235  Subepicardial fat, which could be mistaken for pneumopericardium, seen in frontal and lateral projections in a 7-year-old boy. (Ref: Kremens V: Demonstration of pericardial shadow on routine chest roentgenogram: A new roentgen finding—preliminary report. Radiology 64:72, 1955.)

FIGURE 9-236  Congenital absence of the left pericardium. This appearance is quite characteristic. The heart is shifted to the left in the absence of pectus excavatum of the sternum, and there is a large bulge in the left contour of the heart in the area normally occupied by the main pulmonary artery (m). (Ref: Tabakin BJ, et al: Congenital absence of the left pericardium. Am J Roentgenol Radium Ther Nucl Med 94:122, 1965.)



The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

FIGURE 9-237  More marked example of absence of the left pericardium.

FIGURE 9-238  Visualization of the pericardium at the right side of the heart border in a 4-year-old boy on two different occasions. Its visualization is caused by the presence of subepicardial fat. The pericardial shadow should not be misinterpreted as calcification in the pericardium. (Ref: Keats TE: Four normal anatomic variations of importance to radiologists. Am J Roentgenol Radium Ther Nucl Med 78:89, 1957.)

FIGURE 9-239  Normal cardiac changes in pregnancy. A, In addition to cardiac enlargement, there is a rather selective dilatation of the right atrium in some normal women during pregnancy. In addition, the arch of the azygos vein enlarges (m). B, Regression of these changes shortly after parturition (Refs: Keats TE, Martt JM: Selective dilatation of the right atrium in pregnancy. Am J Roentgenol Radium Ther Nucl Med 91:307, 1964; Keats TE, et al: Mensuration of the azygos vein and its application to the study of cardiopulmonary disease. Radiology 90:990, 1968.)

A

B

881

882

The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

FIGURE 9-240  Straight back syndrome, producing flattening of the heart and prominence of the pulmonary artery. Individuals with congenital absence of the normal dorsal kyphosis and narrow sagittal diameter of the chest present striking alterations in cardiac contour compounded by the coexistence of physical findings that may mimic organic heart disease. (Ref: Deleon AC Jr, et al: The straight back syndrome: Clinical cardiovascular manifestations. Circulation 32:193, 1965.) Note also the partial obliteration of the descending aorta, which is an associated finding in patients with narrow chests. (Ref: Okawada T, et al: Partial obliteration or blurring of the descending aortic contours: A pitfall on plain chest radiographs. Clin Radiol 48:192, 1993.)

FIGURE 9-241  Straight back syndrome showing distortion of the aortic arch and descending aorta.



The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

883

FIGURE 9-242  Normal epipericardial fat pads. These fat collections may be confused with cysts and neoplasms. They vary in size with the weight of the patient. (Ref: Holt JF: Epipericardial fat shadows in differential diagnosis. Radiology 48:472, 1947.)

FIGURE 9-243  Unusual configuration of the epipericardial fat pad.

FIGURE 9-244  Small, discrete, round epipericardial fat pad in the right cardiophrenic angle.

884

The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

FIGURE 9-245  Additional examples of epipericardial fat pads. (Ref: Nahon JR: Roentgenologic characteristics of the epipericardial fat pad with a case report. Radiology 65:745, 1955.)

FIGURE 9-246  Increasing size of epipericardial fat pad over a 6-year period of progressive obesity.



The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

885

FIGURE 9-247  Extension of the epipericardial fat pad into the major interlobar fissure. (Ref: Gale ME, Greif WL: Intrafissural fat: CT correlation with chest radiography. Radiology 160:333, 1986.)

FIGURE 9-248  Two examples of triangular shadows at the lung base produced by extension of the epipericardial fat pad into the left major fissure anteriorly (m) and the shadow of the inferior vena cava posteriorly (m 6). (Ref: Fisher ER, Godwin JD: Extrapleural fat collections: Pseudotumors and other confusing manifestations. AJR Am J Roentgenol 161:47, 1993.)

FIGURE 9-249  Extension of an epipericardial fat pad into the minor interlobar fissure.

886

The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

A

B

FIGURE 9-250  Irregular epipericardial fat pad that was misinterpreted as a neoplasm and removed by thoracotomy (m). A, Plain film, lateral view. Note extension into the major interlobar fissure (m 6 ). B, Tomogram.

FIGURE 9-251  Left, Baseline film. Right, On film obtained 10 years later, right middle lobe atelectasis was misdiagnosed because of superimposition of an epipericardial fat pad with extension into the major interlobar fissure (m).



The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

FIGURE 9-252  Unusually large epipericardial fat pad on the right with CT scan demonstration.

887

888

The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

FIGURE 9-253  Unusual configuration of the epipericardial fat pad, showing increasing size over a 1-year period of growing obesity.

FIGURE 9-254  Lucency under the heart produced by the pressure of epipericardial fat.

FIGURE 9-255  Normal but prominent azygos arch in a young adult. One can distinguish this structure from an enlarged azygos node by noting the difference in its size between the supine and upright positions. (Ref: Keats TE, et al: Mensuration of the arch of the azygos vein and its application to the study of cardiovascular disease. Radiology 90:990, 1968.)



The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

889

FIGURE 9-256  Marked dilatation of the arch of the azygos vein in congenital interruption of the inferior vena cava. Absence of a shadow of the inferior vena cava in the lateral projection has been described. However, this sign is not always useful in diagnosis, because it may not be seen in some normal individuals. (Ref: Heller R, et al: A useful sign in recognition of azygos continuation of the inferior vena cava. Radiology 101:519, 1971.)

A

B FIGURE 9-257  A, B, Huge epipericardial fat pad on the right.

890

The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

FIGURE 9-258  Shadow of the left subclavian artery in a 75-year-old man (m). The edge of the manubrium is seen on the opposite side (m 66).

FIGURE 9-259  Marked calcification in the great vessels.

FIGURE 9-260  Marked calcification of the carotid, subclavian, and axillary arteries.



The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

FIGURE 9-261  Marked calcification of the subclavian arteries.

FIGURE 9-262  Mass effect produced by dilated brachiocephalic vessels (m 6 ) and arm shadow (m).

A

B

FIGURE 9-263  A, Broadened mediastinal outline on the left is caused by a very large left subclavian artery (m). An azygos lobe is also present (m 6). B, CT scan shows the large artery.

891

892

The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

FIGURE 9-264  Three examples of the aortic nipple. This normal shadow, which is caused by the highest intercostal vein, is seen in children and adults. (Ref: Ball JB Jr, Proto AV: The variable appearance of the left superior intercostal vein. Radiology 144:445, 1982.) The nipple should not exceed 4.5 mm in diameter. (Ref: Friedman AC, et al: The normal and abnormal left superior intercostal vein. AJR Am J Roentgenol 131:599, 1978.)

FIGURE 9-265  Three examples of the ductus bump in neonates. This density is seen in normal infants in the first day of life and usually disappears by the third day. A reflection of neonatal adjustment to extrauterine life, it is the shadow of the ductus functioning briefly before closure. (Ref: Berdon WE, et al: The ductus bump: A transient physiologic mass in chest roentgenograms of newborn infants. Am J Roentgenol Radium Ther Nucl Med 95:91, 1965.)

FIGURE 9-266  Infundibulum of the ductus, the point of insertion of the ductus in early life. Its presence does not indicate patency of the ductus. (Ref: Keats TE, Steinbach HL: Patent ductus arteriosus: A critical evaluation of its roentgen signs. Radiology 64:528, 1955.) The infundibulum may produce a figure-of-three shape, as illustrated in this case, that should not be misinterpreted as evidence of coarctation of the aorta or of aortic rupture. (Refs: Yousefzadeh DK, et al: The aortic isthmus. Radiology 140:701, 1981; Morse SS, et al: Traumatic aortic rupture: False-positive aortographic diagnosis due to atypical ductus diverticulum. AJR Am J Roentgenol 150:793, 1988.)



The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

893

FIGURE 9-267  Calcification in the ligamentum arteriosum.

A

B

C

D

FIGURE 9-268  Four examples of normal variation in the size of the pulmonary artery in children and young adults. The pulmonary artery is extremely variable in size, and its prominence in the young is a common finding. It should not be a source of concern in itself. A, A 5-year-old boy. B, An 8-year-old boy. C, A 9-year-old girl. D, An 18-year-old boy.

894

The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

FIGURE 9-269  Right aortic arch (m) with retroesophageal course is not necessarily associated with congenital heart disease and may be mistaken for a mediastinal mass. It displaces the esophagus to the left and anteriorly (m 6 ).

A

B

FIGURE 9-270  A, Tortuous aorta presenting on the right heart border (m). B, Lateral projection shows tortuosity.



The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

A

895

B

FIGURE 9-271  A, Widened mediastinum in this acutely injured patient is caused by filming in expiration and was misinterpreted as evidence of aortic rupture. B, Inspiratory film made within an hour of A shows a normal appearance.

A

B

FIGURE 9-272  Normal widening of the mediastinal silhouette in the supine position. This finding coupled with buckling of the trachea to the right in expiration (m) may lead to an erroneous diagnosis of traumatic rupture of the aorta. A, Upright film. B, Supine film.

896

The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

FIGURE 9-273  Lateral displacement of the superior vena cava by an ectatic aortic arch. (Ref: Drasin E, et al: Nondilated superior vena cava presenting as a superior mediastinal mass. J Can Assoc Radiol 23:273, 1972.)

FIGURE 9-274  Three examples of left superior vena cava.



The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

897

A

B

C

FIGURE 9-275  Idiopathic dilatation of the superior vena cava is a developmental variant of no significance. A, Plain film. B, Tomogram. C, Angiocardiogram. (Ref: Polansky S, et al: Idiopathic dilatation of the superior vena cava [IDSVC]. Pediatr Radiol 2:167, 1974.)

898

The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

FIGURE 9-276  Another example of idiopathic dilatation of the superior vena cava. Note similarity to Figure 9-275.

FIGURE 9-277  Prominent but normal shadow of the inferior vena cava.



The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

899

B

A FIGURE 9-278  The inferior vena cava may be seen above the diaphragm and adjacent to the right side of the heart border. A, PA projection. B, CT scan.

FIGURE 9-279  The inferior vena cava may be seen through the shadow of the right atrium.

900

The Soft Tissues of the Thorax  |  THE HEART AND GREAT VESSELS

FIGURE 9-280  Idiopathic dilatation of the inferior vena cava, so-called varix of the inferior vena cava, a finding of no clinical significance in itself. (Ref: Oh KS, et al: Inferior vena cava varix. Radiology 109:161, 1973.)

FIGURE 9-281  Three examples of confusing radiolucencies produced by the inferior vena cava. With maximum inspiration, it is possible to clear a portion of the diaphragmatic surface of the heart and expose the anterior wall of the inferior vena cava (m). This clearing results in a triangular area of radiolucency (m 6 ), which may be confusing if its origin is not appreciated. (Ref: Tonkin IL, et al: Radiographic isolation of the inferior vena cava. AJR Am J Roentgenol 129:657, 1977.)



The Soft Tissues of the Thorax  |  THE THYMUS

901

FIGURE 9-282  Shadow of the inferior vena cava simulating atelectasis. The upper margin is probably produced by superimposition of the heart shadow.

THE THYMUS

A

B

FIGURE 9-283  Variations in the configuration of the thymus. A, At birth, an appearance of the thymus simulating pneumomediastinum. B, Same individual at 16 months of age. The thymus is still prominent but is more closely applied to the mediastinum.

902

The Soft Tissues of the Thorax  |  THE THYMUS

FIGURE 9-284  Three examples of unilateral presentation of the thymus to the right side.

FIGURE 9-285  Two examples of the thymic “wave” sign. The undulating configuration of the edge of the thymus is caused by impression of the anterior portion of the ribs. (Ref: Mulvey RB: The thymic “wave” sign. Radiology 81:834, 1963.)



The Soft Tissues of the Thorax  |  THE THYMUS

FIGURE 9-286  Two examples of large left lobes of the thymus whose appearance suggests dextrocardia.

FIGURE 9-287  Two examples of a very large thymus simulating cardiomegaly.

FIGURE 9-288  Unilateral presentation of the thymus to the right and extending almost to the diaphragm.

FIGURE 9-289  Huge thymus in a 9-month-old baby.

903

904

The Soft Tissues of the Thorax  |  THE THYMUS

FIGURE 9-290  Huge thymus simulating cardiomegaly in the frontal plane. Note the radiolucency on the right, in contrast to the heart on the left.

B

A

C

D

FIGURE 9-291  A, Large thymus simulating cardiomegaly. B, Lateral projection fails to show corresponding cardiomegaly and indicates the large thymic outline anteriorly. Dextroangiocardiogram (C) and levoangiocardiogram (D) show normal cardiac size within the huge thymus.



The Soft Tissues of the Thorax  |  THE THYMUS

FIGURE 9-292  Left lobe of the thymus simulating enlargement of the left atrial appendage.

FIGURE 9-293  Unilateral “sail” configuration of the right lobe of the thymus.

FIGURE 9-294  Extension of the thymus to the apex of the right atrium.

905

906

The Soft Tissues of the Thorax  |  THE THYMUS

FIGURE 9-295  Unusual configuration of the thymus. Note the large shadow of the thymus in the lateral projection.

FIGURE 9-296  Unusually rounded configuration of the thymus.

FIGURE 9-297  Two examples in which the thymus resembles the “snowman heart” of total anomalous pulmonary venous return.



The Soft Tissues of the Thorax  |  THE THYMUS

907

FIGURE 9-298  Examples of the thymus presenting entirely to the right side.

FIGURE 9-299  Thymus in a neonate producing a relative radiolucency anteriorly in the lateral projection, which was originally mistaken for a hernia through Morgagni’s foramen.

FIGURE 9-300  Right lobe of the thymus simulating right upper lobe pneumonitis. The thymus may simulate upper lobe atelectasis as well. (Ref: Lanning P, Heikkinen E: Thymus simulating left upper lobe atelectasis. Pediatr Radiol 9:177, 1980.)

908

The Soft Tissues of the Thorax  |  THE THYMUS

FIGURE 9-301  Large thymus misdiagnosed as right upper lobe pneumonia because of its appearance in the lateral projection.

FIGURE 9-302  Absence of visible thymus on the right simulates dextrocardia.

FIGURE 9-303  Posterior mediastinal thymus, a rare variant. At surgery the thymus was found to be connected to the anterior mediastinum by a thin pedicle. (Refs: Cohen MD, et al: The diagnostic dilemma of the posterior mediastinal thymus: CT manifestations. Radiology 146:691, 1983; Bar-Ziv J, et al: Posterior mediastinal accessory thymus. Pediatr Radiol, 14:165, 1984; Siegel MJ, et al: Normal and abnormal thymus in childhood: MR imaging. Radiology 172:367, 1989.)



The Soft Tissues of the Thorax  |  THE THYMUS

909

FIGURE 9-304  The thymus does not always regress in early childhood and may persist into early adolescence. Its presence in late childhood, therefore, should not be construed as evidence of abnormality. Note the residual thymus in a 14-year-old boy. (Ref: Oh KS, et al: Normal mediastinal mass in late childhood. Radiology 101:625, 1971.)

A

B FIGURE 9-305  Late persistence of the thymus. A, A 1-year-old child. B, A 9-year-old child.

910

The Soft Tissues of the Thorax  |  THE THYMUS

FIGURE 9-306  Residual thymus in a 6-year-old girl.

FIGURE 9-307  Residual thymus in a 6-year-old boy.



The Soft Tissues of the Thorax  |  THE THYMUS

A

911

B FIGURE 9-308  A, Residual thymus in an 8-year-old girl. B, A 2-year follow-up film.

FIGURE 9-309  Residual thymus in a 9-year-old boy.

FIGURE 9-310  Residual thymus in a 9-year-old boy, which can be traced across the mediastinum.

912

The Soft Tissues of the Thorax  |  THE THYMUS

B A

C FIGURE 9-311  A, Residual thymus in an 11-year-old boy. B, C, Frontal and left anterior oblique projections in a 14-year-old boy showing residual thymus.



The Soft Tissues of the Thorax  |  THE THYMUS

FIGURE 9-313  Residual thymus in a 13-year-old girl.

FIGURE 9-312  Large residual thymus in a 15-year-old boy.

FIGURE 9-314  Residual thymus in a 19-year-old woman.

913

CHAPTER

10

The Diaphragm PAGES 914 to 921

FIGURES THE DIAPHRAGM

10-1 to 10-18

THE DIAPHRAGM

FIGURE 10-1  Sternal insertions of the diaphragm, which consist of a pair of short, narrow slips that arise from the back of the xiphoid and pass backward to be inserted into the central tendon of the diaphragm. (Ref: Kleinman PK, Raptopoulos V: The anterior diaphragmatic attachments: An anatomic and radiologic study with clinical correlates. Radiology 155:289, 1985.)

914



The Diaphragm  |  THE DIAPHRAGM

915

FIGURE 10-2  “Scalloping” of the diaphragm is caused by hypertrophy and contraction of individual muscle bundles in the diaphragm. These films show multiple small convexities.

FIGURE 10-3  “Scalloping” of the diaphragm, with several large convexities.

FIGURE 10-4  “Scalloping” of the diaphragm.

916

The Diaphragm  |  THE DIAPHRAGM

FIGURE 10-5  Additional variations of “scalloped” diaphragms.

FIGURE 10-6  Crus of the left hemidiaphragm.

A

B

FIGURE 10-7  High insertions of the medial attachments of the diaphragm simulating mass lesions. A, Inspiration. B, Partial expiration, in which the attachments are not seen as clearly.



The Diaphragm  |  THE DIAPHRAGM

917

FIGURE 10-8  Muscular slips of the diaphragm seen in maximal inspiration.

FIGURE 10-9  Localized eventration of the diaphragm in a child. Without benefit of the lateral projection, this variation could be mistaken for a mass lesion.

918

The Diaphragm  |  THE DIAPHRAGM

FIGURE 10-10  Intrathoracic migration of the right kidney through the right foramen of Bochdalek in a 70-year-old woman that was not present on an examination made 20 years earlier. Diaphragmatic defects and pseudolesions such as fat and visceral herniations through diaphragmatic defects increase in number and severity in the seventh and eighth decades of life.

FIGURE 10-11  Another example of the entity illustrated in Figure 10-10, seen here on the left.



The Diaphragm  |  THE DIAPHRAGM

919

FIGURE 10-12  Intrathoracic migration of the colon through the foramen of Bochdalek in an 83-year-old woman.

FIGURE 10-13  Intrathoracic migration of the kidney through the foramen of Bochdalek is not seen on shallow inspiration (left) but is visualized with maximal inspiration (right).

920

The Diaphragm  |  THE DIAPHRAGM

FIGURE 10-14  Bilateral anterior diaphragmatic eventration in a newborn. This condition may be asymptomatic. Note the upward displacement of the heart. (Ref: Avnet NE: Roentgenologic features of congenital bilateral interior diaphragmatic eventration. Am J Roentgenol Radium Ther Nucl Med 88:743, 1962.)

FIGURE 10-15  Increased distance between the stomach gas bubble and the diaphragm suggests a subpulmonic effusion. The lateral projection indicates that this appearance is caused by the fact that the posterior portion of the left hemidiaphragm (9) is higher than the anterior portion (m 6 ), which is adjacent to the gas bubble.

FIGURE 10-16  Unusual left lobe of the liver which interposes between the stomach and left diaphragm and may simulate a basal pleural effusion.



The Diaphragm  |  THE DIAPHRAGM

921

FIGURE 10-17  Increased distance between the stomach gas bubble and the diaphragm in lateral projection caused by the medial position of the gas bubble (9) in relation to the highest point of the dome of the diaphragm (m 6 ).

FIGURE 10-18  Increased distance between the stomach gas bubble and the diaphragm in lateral projection caused by the impression of the heart on the gas bubble (9).

CHAPTER

11

The Soft Tissues of the Abdomen PAGES

FIGURES

923 to 942

THE ABDOMEN IN GENERAL

11-1 to 11-58

943 to 1005 943 to 948 949 to 965 966 to 973 973 to 978 979 to 999 1000 to 1005

THE GASTROINTESTINAL TRACT The Esophagus The Stomach The Duodenum The Small Intestine The Colon The Liver and Biliary Tract

11-59 to 11-210 11-59 to 11-73 11-74 to 11-115 11-116 to 11-137 11-138 to 11-151 11-152 to 11-194 11-195 to 11-210

922



The Soft Tissues of the Abdomen  |  THE ABDOMEN IN GENERAL

923

THE ABDOMEN IN GENERAL

FIGURE 11-2  Posterior skin folds lend a striking appearance to the abdomen in an elderly patient.

FIGURE 11-1  Skin folds producing an unusual appearance of the hepatic shadow in an infant.

A

B

FIGURE 11-3  A, Simulated lucency of the psoas muscles produced by folding of the soft tissues of the back. B, This appearance is not seen in the subsequent film after alteration of the patient’s position.

924

The Soft Tissues of the Abdomen  |  THE ABDOMEN IN GENERAL

FIGURE 11-4  Lucent stripes in the shadow of the psoas muscle caused by fat between the muscle bundles.

FIGURE 11-5  Skin fold simulating a lucent psoas muscle shadow.

B

A FIGURE 11-6  A, Good visualization of the right psoas muscle shadow but not of the left. B, CT scan shows a large right psoas muscle and a smaller left muscle. Such nonvisualization may also be caused by the obliquity of the muscle itself. (Ref: Williams SM, et al: Psoas sign: Reevaluation. Radiographics 5:525, 1985.)



The Soft Tissues of the Abdomen  |  THE ABDOMEN IN GENERAL

925

FIGURE 11-7  Simulated mass in the right flank produced by muscle splinting on that side.

FIGURE 11-8  Two examples of simulated pneumoperitoneum caused by the Mach effect of the rib superimposed on the diaphragm.

FIGURE 11-9  Simulated pneumoperitoneum caused by subdiaphragmatic fat. (Ref: Rao KG, Woodlief RM: Excessive right subdiaphragmatic fat: A potential diagnostic pitfall. Radiology 138:15, 1981.)

926

The Soft Tissues of the Abdomen  |  THE ABDOMEN IN GENERAL

A

B

C FIGURE 11-10  Simulated pneumoperitoneum produced by subdiaphragmatic fat. A, B, Frontal films obtained on two different days. C, Lateral projection.

FIGURE 11-11  Fat may also be seen beneath the left hemidiaphragm, as illustrated in these two patients.



The Soft Tissues of the Abdomen  |  THE ABDOMEN IN GENERAL

927

FIGURE 11-12  Left, Fat between the fundus of the stomach and the diaphragm. Right, Lateral projection shows fat located anteriorly, beneath the diaphragm.

FIGURE 11-14  Simulated pneumoperitoneum produced by fat between the junction of the stomach and the diaphragm.

FIGURE 11-13  Simulated pneumoperitoneum produced by fat between the fundus of the stomach and the diaphragm. Top, Two air-fluid levels are seen in the upright frontal film. Plain arrow (m) indicates fat; hatched arrow (m 6) indicates stomach. Bottom, Lateral projection shows the anterior position of the stomach with a large air-fluid level (m 6 ) and fat interposed between the stomach and the diaphragm (m). Note how far anteriorly the normal stomach may extend.

FIGURE 11-15  Simulated pneumoperitoneum produced by lucent interval between the two diaphragmatic shadows and an air-filled stomach.

928

The Soft Tissues of the Abdomen  |  THE ABDOMEN IN GENERAL

FIGURE 11-16  Simulated pneumoperitoneum on the left produced by superimposition of the colon (m) on the stomach (m 6 ).

A

B

C

D FIGURE 11-17  A, B, Simulated pneumoperitoneum with an air-fluid level (m) that appeared to be distant from the stomach air bubble (m 6 ). C, D, The problem is clarified by inflation of the stomach with more air, indicating that both gas collections are in the stomach. The apparent separation in B is the result of the two diaphragmatic contours, as shown in D (m 66).



The Soft Tissues of the Abdomen  |  THE ABDOMEN IN GENERAL

929

FIGURE 11-19  Air beneath the breasts simulating pneumoperitoneum.

FIGURE 11-18  Simulated air-fluid level beneath the right hemidiaphragm resulting from through-projection of the different heights of the base of the diaphragm (m) and its dome (m 6).

FIGURE 11-20  Simulated pneumoperitoneum produced by fat around the lateral and superior aspects of the liver. The right side of the liver may also be visualized by ascites. (Ref: Proto AV, Lane EJ: Visualization of differences in soft-tissue densities: The liver in ascites. Radiology 121:19, 1976.)

The Soft Tissues of the Abdomen  |  THE ABDOMEN IN GENERAL

930

FIGURE 11-21  CT scan showing the fat around the liver that produces the radiolucency seen in Figure 11-20.

A

B FIGURE 11-22  The liver and spleen are demonstrated with unusual clarity (A) because of surrounding fat, as confirmed by CT scan (B).

FIGURE 11-23  Colonic interposition on the right simulating pneumoperitoneum.



The Soft Tissues of the Abdomen  |  THE ABDOMEN IN GENERAL

931

FIGURE 11-24  Colonic interposition simulating pneumoperitoneum in the frontal film, clarified on lateral film.

FIGURE 11-25  Colonic interposition between the liver and the diaphragm (m) and between the spleen and the diaphragm (m 66) in a 3-year-old child. This is a common finding in children and is not usually productive of symptoms. It should not be confused with pneumoperitoneum. (Ref: Behlke FM: Hepatodiaphragmatic interposition in children. Am J Roentgenol Radium Ther Nucl Med 91:669, 1964.)

A

B

FIGURE 11-26  Colonic interposition between the liver and diaphragm in a 4-year-old boy (A) and its spontaneous reduction on the same day (B).

932

The Soft Tissues of the Abdomen  |  THE ABDOMEN IN GENERAL

A

B FIGURE 11-27  Colonic interposition simulating a subphrenic abscess. A, Supine film. B, Upright film.

FIGURE 11-28  In the supine position, the fluid-filled fundus of the stomach simulates a mass lesion. Left, Plain film. Right, Tomogram. This pseudotumor may opacify on angiography, thus further obscuring its proper identification. (Ref: Bjorn-Hansen RW, O’Brien DS: Aortographic opacification of the gastric fundus simulating neoplasm. Am J Roentgenol Radium Ther Nucl Med 100:408, 1967.)



The Soft Tissues of the Abdomen  |  THE ABDOMEN IN GENERAL

A

933

B

C FIGURE 11-29  A, Fluid-filled duodenal bulb may manifest as a right upper quadrant mass in the prone position. B, Supine film shows the mass less distinctly. C, Barium examination shows the mass effect to be caused by the duodenal bulb.

A

B

FIGURE 11-30  A, In the prone position, the fluid-filled gastric antrum may also simulate a right upper quadrant mass. B, Antrum filled with barium in same position as A. (Ref: Balthazar E: Right upper quadrant pseudotumor, a fluid-filled viscus. Radiology 112:11, 1974.)

934

The Soft Tissues of the Abdomen  |  THE ABDOMEN IN GENERAL

FIGURE 11-31  Gas-filled gastric fundus displacing the shadow of the spleen (m) from the diaphragm, simulating a mass.

FIGURE 11-32  Left lobe of the liver encroaching on the stomach gas bubble, simulating a neoplasm (see Fig. 11-84).

FIGURE 11-33  Liver shadow encroaching on the stomach gas bubble in both projections.



The Soft Tissues of the Abdomen  |  THE ABDOMEN IN GENERAL

FIGURE 11-34  Fluid-filled antrum of the stomach with the lucent folds of the pylorus simulating a gallstone with fissures within it.

FIGURE 11-35  The antrum and pylorus superimposed.

935

936

The Soft Tissues of the Abdomen  |  THE ABDOMEN IN GENERAL

B

A

FIGURE 11-36  Gas in the small bowel in the flank that can simulate colon or free air in the peritoneal cavity. A, Supine film. B, Left lateral decubitus film.

FIGURE 11-37  Fluid-filled splenic flexure of the colon simulating a mass encroaching on the stomach.

FIGURE 11-38  Posterior lung margins simulating an abdominal mass.



The Soft Tissues of the Abdomen  |  THE ABDOMEN IN GENERAL

FIGURE 11-39  Simulated properitoneal fat line produced by the contact of the patient’s arm with the abdomen (m). A true properitoneal fat line is seen on the opposite side (m 66).

FIGURE 11-41  Riedel’s lobe of the liver, which may be mistaken for a right lower quadrant mass.

937

FIGURE 11-40  Fat around the ligamentum teres of the liver produces a bilobed appearance of the liver or simulates a mass. (Ref: Haswell DM, et al: Plain film recognition of the ligamentum teres hepatis. Radiology 114:263, 1975.)

FIGURE 11-42  Riedel’s lobe of the liver (m) and perinephric fat (m 6) produce an appearance suggesting gas in the perirenal space.

938

The Soft Tissues of the Abdomen  |  THE ABDOMEN IN GENERAL

FIGURE 11-43  Two examples of the “double wall” sign. The ability to see both sides of the bowel wall is not reliable evidence of pneumoperitoneum. In these cases, it is caused by two loops of distended intestine in contact with each other. (Ref: de Lacy G, et al: Pneumoperitoneum: The misleading double wall sign. Clin Radiol 28:445, 1977.)

FIGURE 11-44  Extensive mesenteric fat simulating pneumoperitoneum.

FIGURE 11-45  Air in the appendix is a normal phenomenon and should not be considered as evidence of acute appendicitis. (Ref: Shaffer HA Jr, Harrison GB: Gas in the appendix: A sometime significant but non-specific diagnostic sign. Arch Surg 114:587, 1979.) Gas may also be seen in the appendix with a subhepatic cecum. (Ref: Hussain SM, Ginal AZ: Case of the month: All’s well that ends well (with apology to W Shakespeare). Brit J Radiol 68:435, 1995.)



The Soft Tissues of the Abdomen  |  THE ABDOMEN IN GENERAL

939

FIGURE 11-47  Gastric contents simulating the changes of bronchiectasis at the base of the left lung.

FIGURE 11-46  Shadow of the umbilicus seen in the oblique projection of the abdomen.

FIGURE 11-49  Ring-shaped calcified costal cartilage simulating gallstones.

FIGURE 11-48  Visualization of the diaphragmatic attachments.

940

The Soft Tissues of the Abdomen  |  THE ABDOMEN IN GENERAL

FIGURE 11-50  Calcified costal cartilage in the left upper quadrant simulating a renal calculus. FIGURE 11-51  Calcification in a tortuous splenic artery.

FIGURE 11-53  Enteroliths in the cecum formed around ingested prune pits.

FIGURE 11-52  Ingested seeds in the transverse colon simulating pancreatic calcification.



The Soft Tissues of the Abdomen  |  THE ABDOMEN IN GENERAL

FIGURE 11-54  Ossification center of the last coccygeal segment in a 10-year-old boy, which should not be mistaken for a calculus.

A

B

C

FIGURE 11-55  Calcified epiploic appendage still attached to colon. A, Frontal film. B, Oblique projection. C, Same entity in another patient.

941

942

The Soft Tissues of the Abdomen  |  THE ABDOMEN IN GENERAL

FIGURE 11-56  Calcified epiploic appendage. Such appendages have a characteristic oval shape with a more lucent center.

FIGURE 11-57  Dystrophic calcification in obliterated umbilical arteries in a 2-year-old child, an unusual normal finding in infants. (From Currarino G, Weinberg A: Dystrophic calcification in obliterated umbilical artery. Pediatr Radiol 15:346, 1985.)

FIGURE 11-58  Edge of the sacroiliac joint simulating calcification in the appendix. The appearance is less marked on the opposite side.



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

THE GASTROINTESTINAL TRACT The Esophagus

FIGURE 11-59  Lingual tonsil, which consists of a fine fibrous network containing lymphoid tissue scattered over the pharyngeal part of the tongue. (Ref: Gromet NL, et al: Lymphoid hyperplasia in the base of the tongue: Spectrum of a benign entity. Radiology 144:825, 1982.)

FIGURE 11-60  Pseudomass of the pharynx produced by the larynx and barium in the pyriform sinuses during the early phase of swallowing. (Ref: Howie JL: Postcricoid pseudotumor. J Can Assoc Radiol 31:225, 1980.) FIGURE 11-61  Impression of the cricopharyngeus muscle.

943

944

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

FIGURE 11-62  Four examples of the variable appearance of the postcricoid impression, which is caused by the prolapse of lax mucosal folds over the ventral submucosal venous plexus (m). It is not seen after the barium bolus is passed. (Ref: Pitman RG, Frazer GM: The postcricoid impression on the esophagus. Clin Radiol 16:34, 1965.)

FIGURE 11-63  Marked shift of the esophagus to the left at the thoracic inlet caused by narrowness of the bony inlet. This variation is often mistaken for displacement caused by a mass lesion. (Ref: Kendall BE, et al: A physiologic variation in the barium-filled gullet. Br J Radiol 35:769, 1962.)



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

945

FIGURE 11-64  Upright double-contrast esophagram shows smooth extrinsic impression on the posterolateral wall of the upper esophagus produced by the prominent right inferior supra azygous recess. (Ref: Sam JW, et al: The right inferior supraazygous recess: A cause of upper esophageal pseudomass on double-contrast esophagography. AJR Am J Roentgenol 171:1583, 1998.)

FIGURE 11-65  Pulmonary venous indentation on the esophagus caused by pressure of the inferior pulmonary vein, a normal variant. The asterisk indicates the venous impression; the arrow marks the aortic arch. (From Yeh H, Wolf BS: A pulmonary venous indentation on the esophagus: A normal variant. Radiology 116:299, 1975.)

FIGURE 11-66  Visualization of the esophageal walls in a postlaryngectomy patient with esophageal speech.

946

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

FIGURE 11-68  Illustration of the great normal distensibility of the infantile esophagus, which might be mistaken for megaesophagus.

FIGURE 11-67  Presbyesophagus. Tertiary contractions (“curling”) of the esophagus, frequently found in the elderly, are not usually of significance. (Ref: Zboralske FF, et al: Presbyesophagus: Cineradiographic manifestations. Radiology 82:463, 1964.)

FIGURE 11-69  Transverse striations of the esophagus may be seen as a normal variation and in pathologic states, particularly in association with gastroesophageal reflux. (Refs: Gohel VK, et al: Transverse folds in the human esophagus. Radiology 128:303, 1978; Williams SM, et al: Transverse striations of the esophagus: Association with gastroesophageal reflux. Radiology 146:25, 1983.)



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

A

947

B

FIGURE 11-70  A, B, Transverse striations seen in A are transient, as illustrated in these two films made with the same barium swallow.

A

B

C

FIGURE 11-71  Focal spiculation of the upper thoracic esophagus, a normal variant. This entity is seen above the level of the aortic arch and should not be mistaken for a focal area of esophagitis. A, Spiculation at edge of peristaltic wave. B, Spiculation seen in another patient. C, View of same patient as in B, obtained moments later with greater distention, shows normal appearance. (From Levine MS, et al: Focal spiculation of the upper thoracic esophagus: Normal variant at double-contrast esophagography. Radiology 183:807, 1992.)

948

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

A

B

C

FIGURE 11-72  Impression of the left main bronchus on the esophagus. A, Full column. B, C, Partial column.

A

C

B

D

FIGURE 11-73  A, B, Esophageal impression of an aberrant right subclavian artery. C, D, Angiocardiogram shows anomalous origin of the right subclavian artery from the proximal descending aorta. (Ref: Freed K, Low VH: The aberrant subclavian artery. AJR Am J Roentgenol 168:481, 1997.)



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

949

The Stomach

A

B FIGURE 11-74  Proportional differences in size between the stomach and total abdomen in an infant (A) and an adult (B). The infant’s stomach is proportionately larger, an important concept in avoiding misinterpretation of the size of the air-distended stomach in an infant. (From Keats TE: Pediatric radiology: Some potentially misleading variations from the adult. Va Med Mon 93:630, 1966.)

FIGURE 11-75  Normal but marked gaseous distention of the stomach in crying infants.

950

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

FIGURE 11-76  Normal but marked gaseous distention of the stomach in a crying infant.

FIGURE 11-77  Two examples of the cardioesophageal junction seen en face, which may simulate a polypoid filling defect in the stomach.



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

FIGURE 11-78  Esophagogastric junction presenting as a polypoid filling defect.

A

951

FIGURE 11-79  Invagination of the esophageal mucosa at the cardia simulating a mass lesion. (Ref: de Lorimier AA, Warren JP: Prolapse of the mucosa at the esophagogastric junction. Am J Roentgenol Radium Ther Nucl Med 84:1061, 1960.)

B

FIGURE 11-80  Esophageal mucosa simulating a gastric mass in a patient with a hiatal hernia. A, Mucosa is prolapsed into the stomach. B, Hernia is now present and prolapse is no longer evident. (Ref: Aldridge NH: Transmigration of the lower esophageal mucosa. Radiology 79:962, 1962.)

952

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

FIGURE 11-81  Gastric diverticulum in its typical location in the cardia of the stomach.

FIGURE 11-82  Prolapse of the esophageal mucosa into the stomach (proven at surgery).



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

FIGURE 11-83  Two examples of developmental gastric diverticula in their classic position.

FIGURE 11-84  Left lobe of the liver encroaching on the stomach gas bubble (proven at surgery), simulating a neoplasm (see Fig. 11-32).

FIGURE 11-85  Gastric impressions related to the left lobe of the liver.

953

954

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

FIGURE 11-86  Spleen encroaching on the stomach gas bubble.

FIGURE 11-87  Impression of a horizontally oriented spleen simulating a gastric mass.

A

B FIGURE 11-88  Splenic impression on the fundus of the stomach. A, Gastrointestinal contrast (GI) series. B, CT scan confirmation.



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

A

955

B

FIGURE 11-89  Impression of a normal spleen on the stomach. A, AP projection. B, Left posterior oblique projection. C, CT scan shows the anterior tip of the spleen projecting into the stomach gas bubble.

C

FIGURE 11-90  Impression of the costal margin on the stomach, simulating a mass lesion. A, Partially filled stomach. B, Completely filled stomach (the impression is not as well seen here).

A

B

956

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

A

B

FIGURE 11-91  Normal impressions of the pancreas on the posterior wall of the stomach in an 8-year-old girl. A, Supine lateral projection. B, Upright lateral projection.

FIGURE 11-92  Additional examples of the impression of the costal margin simulating a mass lesion.



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

A

B

FIGURE 11-93  Barium in the minute folds of the gastric mucosa (confirmed by gastroscopic examination) simulating small ulcers. This entity may also be seen in the colon. A, Conventional film. B, Enlargement. (Ref: Stone DD, Keats TE: Anatomical and physiological characteristics of the etat Mammelonne, a normal variant of the gastric mucosa. Radiology 107:537, 1973.)

FIGURE 11-94  Normal appearance of the areae gastricae.

957

958

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

FIGURE 11-95  Normal gastric mucosal pattern of the stomach on double-contrast examination.

FIGURE 11-96  Air bubbles in the stomach simulating polypoid lesions.

FIGURE 11-97  Two examples of artifactual gastric erosions produced by particles of barium. Note the absence of surrounding halos. (Refs: Gohel VK, et al: Double contrast artifacts. Gastrointest Radiol 3:139, 1978; Aronchick J et al: Barium stalactites: Observations on their nature and significance. Radiology 149:588, 1983; Samuel E: Radiology of normal and abnormal gastric mucus. Br J Radiol 60:987, 1987.)



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

959

FIGURE 11-98  Compression films of the stomach producing “kissing” artifacts that simulate mass lesions.

FIGURE 11-99  Barium drip simulating a gastric diverticulum. (Ref: Shackelford GD: Barium collections in the stomach mimicking intramural diverticula. AJR Am J Roentgenol 139:805, 1982.)

FIGURE 11-100  Normal transverse mucosal folds of the stomach. (Ref: Cho KC, et al: Multiple transverse folds in the gastric antrum. Radiology 164:339, 1987.)

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

960

A

B

C

FIGURE 11-101  Pseudoulceration of the antrum, produced by peristaltic waves seen in A and B but not in C.

FIGURE 11-102  Pseudoulceration of the lesser curve of the antrum produced by peristaltic waves. (Ref: Peavy PW, et al: Gastric pseudo-ulcers: Membrana angularis and pyloric torus defects. Radiology 114:591, 1975.)



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

961

A

FIGURE 11-104  Well-defined muscle band in the body of the stomach.

B FIGURE 11-103  Additional example of pseudoulceration of the antrum, seen in A but not in B. (Ref: Bremner CG: The lesser curve pyloric niche. Br J Radiol 41:291, 1968.)

FIGURE 11-105  Functional and transient peristaltic events of the gastric antrum should not be mistaken for mucosal diaphragms. (Ref: Ghahremani GG: Nonobstructive mucosal diaphragms or rings of the gastric antrum in adults. Am J Roentgenol 121:236, 1974.)

962

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

FIGURE 11-106  Additional examples of simulated antral diaphragms. This entity may be particularly confusing in infants. (Ref: Fujioka M, et al: Pseudoweb of the gastric antrum in infants. Pediatr Radiol 9:73, 1980.)

FIGURE 11-107  Partial gastric diverticulum that could be mistaken for a penetrating ulcer. (Ref: Treichel J, et al: Diagnosis of partial gastric diverticula. Radiology 119:13, 1976.)

FIGURE 11-108  Another example of a partial gastric diverticulum.



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

963

FIGURE 11-109  Additional example of a partial gastric diverticulum.

A

B

FIGURE 11-110  A, Transient antral spasm may simulate hypertrophic pyloric stenosis. B, Film made later in same session shows an absence of antral narrowing.

964

A

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

B

FIGURE 11-111  A, Impression on greater curvature of the stomach that simulates pancreatic enlargement. B, The impression on the stomach is produced by the filled colon.

FIGURE 11-112  Left, Aberrant pancreas in the antrum. Right, Aberrant pancreas in the same position showing branching ductal pattern. (From Stone DD, et al: An unusual case of aberrant pancreas in the stomach: A roentgenographic and gastrophotographic demonstration. Am J Roentgenol Radium Ther Nucl Med 113:125, 1971.)



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

965

FIGURE 11-113  Pyloric canal seen en face, simulating an ulcer.

FIGURE 11-115  “Pyloric star” seen through the fluid-filled antrum (see Figs. 11-114 and 11-115).

FIGURE 11-114  Additional example of the pyloric canal (“pyloric star”) seen on end, simulating an ulcer.

966

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

The Duodenum

FIGURE 11-116  Air-filled duodenal bulb projected on the gastric antrum, simulating a polyp. Also note the air bubbles in the stomach, which might be mistaken for polyps.

FIGURE 11-117  Prolapse of the antral mucosa into the base of the duodenal bulb. This entity is not usually of clinical significance. FIGURE 11-118  Food (spaghetti) in the duodenal bulb simulating an ascaris.

FIGURE 11-119  Brunner’s gland hypertrophy may be seen in dyspeptic patients and in asymptomatic individuals and should not be mistaken for polyps. (Ref: Fraser GM, et al: Coarse duodenal mucosal folds in patients with dyspepsia and a high gastric acid output. Clin Radiol 22:78, 1971.)



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

967

FIGURE 11-121  Heterotopic pancreatic rest in the duodenal bulb.

FIGURE 11-120  Aberrant pancreatic rest in the base of the duodenal bulb.

FIGURE 11-122  Two examples of inversion of the duodenum (duodenum inversum), a clinically unimportant variation in the course of the duodenal loop that does not connote malrotation. (Ref: Faegenburg O, Bosniak M: Duodenal anomalies in the adult. Am J Roentgenol Radium Ther Nucl Med 88:642, 1962.)

968

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

FIGURE 11-123  Spot films to show normal but prominent mucosal folds of the duodenal bulb. Note the pliability and changing pattern.

A

FIGURE 11-124  Lumen of the second portion of the duodenum seen en face, simulating an intraluminal lesion.

B

FIGURE 11-125  A, Lumen of the second portion of the duodenum seen on end, simulating a filling defect. B, The pseudolesion is not seen on the subsequent film.

A

B

FIGURE 11-126  A, Air bubbles in the duodenal bulb simulating polypoid filling defects. B, Normal appearance is seen on repeat examination.



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

969

FIGURE 11-127  Two examples of circular mucosal filling defects said to be caused by ectopic gastric mucosa. (Ref: Smithuis RH, Vos CG: Heterotopic gastric mucosa in the duodenal bulb: Relationship to peptic ulcer. AJR Am J Roentgenol 152:59, 1989.) Benign lymphoid hyperplasia may also produce similar filling defects. (Ref: Govoni AF: Benign lymphoid hyperplasia of the duodenal bulb. Gastrointest Radiol 1:267, 1976.)

A

B

FIGURE 11-128  A, Simulated “bull’s-eye” lesion in the duodenum that was originally diagnosed as a metastatic deposit in a patient with melanoma. This appearance, produced by the lumen of the second portion of the duodenum, is not seen in B.

FIGURE 11-129  Other examples of air bubbles in the duodenal bulb simulating filling defects.

970

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

FIGURE 11-130  Simulated ulcer at the apex of the bulb produced by peristaltic contraction. (Ref: Burrell M, Toffler R: Flexural pseudolesions of the duodenum. Radiology 120:313, 1976.)

FIGURE 11-131  Two examples of anomalous peritoneal folds of the duodenum. This fold results in a characteristic smooth, extrinsic indentation upon the anterosuperior surface of the duodenal bulb. (From Low VH, et al: Anomalous peritoneal folds of the duodenum: A normal variant simulating disease. Australas Radiol 36:135, 1992.)



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

971

FIGURE 11-132  Four examples of flexural pseudomasses or ulcers at the apex of the bulb caused by the prominence of the mucosal folds. (Ref: Nelson JA, et al: Duodenal pseudopolyp: The flexure fallacy. Am J Roentgenol Radium Ther Nucl Med 123:262, 1975.)

FIGURE 11-133  Impression of the common duct in a normal 18-year-old woman.

972

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

A

B

FIGURE 11-134  A, Impressions of the gallbladder on the superior aspect of the duodenum (m) and the antrum of the stomach (m 6). B, Cholecystogram shows position of the gallbladder in reference to the impressions in A. (Ref: Smeets R, Op den Orth JO: Gallbladder: Common cause of antral pad sign. AJR Am J Roentgenol 132:571, 1979.)

A

B FIGURE 11-135  Ampulla of Vater in normal subjects. A, A 2-week-old infant. B, An adult.

FIGURE 11-136  Apparent widening of the duodenal loop produced by high position of the transverse colon, which elevates the stomach and uncovers more of the duodenal loop than is normally seen.



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

973

FIGURE 11-137  Medial displacement of the second portion of the duodenum by the right kidney. (Ref: Yoong P, House R: Deceptive deformity. Br J Radiol 53:1012, 1980.)

The Small Intestine

FIGURE 11-138  Normal prominence of the pattern of the valvulae conniventes of the small bowel in a 2-year-old boy. FIGURE 11-139  Normal grouping of the proximal loops of the jejunum of the left midabdomen, not to be confused with an internal hernia.

974

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

FIGURE 11-140  Two examples of malrotation of the bowel with ramification of the proximal small bowel on the right rather than on the left.

FIGURE 11-141  Abnormal pattern of the duodenum and proximal small bowel caused by large amount of mucus in the stomach.



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

FIGURE 11-142  Three examples of unusual small bowel patterns in infants caused by mucus-impregnated barium.

975

976

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

A FIGURE 11-144  Normal mucosal pattern of the adult small bowel shown by double contrast examination.

B FIGURE 11-143  Normal prominent mucosal patterns of the small bowel of young children. A, A 2-year-old child. B, A 3-year-old child.

FIGURE 11-145  Areas of peristaltic contraction may be mistaken for ascariasis in children.

FIGURE 11-146  Unusual small bowel pattern resulting from a large amount of fat in the mesentery.



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

977

FIGURE 11-147  The “cobblestone” terminal ileum in a 3-year-old boy. This normal variation is caused by the large amounts of lymphoid tissue in this portion of the bowel and should not be mistaken for evidence of inflammatory bowel disease. (Ref: Lassrich MA: Nonspecific changes in the terminal ileum of children. Fortschr Roentgenstr 95:757, 1961.)

FIGURE 11-148  Normal lymphoid hyperplasia of the terminal ileum in a 16-year-old boy, a further reflection of the process illustrated in Figure 11-147. These changes are often misinterpreted as evidence of Crohn’s disease.

FIGURE 11-149  Lymphoid hyperplasia in the terminal ileum of a healthy 62-year-old man.

978

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

FIGURE 11-150  Mucosal folds in the terminal ileum simulating ascariasis.

A

B

FIGURE 11-151  A, Distended urinary bladder displacing the small bowel and colon in a young child. B, Disappearance of displacement after catheterization and removal of 300 mL of urine.



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

979

The Colon

A

B

FIGURE 11-152  Proportional difference in the size of the colon and the abdomen in a 3-year-old child (A) and an adult (B). The colon of the infant and that of the child occupy a proportionately larger area of the abdomen, and its size should not be mistaken for megacolon. (From Keats TE: Pediatric radiology: Some potentially misleading variations from the adult. Va Med Mon 93:630, 1966.)

FIGURE 11-154  Malrotation of the bowel. The colon lies entirely in the left side of the abdomen. Arrows indicate the ascending colon.

FIGURE 11-153  Illustration of the great distensibility of the normal juvenile colon, shown here in a 21/2-year-old child.

980

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

FIGURE 11-155  “Overrotation” of the colon, with an elongated ascending portion and the cecum presenting in the midabdomen (m).

A

B

FIGURE 11-156  A, B, Mobile cecum. Note the change of position after evacuation (B). Although not clinically significant in itself, such mobility predisposes to volvulus.



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

981

FIGURE 11-158  Displacement of the colon and small bowel by a distended urinary bladder in a 5-year-old boy. FIGURE 11-157  Subhepatic cecum (m) and appendix (m 66).

FIGURE 11-159  Lateral displacement of the right kidney by the colon. Left, Plain film tomogram from an intravenous urogram. Right, CT scan shows the lateral displacement of the kidney by the ascending colon. (From Silverman PM, et al: Lateral displacement of the right kidney by the colon: An anatomic variation demonstrated by CT. AJR Am J Roentgenol 140:313, 1983.)

982

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

A

B

C FIGURE 11-160  Pressure on the superior aspect of the hepatic flexure, produced by the liver edge.

FIGURE 11-161  Pressure defect on the proximal descending colon, produced by the spleen.



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

FIGURE 11-162  Simulated mass in the descending colon, produced by the spinous process of the adjacent lumbar vertebra.

A

C

B

D

FIGURE 11-163  A through D, Four examples of large ileocecal valves that simulate polypoid masses.

983

984

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

A

B

FIGURE 11-164  Retrograde prolapse of the ileocecal valve simulating a neoplasm of the terminal ileum. A, Before prolapse. B, After prolapse. (From Hatten HP Jr, et al: Retrograde prolapse of the ileocecal valve. AJR Am J Roentgenol 128:755, 1977.)

FIGURE 11-165  Mobile cecum with the ileocecal valve entering from the right side.



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

985

FIGURE 11-166  Top left, Intussusception of the base of the normal appendix on low-pressure barium enema (m). Top right, Partial reduction and filling of the appendix with medium pressure. Bottom, Complete reduction with high pressure. Note the small filling defects in the cecal mucosa in the top right and bottom figures, representing lymphoid follicles.

A

B

FIGURE 11-167  Prominent but normal haustral pattern in a healthy 40-year-old man. Note the simulation of diverticula. A, Preevacuation. B, Postevacuation.

986

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

A

B

FIGURE 11-168  Paucity of haustral markings in the left half of the colon is not uncommon in normal individuals and those with prolonged cathartic abuse. This appearance may simulate that of chronic ulcerative colitis. A, Preevacuation. B, Postevacuation. (Ref: Plum GE, et al: Prolonged cathartic abuse resulting in roentgen evidence suggestive of enterocolitis. Am J Roentgenol Radium Ther Nucl Med 83:919, 1960.)

FIGURE 11-169  Colon shown by double contrast with a pattern that simulates the small bowel, probably the result of barium in the innominate grooves.



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

A

987

B

FIGURE 11-170  A, Physiologic colonic sphincter simulating colonic neoplasm. B, The alteration is not seen in the postevacuation film. (Ref: Templeton AW: Colon sphincters simulating organic disease. Radiology 75:237, 1960.)

A

B

FIGURE 11-171  A, Additional example of a physiologic sphincter simulating a neoplasm. B, It is not seen in the follow-up examination. (Ref: Cimmino CV: Roentgen-diagnostic value of spasm of certain colonic “sphincters.” Va Med Mon 92:317, 1965.)

988

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

FIGURE 11-172  Two examples of a physiologic sphincter closely resembling an annular carcinoma.

FIGURE 11-173  Elongation, elevation, and narrowing of the pelvic colon secondary to fat accumulation in the pelvis. This entity should not be confused with the changes caused by pelvic neoplasm. (Ref: Fogg LB, Smyth JW: Pelvic lipomatosis: A condition simulating pelvic neoplasm. Radiology 90:558, 1968.)



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

A

C

B

D

FIGURE 11-174  Pelvic and ileocecal lipomatoses in the same patient. A, B, Narrowing and straightening of the rectum and sigmoid by fat. C, Fatty infiltration of the ileocecal valve. D, CT scan showing huge amounts of perirectal fat.

989

990

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

FIGURE 11-175  Additional example of the colonic changes caused by pelvic lipomatosis.

FIGURE 11-176  Preevacuation and postevacuation films showing displacement of the sigmoid colon by the iliopsoas muscle. A similar defect may be seen in the ascending colon and the terminal ileum in some patients. (Refs: Martel W: Displacement of the intestine by the iliopsoas muscle. Am J Roentgenol Radium Ther Nucl Med 94:399, 1965; Duprat G Jr, et al: Bowel displacement due to psoas muscle hypertrophy. Can Assoc Radiol 34:64, 1983.)



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

991

FIGURE 11-177  Preevacuation and postevacuation films of the rectum in lateral projection, showing an increase in the retrorectal space that is caused by obesity, not interposed disease. This finding may also be seen in Cushing’s disease. (Refs: Fennessy JJ, et al: Early roentgen manifestations of mild ulcerative colitis and proctitis. Radiology 87:848, 1966; Yagan R, Marmslya G: Increased retrorectal space on barium enema in pelvic lipomatosis. Appl Radiol 17:36, 1988.)

A

B

FIGURE 11-178  Barium in the innominate folds of the hepatic flexure simulating mucosal ulceration. A, Preevacuation film does not demonstrate the folds. B, Postevacuation film nicely shows the barium in the folds. (Ref: Williams I: Innominate grooves in the surface of mucosa. Radiology 84:877, 1965.)

992

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

FIGURE 11-179  Two examples of the innominate grooves of the colon. These can be distinguished from ulcerations by their inconsistency. (Refs: Frank DF, et al: Pseudoulcerations of the colon on barium examination. Gastrointest Radiol 2:129, 1977; Cole FM: Innominate grooves of the colon: Morphological characteristics and etiologic mechanisms. Radiology 128:41, 1978.)

A

B

FIGURE 11-180  Lymphoid follicles in healthy children. A, A 3-year-old child. B, A 13-year-old child. These lesions are not believed to be of significance but may be confused with polyposis coli. (Ref: Laufer I, deSa D: Lymphoid follicular pattern: A normal feature of the pediatric colon. AJR Am J Roentgenol 130:51, 1978.)



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

993

A

B FIGURE 11-181  Two examples of lymphoid follicles of the colon in adults, a finding of no clinical significance. A, A 63-year-old man. B, A 43-year-old man. (Ref: Kelvin FM, et al: Lymphoid follicular pattern of the colon in adults. AJR Am J Roentgenol 133:821, 1979.)

FIGURE 11-183  “Rectal ears” in a 1-month-old infant. These are transitory protrusions of the rectum into the inguinal rings. (Ref: Kassner EG, et al: “Rectal ears.” J Can Assoc Radiol 26:125, 1975.) FIGURE 11-182  Fat droplets in the colon after castor oil ingestion, simulating polypoid lesions.

994

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

A

B

C

D

FIGURE 11-184  Pressure effect of a full bladder on the sigmoid colon. A, B, Full bladder. C, D, After bladder is emptied. (Ref: Kleinhaus J, Kaftori U: Rectosigmoid pseudostenosis due to urinary retention. Radiology 127:645, 1978.)



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

FIGURE 11-185  Another example of the effect of a distended urinary bladder on the rectosigmoid colon.

995

996

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

FIGURE 11-186  Two examples of the impressions of the levator ani muscles on the rectum in children.

FIGURE 11-187  Two examples of “kissing” artifacts produced by contact of the rectal balloon and the rectal wall. (Ref: Gohel VK, et al: Double-contrast artifacts. Gastrointest Radiol 3:139, 1978.)



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

A

997

B FIGURE 11-188  A, “Kissing” artifacts of the rectum produced by balloon contact. B, After removal of balloon.

FIGURE 11-189  Two examples of alterations seen in double-contrast examinations, caused by strands of mucus. This finding should not be confused with linear ulceration.

998

The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

A

B FIGURE 11-190  A, “Kissing” artifact simulating a polyp in the transverse colon, produced by apposition of two folds. B, Film made with the patient in the left lateral decubitus position shows no lesion.

FIGURE 11-191  Two examples of sacral foramina projecting through the colon, simulating filling defects.

FIGURE 11-192  Leakage of barium into the vagina during a barium enema simulates extravasation caused by a rupture of the rectum.



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

FIGURE 11-193  Pelvic phleboliths simulating colonic diverticula on barium enema study.

FIGURE 11-194  Visualization of both walls of the rectum.

999

1000 The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

The Liver and Biliary Tract

A

FIGURE 11-195  Differences in proportion in the size of the liver and the total abdominal area in a child (A) and an adult (B). The child’s liver occupies a proportionately larger portion of the abdomen. (From Keats TE: Pediatric radiology: Some potentially misleading variations from the adult. Va Med Mon 93:630, 1966.)

B

FIGURE 11-196  Riedel’s lobe of the liver simulating an abdominal mass. (Ref: Reitemeier HR, et al: Riedel’s lobe of the liver. Gastroenterology 34:1090, 1958.)



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT 1001

FIGURE 11-197  Additional examples of Riedel’s lobe.

FIGURE 11-198  Normal common duct visualized tomographically by virtue of its surrounding periductal fat. (Ref: Shaub MS, et al: Peribiliary fat: A new roentgenographic finding. Am J Roentgenol Radium Ther Nucl Med 123:330, 1975.) This entity may be confused with pneumobilia. (Ref: Govoni AF, Meyers MA: Pseudopneumobilia. Radiology 118:526, 1976.)

A

B

C

FIGURE 11-199  A through C, Three examples of the pylorus of the stomach simulating a fissured biliary calculus. In B and C, the air in the duodenal bulb simulates emphysematous cholecystitis with stone.

1002 The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

FIGURE 11-200  Accessory hepatic duct entering low in the common duct.

FIGURE 11-201  Accessory right hepatic duct.

FIGURE 11-202  Intramural cystic duct remnant. This portion of the cystic duct lies within the wall of the common duct and is not detectable at cholecystectomy.



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT 1003

FIGURE 11-203  Left, Pseudocalculus sign seen in cholangiography is produced by muscular contraction of the distal end of the duct and should not be mistaken for a calculus. Right, Second film in the same examination does not show the defect. (Ref: Mujahed Z, Evans JA: Pseudocalculus defect in cholangiography. Am J Roentgenol Radium Ther Nucl Med 116:337, 1972.)

A

B FIGURE 11-204  A, Pseudocalculus sign in a dilated biliary tree. B, Normal appearance after contraction has been relieved.

1004 The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT

FIGURE 11-205  Pseudocalculus sign, with a small amount of contrast material in the duct, simulating a stone.

FIGURE 11-206  Low insertion of the cystic duct (m), resulting in a very short common duct (m 6 ).

A

FIGURE 11-207  Duplication of the distal end of the pancreatic duct shown on endoscopic retrograde cholangiopancreatography.

B FIGURE 11-208  A, Contrast agent and food in the duodenal bulb simulate a gallbladder with stones on cholangiography. B, After peristalsis has cleared the duodenum.



The Soft Tissues of the Abdomen  |  THE GASTROINTESTINAL TRACT 1005

FIGURE 11-210  Costal cartilage mistaken for stones in the right hepatic duct.

FIGURE 11-209  Two examples of the accessory duct of Santorini arising from the duct of Wirsung.

CHAPTER

12

The Soft Tissues of the Pelvis PAGES 1006 to 1015

FIGURES THE SOFT TISSUES OF THE PELVIS

12-1 to 12-34

THE SOFT TISSUES OF THE PELVIS

FIGURE 12-1  Circular areas of radiolucency caused by fat in the buttocks.

1006

FIGURE 12-2  Shadows of the levator ani muscles (m). The obturator internus muscles are also seen (m 66). (Ref: Levene G, Kaufman SA: The diagnostic significance of roentgenologic soft tissue shadows in the pelvis. Am J Roentgenol Radium Ther Nucl Med 79:697, 1958.)



The Soft Tissues of the Pelvis  |  THE SOFT TISSUES OF THE PELVIS 1007

A

B

FIGURE 12-3  Contraction of the levator ani muscles produces evanescent shadows in the pelvis in a given patient. A, Levator ani muscles not seen. B, Same patient with muscle contractions, showing intrusion upon the bladder outline.

FIGURE 12-4  Stripes of radiolucency caused by fat accumulations between the muscle bundles of the gluteus maximus. FIGURE 12-5  Shadow of the uterus seen indenting the superior aspect of the contrast-filled urinary bladder.

1008 The Soft Tissues of the Pelvis  |  THE SOFT TISSUES OF THE PELVIS

FIGURE 12-7  Unusual configuration of pelvic phleboliths, elongated on the patient’s right (m) and bifid on the left (m 66).

FIGURE 12-6  Calcified venous thrombus in the iliac vein.

FIGURE 12-8  Sigmoid colon simulating a pelvic mass.

FIGURE 12-9  Visualization of the bladder wall as a result of the difference in radiographic density between muscle and urine.



The Soft Tissues of the Pelvis  |  THE SOFT TISSUES OF THE PELVIS 1009

FIGURE 12-10  Fluid-filled loops of small bowel may simulate the “dog ear” sign of intraperitoneal fluid.

FIGURE 12-11  Examples of calcification in Cooper’s ligament. This is seen in the elderly as an unusual form of physiologic calcification. (Ref: Steinfeld JR, et al: Calcification in Cooper’s ligament. Am J Roentgenol Radium Ther Nucl Med 121:107, 1974.)

FIGURE 12-12  Unusually extensive calcification in Cooper’s ligament.

1010 The Soft Tissues of the Pelvis  |  THE SOFT TISSUES OF THE PELVIS

FIGURE 12-13  Calcified epiploic appendages that have fallen into the pelvis shift from side to side, as illustrated in this patient. (Refs: Holt JF, MacIntyre AS: Calcified omental fat deposits: Their roentgenologic significance. AJR Am J Roentgenol 60:612, 1984; Borg SA, et al: A mobile calcified amputated appendix epiploica. AJR Am J Roentgenol 127:349, 1976.)

FIGURE 12-15  Visualization of the ureters without contrast agent, by virtue of periureteral fat.

FIGURE 12-14  Densities in the right side of the pelvis representing ingested bone meal. This appearance might be misinterpreted as psammomatous calcification of an ovarian malignancy. (Ref: Schabel S, Rogers CI: Opaque artifacts in a health faddist simulating ovarian neoplasm. AJR Am J Roentgenol 130:789, 1978.)

A

B FIGURE 12-16  A, B, Examples of calcification of the sacrospinous ligaments.



The Soft Tissues of the Pelvis  |  THE SOFT TISSUES OF THE PELVIS 1011

FIGURE 12-17  Calcification in the anterior sacral ligament (m) and in the sacrotuberous ligament (m 6).

A

B FIGURE 12-18  Calcification of the sacrotuberous ligaments. A, Frontal projection. B, Lateral projection.

1012 The Soft Tissues of the Pelvis  |  THE SOFT TISSUES OF THE PELVIS

FIGURE 12-19  Long linear calcification of the sacrotuberous ligaments.

A

B FIGURE 12-20  Calcification in the piriform muscles in an 82-year-old woman.



The Soft Tissues of the Pelvis  |  THE SOFT TISSUES OF THE PELVIS 1013

FIGURE 12-22  Calcification in the inferior pubic ligaments.

FIGURE 12-21  Calcification, probably within the coccygeoanal ligament.

FIGURE 12-23  Ossification of the obturator foramen. (Ref: Birkner R, Consentius K: Ossification in the wall of the foramen obturatum. Rofo 127:72, 1977.)

FIGURE 12-24  Multiple pelvic phleboliths of varying sizes.

1014 The Soft Tissues of the Pelvis  |  THE SOFT TISSUES OF THE PELVIS

FIGURE 12-25  Huge phleboliths in a 94-year-old woman.

FIGURE 12-26  Phlebolith in the spermatic cord.

FIGURE 12-28  Calcification in the corpora cavernosa.

FIGURE 12-27  Vulvar phleboliths.

FIGURE 12-29  Calcification of the uterine arteries in an elderly woman.

FIGURE 12-30  Calcification of the fallopian tubes in an elderly woman.

FIGURE 12-31  Unilateral calcification of the fallopian tube in an 80-year-old woman.

FIGURE 12-32  Two examples of calcified seminal vesicles. Left, A 50-year-old man. Right, A 71-year-old man.

FIGURE 12-33  Calcified thrombus of the right iliac vein. FIGURE 12-34  Calcified venous thrombus simulating a lesion in the femoral head.

CHAPTER

13

The Genitourinary Tract PAGES



FIGURES

1016 to 1038

THE KIDNEYS

13-1 to 13-52

1039 to 1046

THE URETERS

13-53 to 13-72

1046 to 1051

THE BLADDER

13-73 to 13-87

1052 to 1055

THE URETHRA

13-88 to 13-96

1055 to 1057

THE GENITAL TRACT

13-97 to 13-101

THE KIDNEYS

FIGURE 13-1  Apparent absence of one psoas muscle. This finding is seen in many normal individuals and is not necessarily of significance. (Ref: Elkin M, Cohen G: Diagnostic value of psoas shadow. Clin Symp 13:210 1962.) Asymmetry of the psoas muscle is quite common and is usually of no clinical significance. (Ref: Goldfeld M, Loberant N: Unilateral “vanishing psoas”: An anatomic variant. Clin Imaging 17:104, 1993.)

1016



The Genitourinary Tract  |  THE KIDNEYS 1017

FIGURE 13-2  Low-lying left kidney. The left kidney lies at a level lower than the right in 5% of normal individuals. Therefore this finding is not necessarily indicative of displacement. (Ref: McClelland RE: A low-lying left kidney. J Urol 75:198, 1956.)

FIGURE 13-3  Unusual configuration of the right kidney produced by rotation on its axis. This finding was proven by CT scan.

FIGURE 13-4  Costophrenic sulcus and the edge of the lung producing an unusual appearance in the nephrogram of the right kidney.

FIGURE 13-5  Splenic impression (m) on the left kidney that produces a “bump” in its midportion. (Ref: Olutola PO, et al: Unusual renal distortion and displacement caused by the spleen. Pediatr Radiol 12:185, 1982.)

1018 The Genitourinary Tract  |  THE KIDNEYS

A

B

FIGURE 13-6  Hepatic impression (m) on the right kidney that produces a “bump” in its midportion (m 66). A, Urogram. B, Angiogram. (Ref: Doppman JL, Shapiro R: Some normal renal variants. Am J Roentgenol Radium Ther Nucl Med 92:1380, 1964.)

FIGURE 13-7  Fetal lobulation of the kidneys.

FIGURE 13-8  Nonsignificant variation in the outline of the right kidney.



The Genitourinary Tract  |  THE KIDNEYS 1019

FIGURE 13-9  Two examples of the dromedary left kidney, an anatomic variation that simulates a mass lesion. (Ref: Harrow BR, Sloane JA: The dromedary left kidney. Am J Roentgenol Radium Ther Nucl Med 88:144, 1962.)

FIGURE 13-10  Gastric fundus simulating a suprarenal mass. A, Before ingestion of barium. B, After ingestion of barium. (Ref: Martire JR, Goldman SM: Left suprarenal pseudotumor. Radiobiologiia 17:12, 1977.) This pseudotumor may opacify on angiography and further obscure its proper identification. (Ref: Bjorn-Hansen RW, O’Brien DS: Aortographic opacification of the gastric fundus simulating neoplasm. Am J Roentgenol Radium Ther Nucl Med 100:408, 1967.)

A

B

FIGURE 13-11  Two examples of spurious suprarenal masses produced by the duodenal bulb. Left, Fluid- and air-filled. Right, fluid-filled.

1020 The Genitourinary Tract  |  THE KIDNEYS

FIGURE 13-12  Two examples of renal pseudotumors produced by the spleen. (Ref: Madayag M, et al: Renal and suprarenal pseudotumors caused by variations of the spleen. Radiology 105:43, 1972.)

FIGURE 13-13  Pelvic kidney.



The Genitourinary Tract  |  THE KIDNEYS 1021

FIGURE 13-14  Ptotic right kidney. Note the configuration of its collecting system and its position in the lateral projection.

A

B

FIGURE 13-15  Variations in renal outline of the right kidney with respiration. A, Expiration. B, Inspiration.

1022 The Genitourinary Tract  |  THE KIDNEYS

A

C

B FIGURE 13-16  Anterior displacement and rotation of the kidneys by retroperitoneal fat. A, Year 1: Normal appearance of kidneys. B, Year 9: The contour of the right kidney has altered and appears shorter in its vertical dimensions. C, CT scan shows anterior displacement of the right kidney by fat. (Ref: Hooge WA, et al: Anterior displacement of kidneys by fat. J Can Assoc Radiol 31:143, 1980.)

A

B

FIGURE 13-17  Duplication variant producing a discrepancy in renal size. The left kidney is duplex and is distinctly larger than the right. A, Plain film. B, Urogram.



The Genitourinary Tract  |  THE KIDNEYS 1023

A

B

FIGURE 13-18  A, Costal cartilage calcification simulating renal calculi. B, Calcification is obscured by the contrast material on the urogram.

FIGURE 13-19  Multiplicity of calyces. This is an atavistic variant that may be mistaken for a disease state.

FIGURE 13-20  Unicalyx kidney. Another atavistic variant, it represents the normal arrangement in monkeys, dogs, and rabbits. (Ref: Harrison RB, et al: A solitary calyx in a human kidney. Radiology 121:310, 1976.)

1024 The Genitourinary Tract  |  THE KIDNEYS

FIGURE 13-21  Megacalyces of the left kidney. This variant is often unilateral and represents a malformation of the renal papillae. The cortex is normal, but the medulla is hypoplastic. The dilated calyces and reduced parenchymal thickness resemble obstructive hydronephrosis or postobstructive atrophy. (Ref: Talner LB, Gittes RF: Megacalyces: Further observations and differentiation from obstructive renal disease. Am J Roentgenol Radium Ther Nucl Med 121:473, 1974.)

A

B FIGURE 13-22  A, Megacalyces of the right kidney. B, Detailed view of the right kidney.



The Genitourinary Tract  |  THE KIDNEYS 1025

FIGURE 13-23  Bilateral megacalyces. This condition may be genetically transmitted. (Ref: Lam AH: Familial megacalyces with autosomal recessive inheritance: Report of 3 affected siblings. Pediatr Radiol 19:28, 1988.)

A

B

FIGURE 13-24  Two examples of extrarenal collecting systems. The clawlike configuration of the infundibula, best seen in the right kidney in A, is characteristic of this variation in development. Fifty percent of affected individuals have associated renal disease. B, Bilateral extrarenal collecting systems. (Ref: Malament M, et al: Extrarenal calyces: Their relationship to renal disease. Am J Roentgenol Radium Ther Nucl Med 86:823, 1961.)

1026 The Genitourinary Tract  |  THE KIDNEYS

FIGURE 13-25  Miniature calyx. Tubular blush, produced by contrast material in the collecting tubules, is seen as a halo around this calyx. (Ref: Kunin M: The abortive calix: Variations in appearance and differential diagnosis. AJR Am J Roentgenol 139:931, 1982.)

FIGURE 13-26  Accessory calyx arising from the lower calyceal group.

FIGURE 13-27  Small calyceal diverticulum.



The Genitourinary Tract  |  THE KIDNEYS 1027

FIGURE 13-28  Calyceal diverticulum. Left, Early filling. Right, Late filling.

FIGURE 13-29  Calyx seen on end, simulating a filling defect. FIGURE 13-30  Aberrant renal papilla entering the infundibulum of the lower pole. (Ref: Binder R, et al: Aberrant papillae and other filling defects of the renal pelvis. Am J Roentgenol Radium Ther Nucl Med 114:746, 1972.)

1028 The Genitourinary Tract  |  THE KIDNEYS

A

B

FIGURE 13-31  Aberrant renal papilla entering the renal pelvis. This variant may be associated with hematuria.

FIGURE 13-32  Another example of an aberrant renal papilla entering the renal pelvis.



The Genitourinary Tract  |  THE KIDNEYS 1029

FIGURE 13-33  Flat upper pole calyceal groups that might be mistaken for distortion by an adjacent mass.

FIGURE 13-35  Large composite upper pole calyceal groups. FIGURE 13-34  Composite upper pole calyces.

1030 The Genitourinary Tract  |  THE KIDNEYS

A

C

B

FIGURE 13-36  A, B, Mucosal folds seen within calyces and infundibula. C, Tomogram of left kidney shows the folds in the superior calyx. These folds do not indicate abnormality.



The Genitourinary Tract  |  THE KIDNEYS 1031

A

B

FIGURE 13-37  A, Incomplete filling of the calyces and infundibula may simulate a mass lesion. B, With adequate filling, the mass effect is no longer seen.

A

B

FIGURE 13-38  Bulge in the suprahilar region of the right kidney representing the hilar lip or renal uncus. A, Urogram. B, Nephrotomogram. (Ref: Feldman AE, et al: Renal pseudotumors: An anatomic-radiologic classification. J Urol 120:133, 1978.)

1032 The Genitourinary Tract  |  THE KIDNEYS

C

B

A

FIGURE 13-39  Deformity of the collecting system caused by excessive invagination of the cortical tissue in forming Bertin’s columns. This entity is often found in cases with duplications of the collecting system and may simulate a neoplasm. A, Plain film. B, Arteriogram. C, Nephrogram. (Ref: Lopez FA: Renal pseudotumors. Am J Roentgenol Radium Ther Nucl Med 109:172, 1970.)

A

B

FIGURE 13-40  A, Additional example of the deformity of the collecting system caused by Bertin’s columns. B, Nephrogram.



The Genitourinary Tract  |  THE KIDNEYS 1033

FIGURE 13-41  Renal pelvic lipomatosis. The deposition of large amounts of normal fat in the renal pelvis produces radiolucency, stretching, and elongation of the infundibula, best seen in the right kidney (m). On occasion it may resemble the changes of polycystic disease as seen in the left kidney (m 6). (Ref: Ambos MA, et al: Replacement lipomatosis of the kidney. AJR Am J Roentgenol 130:1087, 1978.)

A

B

D

C FIGURE 13-42  Backflow. A, Pyelovenous. B, Pyelolymphatic. C, Pyelotubular. D, Tubular blush produced by contrast material in the collecting tubules of the renal papillae. This should not be mistaken for the tubular ectasia of the medullary sponge kidney. (Ref: Ohlson L: Normal collecting ducts: Visualization at urography. Radiology 170:33, 1989.)

1034 The Genitourinary Tract  |  THE KIDNEYS

FIGURE 13-43  Accessory renal hilus. Left, Nephrogram shows a defect in the superior pole of the kidney (m). Right, Renal angiogram shows a renal artery entering the kidney at the area of the defect. A separate renal artery supplies the remainder of the kidney. (Courtesy Dr. Thomas F. Stephenson.)

FIGURE 13-44  Two examples of vascular impressions on the renal pelvis. Most such impressions are not clinically important. (Ref: Baum S, Gillenwater JY: Renal artery impressions on renal pelvis. J Urol 95:139, 1966.)



The Genitourinary Tract  |  THE KIDNEYS 1035

A

C

B

D

FIGURE 13-45  Four additional examples of vascular impressions on the collecting systems. (Ref: Nebesar RA, et al: Renal vascular impression: Incidence and clinical significance. Am J Roentgenol Radium Ther Nucl Med 101:719, 1967.)

1036 The Genitourinary Tract  |  THE KIDNEYS

FIGURE 13-46  Tortuous infundibulum.

FIGURE 13-47  Unusual bifid collecting system.

FIGURE 13-48  Abortive duplication of the renal pelvis.



The Genitourinary Tract  |  THE KIDNEYS 1037

A

B

FIGURE 13-49  Two examples of extrarenal pelves that simulate the changes of hydronephrosis. A, Bilateral extrarenal pelves. B, Duplicated extrarenal pelvis of the right kidney only.

FIGURE 13-50  Very large extrarenal pelves.

1038 The Genitourinary Tract  |  THE KIDNEYS

B

A

FIGURE 13-51  A, Simulated hydronephrosis produced by massive distention of the bladder (m). B, Appearance after bladder emptying.

A

B

FIGURE 13-52  “Yo-yo” effect (saddle reflux) of pelvic emptying in duplex kidneys. A, The upper segment of the right kidney is emptying, and the lower segment filling. B, The lower segment contracts, and the upper segment fills by reflux. These are normal dynamics in duplex kidneys. The transient distention of the upper segment could be misinterpreted as pathologic dilatation. (Ref: Privett JT, et al: The incidence and importance of renal duplication. Clin Radiol 27:521, 1976.)



The Genitourinary Tract  |  THE URETERS 1039

THE URETERS

FIGURE 13-53  “Pigtail” renal pelvis showing an unusual course of the proximal portion of the ureter.

A

FIGURE 13-54  Transverse folds in the proximal ureter are a normal variation in infants. They are believed to represent a persistence of normal fetal tortuosities. (From Kirks DR, et al: Transverse folds in the proximal ureter: A normal variation in infants. AJR Am J Roentgenol 130:463, 1978.) Similarly, longitudinal striations in adults are believed to be normal as well. (Ref: Parker MD, Clark RL: Urothelial striations revisited. Radiology 198:89, 1996.)

B

FIGURE 13-55  Normal deviations of the ureter caused by the iliopsoas muscles. (Ref: Levine RB, et al: Ureteral deviation caused by iliopsoas hypertrophy. Am J Roentgenol Radium Ther Nucl Med 107:756, 1969.)

1040 The Genitourinary Tract  |  THE URETERS

A

B FIGURE 13-56  Peristalsis of the ureters should not be mistaken for pathologic changes.

A

B

FIGURE 13-58  Variation in the position of the ureters with the technique of exposure. A, In the true lateral position, the upper kidney and ureter drop anteriorly. B, In the cross-table lateral view, the location of the ureters and kidneys can be compared more accurately. (Ref: Cook K, et al: Determination of the normal position of the upper urinary tract on the lateral abdominal urogram. Radiology 99:499, 1971.)

FIGURE 13-57  Full column filling of the ureters secondary to distention of the urinary bladder.



The Genitourinary Tract  |  THE URETERS 1041

FIGURE 13-59  Retrocaval ureter coursing around the posterior aspect of the inferior vena cava. (Ref: Emmett JL, Witten DM: Clinical Urography, 3rd ed. Philadelphia, WB Saunders, 1971.)

A

FIGURE 13-60  Retroiliac artery ureter, which was proven by angiography. (Ref: Hock E, et al: Retroiliac ureter: A case report. J Urology 107:37, 1972.)

B FIGURE 13-61  Effects of respiration on ureteral configuration. A, Inspiration. B, Expiration.

FIGURE 13-62  Periureteral fat enables the left ureter to be visualized without the use of a contrast agent.

1042 The Genitourinary Tract  |  THE URETERS

FIGURE 13-63  Medial deviation of the distal ureters as a normal variant caused by iliopsoas hypertrophy and not secondary to retroperitoneal fibrosis. (Ref: Saldino RM, Palubinskas AJ: Medial placement of the ureters: A normal variant which may simulate retroperitoneal fibrosis. J Urol 107:582, 1972.)

A

B

FIGURE 13-64  Ureteral displacement by hypertrophy of the iliopsoas muscles. This is a misleading finding, seen particularly in muscular young men, and may be unilateral. (Ref: Levine RB, et al: Ureteral deviation caused by iliopsoas hypertrophy. Am J Roentgenol Radium Ther Nucl Med 107:756, 1969.)



The Genitourinary Tract  |  THE URETERS 1043

B

A FIGURE 13-65  A, Medial deviation of the ureters by hypertrophied iliopsoas muscles. B, The muscles also cause medial displacement of the bladder. (Ref: Wechsler RJ, Brennan RE: Teardrop bladder: Additional considerations. Radiology 144:281, 1982.)

FIGURE 13-66  Two examples of unilateral deviation of the ureter caused by unilateral iliopsoas hypertrophy, both proven at laparotomy. (Ref: Ziter FM: Unilateral ureteral deviation caused by iliopsoas muscle hypertrophy. J Can Assoc Radiol 25:327, 1974.)

1044 The Genitourinary Tract  |  THE URETERS

FIGURE 13-67  Deviation of the distal right ureter caused by an ectatic iliac artery in an elderly man.

A

B

FIGURE 13-68  Three examples of blind duplication of the ureters. A, Termination at the renal pelvis. B, C, Termination in the pelvis. (Ref: Albers DD, et al: Blind-ending branch of a bifid ureter: Report of three cases. J Urol 99:160, 1968.)

C



The Genitourinary Tract  |  THE URETERS 1045

B

A

FIGURE 13-69  A, Pseudoectopic ureter seen in the prone position, in which the contrast material in the bladder gravitates toward the head into the dependent anterior dome and leaves the trigone area filled with nonopacified urine. The distal ureters appear to extend below the bladder. B, Supine film does not show the same effect. (Ref: Riggs W Jr, Seibert J: Pseudoectopic ureter on prone urogram. Radiology 106:391, 1973.)

FIGURE 13-70  A, B, Two examples of the ureteral jet phenomenon. A stream of opaque medium leaving the ureter may simulate an anomalous configuration of the ureter (m). Note the impaction of the jet on the bladder wall in A (m 6). (Ref: Kalmon EH, et al: Ureteral jet phenomenon; stream of opaque medium simulating anomalous configuration of ureter. Radiology 65:933, 1955.)

A

B

FIGURE 13-71  Asymmetry of the pelvic ureters in normal females is a normal variation. Note the medial deviation of the distal right ureter in this patient. (Ref: Kabakian HA, et al: Asymmetry of the pelvic ureters in normal females. AJR Am J Roentgenol 127:723, 1976.)

1046 The Genitourinary Tract  |  THE BLADDER

A

B

FIGURE 13-72  A, Apparent filling defect in the distal left ureter, resulting from peristalsis. B, After the peristaltic wave has passed, the impression is no longer seen.

THE BLADDER

A

B FIGURE 13-73  Proportional difference in size between the bladder and the total abdomen in the infant (A) and adult (B). The bladder in the infant (and in the child) is capable of a much greater proportional degree of distention. (From Keats TE: Pediatric radiology: Some potentially misleading variations from the adult. VA Med Mon 93:630, 1966.)



The Genitourinary Tract  |  THE BLADDER 1047

A

B FIGURE 13-74  A, Normal distention of the bladder displacing the small bowel in a 2-year-old child. B, After voiding.

FIGURE 13-75  Visualization of the bladder wall as a result of the difference in radiographic density between muscle and urine and perivesical fat.

1048 The Genitourinary Tract  |  THE BLADDER

FIGURE 13-76  Perivesical fat simulating emphysematous cystitis.

FIGURE 13-77  “Bladder ears,” a transitory extraperitoneal herniation of the bladder in infants. This finding is believed to represent a transient variation in normal development. (Ref: Allen RP, Condon VR: Transitory extraperitoneal hernia of the bladder in infants (bladder ears). Radiology 77:979, 1961.) FIGURE 13-78  A striking example of perivesical fat.

FIGURE 13-79  Examples of unilateral “bladder ears.”



The Genitourinary Tract  |  THE BLADDER 1049

FIGURE 13-80  “Bladder ears” caused by laxity of the inguinal rings in a 53-year-old woman.

A

B

FIGURE 13-81  Uterine impression on the bladder in two patients. A, Shadow of the uterus is seen indenting the bladder. B, Shadow of the uterus is not seen above the impression on the bladder.

FIGURE 13-82  Normal physiologic variations in the contour of the base of the bladder during voiding. Note the asymmetric urethral distention in A (m) and the indentation produced posteriorly by the trigonal plate in B (m). (Ref: Shopfner CE, Hutch JA: The normal urethrogram. Radiol Clin North Am 6:165, 1968.)

A

B

1050 The Genitourinary Tract  |  THE BLADDER

FIGURE 13-83  Elevation and elongation of the bladder caused by accumulation of large amounts of fat in the pelvis. (Ref: Fogg LB, Smyth JW: Pelvic lipomatosis: A condition simulating pelvic neoplasm. Radiology 90:558, 1968.)

A

B

C FIGURE 13-84  Unusual configuration of the bladder caused by large psoas muscles. A, Frontal projection. B, Lateral projection. C, CT scan.



The Genitourinary Tract  |  THE BLADDER 1051

FIGURE 13-85  Gas in the rectum seen as a radiolucency within the contrastfilled bladder, simulating the filling defect caused by a bladder neoplasm.

FIGURE 13-86  Trigone of the bladder. Top left, A 6-year-old boy. Top right, An 8-year-old boy. Bottom, A 29-year-old woman.

FIGURE 13-87  The “female prostate,” an indentation in the base of the bladder produced by asymmetry of the symphysis pubis. (Ref: Pope TL Jr, et al: Bladder base impressions in women: “Female prostate.” AJR Am J Roentgenol 136:1105, 1981.)

1052 The Genitourinary Tract  |  THE URETHRA

THE URETHRA

FIGURE 13-88  Prostatic utricle in an 8-year-old boy, not to be mistaken for a diverticulum.

A

FIGURE 13-89  Plicae colliculi, not to be mistaken for valves.

B

FIGURE 13-90  Two examples of normal intermuscular incisurae of the posterior urethra. A, A 19-year-old man. B, An 11-year-old boy. (Ref: Shopfner CE, Hutch JA: The normal urethrogram. Radiol Clin North Am 6:165, 1968.)



The Genitourinary Tract  |  THE URETHRA 1053

B

A FIGURE 13-91  Another example of intermuscular incisurae of the posterior urethra, this one in an 11-year-old boy. A, Urethra distended by retrograde injection. B, During voiding. Note the shadows of the verumontanum (m) and mucosal folds (m 66).

A

B

FIGURE 13-92  A, Voiding film. The external sphincter (m) and the insertion point of the suspensory ligament of the penis (m 6 ) should not be mistaken for areas of organic narrowing. B, Retrograde examination.

1054 The Genitourinary Tract  |  THE URETHRA

A

B FIGURE 13-93  Cowper’s glands, not to be mistaken for false passages.

FIGURE 13-94  Finger pressure causing an apparent stricture of the urethra. A similar defect can be produced by pressure on the lip of the collecting receptacle. (Ref: Lebowitz RL: Pseudostricture of the urethra: Urinal artifact on urethrography. AJR Am J Roentgenol 130:570, 1978.)

FIGURE 13-95  The “spinning top” urethra in a 6-year-old girl. This is believed to be a normal appearance seen in forceful voiding and is not the product of distal obstruction. (Ref: Whitaker J, Johnson GS: Correlation of urethral resistance and shape in girls. Radiology 91:457, 1968.) It has been stated, however, that this configuration is the result of unstable contractions that are resisted by a voluntary increase in distal sphincter tension to prevent leakage of urine, and that it does not represent a normal variant. (Ref: Saxton HM, et al: Spinning top urethra: Not a normal variant. Radiology 168:147, 1988.)



The Genitourinary Tract  |  THE GENITAL TRACT 1055

FIGURE 13-96  Phleboliths in the corpora cavernosa in a 40-year-old man, simulating urethral calculi.

THE GENITAL TRACT

B

A FIGURE 13-97 

Intravaginal voiding. A, Cystogram. B, Vaginal residue.

1056 The Genitourinary Tract  |  THE GENITAL TRACT

FIGURE 13-99  Normal filling of the endocervical glands on hysterosalpingography. FIGURE 13-98  Arcuate uterus seen on hysterosalpingography. The impression in the fundus was misinterpreted as a myoma.

FIGURE 13-100  Uterus didelphys and complete vaginal septum constituting duplication of the vagina and uterus. (Ref: O’Neill MJ, et al: Imaging evaluation and classification of developmental anomalies of the female reproductive system with an emphasis on MR imaging. AJR Am J Roentgenol 173:407, 1999.)



The Genitourinary Tract  |  THE GENITAL TRACT 1057

A

B

C

D

FIGURE 13-101  Normal variants in the hysterosalpingography of the uterus. A, Double contour of the uterus. B, Gartner duct cyst communicating with the uterine lumen. C, Infantile uterus in a 30-year-old woman. D, Myometrial folds in a 34-year-old woman. (From Ubeda B, et al: Hysterosalpingography: Spectrum of normal variants and nonpathologic findings. AJR Am J Roentgenol 177:131, 2001.)

Index Note: numbers in italic indicate online-only material. “S” refers to online-only chapter supplements. A Abdomen, 923–942 air in appendix in, 938 air beneath breasts in, 929 air–fluid levels in, 927, 928, 929 antrum in, 935 calcified costal cartilage in, 939, 940 cecum in, 940, 980 colon in “double wall” sign of, 938 ingested seeds in, 940 interposition of in, 930, 931, 932 splenic flexure of, 936 superimposition on stomach in, 928 densities in upper, 793 diaphragmatic attachments in, 939 duodenal bulb in, 933 epiploic appendage in, 941, 942 fat in around liver, 929, 930 around spleen, 930 ligamentum teres of liver, 937 mesenteric, 938 perinephric, 937 between stomach and diaphragm, 927 gastric antrum in, 933 gastric contents in, 5S–163, 939 gastric fundus in, 934 hepatic shadow on, 923 jejunum loops of mid-, 973 liver in, 937, 1000 liver encroachment in, 934 lung margins in, 936 Mach effect in, 925 mass simulated in, 936, 1000 muscle splinting in, 925 peritoneal cavity of, 936 properitoneal fat line in, 937 psoas muscle and, 923, 924 pylorus in, 935 size of compared to bladder, 1046 compared to colon, 979 compared to liver, 1000 compared to stomach, 949 skin folds and appearance of, 923 soft tissues of, 922–1005 splenic artery calcification in, 940 subdiaphragmatic fat in, 925, 926 umbilical arteries in, 942 umbilicus shadow in, 939 Abductor pollicis longus tendon, 419 Accessory bone. See also specific bone. at base of distal phalanx of first toe, 754 of calcaneal tuberosity, 643 of cuboid, 707 of foot, 638 midline frontal, 27 at posterior margin of acetabulum, 279 unciform process ossification simulating, 434 Accessory sacroiliac joints, 240

Acetabular line, 275 Acetabular margins accessory bone at, 279 accessory elements arising from, 264 cyst simulated by superior, 282 traction spurs at, 280 Acetabulum, 275–284, 4S–134–4S–138. See also Hip; Protrusio acetabuli. apophysis of, 4S–137, 279 bone island in, 4S–137 chondroid stripes in, 276 defects in, 280 destructive lesion simulation in, 4S–137 exaggerated lucencies of, 281 femoral head and shadow of on, 7S–193 superimposition of on, 490 fossae in accessory, in apex of, 282 acetabular notches and, 4S–138 examples of, 281 at nutrient vessel entry point, 489 intrapelvic protrusion of, 489 irregularities of, 7S–192 lips of, 4S–137 lucent interval in, 280, 490 notch in appearance of, 4S–137 asymmetric, 4S–138 examples of, 283 second, 282 superior, 282 nutrient vessels in, 4S–134, 276, 489 ossicle of of lip of, 278 triradiate cartilage, 4S–134 ossification centers for accessory in a 14-year-old, 4S–134, 276, 277 in a 32-year-old, 279 femoral head fraction simulated by, 490 incomplete closure of, 278 of rim of, 4S–128 secondary, 4S–134, 4S–136, 277 un-united, 4S–137 protrusio acetabuli of, 275 radiolucent patches above, 275 roof of asymmetric, 282, 284 irregularity of, 276, 488 notching of, 282 sclerotic, 4S–138, 284 spurlike margins of, 4S–137 Achilles tendon, 7S–225, 7S–226, 635 Acoustic neuroma, 56 Acromial apophysis, 288, 289 Acromial fracture, 286 Acromioclavicular joint accessory ossicle in, 318 clavicle orientation at, 321 configuration variations in, 298

Acromioclavicular joint (Continued) separated, 5S–145 wide in dysplastic scapula, 312 and malalignment, 297 normal, 297, 299 resulting from positioning, 297 with shoulder rotation, 321 widening of, 297, 299 Acromioclavicular separation, 297, 298 Acromion process clavicle and, 320, 321 development of, 286 irregular ossification of, 288 ossification centers for, 285 of scapula accessory ossification center for, 289 apophyses of, 5S–141, 5S–142 crenated appearance of, 5S–143 fossae in, 5S–143 irregularity of, 289 long, 5S–141 malalignment of, 297 pseudospur in, 291 secondary ossification center for appearance of, 286 remnant of closure line of, 289 simulating fracture of, 290 for tip of, 297 stout, 5S–141 Adductor magnus muscle, 518 Adductor muscle femoral insertion of, 512 rider’s bone ossification in, 275 Adenoids, 764, 766 Adenopathy, 814 Air cyst, 824 Alveolar canal, 72 Ampulla of Vater, 972 Aneurysm, 878 “Angel-wing” sacrum, 239 Ankle. See also Talus. accessory skeletal elements in, 637 malleolus of Achilles tendon shadow on, 7S–225, 635 lateral foramen in, 635 fracture simulation of, 621, 633 os subfibulare at tip of, 632 lucency in, 636 medial bony flanges on, 630 cleft in, 623 closure failure in, 623 ossification of, 627, 628 ossification centers for, 627, 629 radiolucency in, 628 ossification centers for accessory, 631, 635 large separate, 629 secondary, 627, 628, 631

I-1

I-2

Index

Ankle (Continued) os subfibulare and with fossa in distal fibula, 633 fracture simulation by, 634 in oblique projection of, 633 os subtibiale in, 629 os talotibiale in, 635 os tibiale externum and, 745 ossicle in, 627 ossification centers for accessory, 629 posterior, 631 secondary, 634 pseudotalar tilt of, 636 soleus muscle and, 7S–226 stress views of normal, 636 Annular carcinoma, 988 Annular ligament, 397 Annulus fibrosus bulging, 3S–102, 201 calcification of, 160 Anterior fossa ethmoidal air cell and, 76 meningioma of, 1S–10, 28 pneumatization of, 75 scalloped appearance of, 1S–10 Antrum antral mucosa prolapsed into duodenal bulb, 966 diaphragmatic , 961, 962 gallbladder impression on, 972 gastric, 933, 961, 966 lip superimposed on, 73 in mastoid, 54 maxillary. See Maxillary sinus. pancreas in, 964 “pyloric star” seen through, 965 pylorus and, 935 spasm of, 963 ulceration of, 960, 961 Aorta arch of air–fluid level simulated by, 847 distortion of, 882 ectatic, 896 esophageal focal spiculation and, 947 esophageal indentation and, 945 lucency beneath, 869 mediastinal lipomatosis and, 855 pulmonary lesion simulated by, 838 pulmonary nodule simulated by, 838 with retroesophageal course, 894 trachea and, 830 coarctation of, 892 descending with paravertebral stripe, 861 straight back syndrome and, 882 subclavian artery and, 948 dilated ascending, 856 ectasia of, 832, 861 infrabronchial interface of, 861 knuckle of, 870 nipple shadow of, 892 pneumothorax simulated by, 810 pulmonary stripe of, 814, 854, 855 rupture of, 892, 895 shadow of, 848 tortuous, 869, 894 Apical abscess, 81 Apical ligament of odontoid, 114 Apical pneumothoraces, 5S–151 Apophyseal joint surface, 180 Apophyseal line in acromial apophysis, 288 irregularity of trochanteric, 506 Appendicitis, 938

Appendix air in, 938 intussusception of, 985 reduction and filling of, 985 sacroiliac joint and, 942 with subhepatic cecum, 981 Arcuate foramen, 138 Arcuate foramina atlantooccipital ligaments and, 98 for vertebral arteries, 93 Areae gastricae, 957 Areolar tissue, 814 Artery. See specific artery. Arthritis degenerative of the acetabula, 284 of the atlantoodontoid joint, 105 of the navicular, 692 in foot, 693 inflammatory simulated in fingers, 475 simulated in hand, 430 Arthrosis in congenital carpal fusion, 454 in lumbar spinous processes, 230 Articular process in laminar notch at C7, 181 simulated fracture of C2 and, 137 un-united ossification centers for, 3S–88, 156, 161 Articulating process developmental notch in of T12, 202 at L3 absence of inferior, 220 ossification centers for bilateral union failure of, 220 un-united, 219, 220 at L5 simulated spondylolysis of, 234 un-united secondary ossification centers for, 219 notches in superior at C6 and C7, 181 un-united apophysis of superior at L4, 219 Aryepiglottic folds, 770 Arytenoid calcification in cartilage of, 780, 782, 784 calcified, 785 variations in, 779 Ascariasis, 976, 978 Ascaris, 966 Ascites, 929 Aseptic necrosis of femoral head, 7S–193 of foot, 733 of humerus, 6S–167 of lunate, 438 of navicular, 439 Asthenic women, 878 Atelectasis costal cartilage calcification simulating, 826 epipericardial fat pad simulating, 886 hemidiaphragm superimposition simulating, 827 inferior vena cava shadow simulating, 901 soft arm tissue simulating, 836 thymus simulating, 907 Atlantoaxial joints, 123 Atlantooccipital ligament, 98 Atlantoodontoid joint, 105 Atlas anterior arch of accessory ossicle of, 106 midline closure defect in, 127 appearance of with head tilted, 125 assimilation of, 89 disparity of growth of, 110

Atlas (Continued) pseudonotch of, 110 transverse process of epitransverse process rising from, 92 paracondylar process articulation with, 88 Atresia, esophageal, 788 Atrophy, postobstructive, 1024 Auditory canal, 54 Avulsion fracture in foot, 644, 692 in forearm, 404, 405 in humerus, 357 in lumbar spine, 230 os subcalcis simulating, 678 in tibia, 7S–219 Avulsion injury simulated in ankle, 630 simulated in arm, 404 simulated in hip, 357 simulated in metatarsal, 715 simulated in phalanges, 470 Avulsive lesions, 263 Axillary artery calcification, 890 Axis vertebra, 110 Azygopulmonary recess, 873 Azygos arch azygos vein and, 816 behind trachea, 871 below manubrium, 852 posterior portion of, 872, 873 prominent, 888 Azygos fissure, 817, 818 Azygos knob, 872 Azygos lobe accessory fissure of, 818 azygos vein and, 815, 816 configuration of, 844 distended esophagus simulated by, 859 infiltrated simulated by, 844 with large subclavian artery, 891 mediastinal lipomatosis and, 858 pleural line configuration and, 815, 816 unusual, 817 Azygos vein arch of, 874, 881, 889 azygos fissure and, 817 catheter in, 874 configuration of, 815, 816 course of, 858 shadows of, 872 Azygous recess, 945 B Baastrup’s disease, 230 Balloon discs, 209 Basal foramina asymmetry of, 61 sphenoidal air cell simulating, 62 Basal ganglia calcification, 25 Basal pleural effusion, 62 Basipharyngeal canal in a 10-year-old, 1S–39 intersphenoidal synchondrosis simulation by, 64 Basisphenoid-basiocciput synchondrosis, 60, 61 Bathrocephaly, 1S–17, 39 Bertin’s columns, 1032 Biceps tendon, 294 Bicipital groove, 355, 356 Bifid interparietal bone, 40 Bifid spinous process of C5 and C6, 172 of L4, 229 neural foramen and, 162 Bile duct, 1003

Biliary tract, 1000–1005 Bipartite atlas vertebra, 127 Bladder, urinary, 1046–1051 colon displaced by, 981 configuration of, 1050 contour of, 1049 displacement of, 1043 distension of, 1038, 1040, 1047 elevation and elongation of, 1050 extraperitoneal herniation of, 1048 indentation in, 1051 levator ani muscles and, 1007 perivesical fat in, 1048 radiolucency in, 1051 sigmoid colon and, 994, 995 size of compared to abdomen, 1046 small bowel displaced by, 978, 981 trigone of, 1051 uterine impression on, 1049 uterus indentation of, 1007 visualization of, 1008 wall of, 1047 “Bladder ears,” 1048, 1049 Bone age acceleration, 422 Bone destruction cortical thinning of phalanges in, 478 lucency in first ribs and, 339 mastoid air cell and, 55 osteoporosis and, 637 radiolucency and, 398 rhomboid fossa and, 315 sphenoidal lesser wings and, 57 spinous processes and, 230 Bone dysplasia calcaneal ossification centers and, 667 cranium bifidum occultum and, 17 Bone formation in neonate, 522 of neoplasm, 527 periosteal new, 595 “tug” lesion representing, 518 Bone infarction, 510 Bone island acetabular, 4S–137 in fingers, 6S–189 in hand, 6S–179, 427 iliac, 261, 262 in lunate, 6S–179 in navicular, 6S–179, 6S–183 in ulna, 6S–172 Bone marrow, humeral, 372 Bone spiculation, 527 Bone tumor simulated by fibrous lesion, 525 Bony element accessory, in cervical spine, 93 of rib, 335 Bony erosion, 3S–72 Boomerang configuration, 23 Bowel. See also Colon. distended, 938 “double wall” sign of, 938 gas in destructive lesions simulated by, 239, 247 spondylolysis simulated by, 222 inflammatory disease of, 977 malrotation of, 979 small “cobblestone” terminal ileum of, 977 displacement of, 981 distension of, 1047 fluid-filled, 1009 gas in, 936 jejunum loops of, 973 lymphoid hyperplasia in, 977

Index Bowel (Continued) lymphoid tissue in, 977 malrotation of, 974 mucosal folds in, 978 mucosal pattern of, 976 pattern of, 975, 976 peristaltic contraction and, 976 ramification of, 974 simulation of, 986 stomach mucus and, 974 urinary bladder displacing, 978 valvulae conniventes of, 973 Bowing fracture, plastic, 608 “Bowling pin” configuration, 802, 804 Brachiocephalic vessels, 891 Breast air beneath, 929 air under, 809 axillary tail of, 806 carcinoma of femoral lucencies and, 521 pectoralis major muscle sternal insertion and, 807 compressed, 806 dense juvenile, 793 mediastinal pseudotumor of, 805, 808 shadow of, 809, 825 Breast implants, 808 Breech head, 40 Bronchiectasis, 939 Broncholith, 843 Bronchus arterial shadow on, 843 impression of on esophagus, 948 lower lobe continuation of, 860 shadow of, 877 tracheal, 845 Brow-up projection, 2S–48 Brunner’s gland hypertrophy, 966 “Bull’s-eye” lesion, 969 “Bumpy spine,” 3S–103 Bursa calcification of, 414 subdeltoid, 6S–167 Butterfly vertebra at C6, 167 congenital, 198 in lumbar spine, 212 at T6 and T7, 199 at T12, 200 Buttocks, fat in, 1006, 1007

C C1 vertebra absence of laminae of, 94 accessory bony elements and, 93 accessory ossicle in anterior to, 104 posterior to, 103 anterior arch of absence of, 88 closure defect in, 127 contour of, 103 ear lobe superimposed on, 96 fragmented, 107 fusion of, to odontoid process, 116 high position of, 101, 124 huge, 104 hypertrophied, 3S–71, 119 ligamentous calcification below, 107 ossicle of, 106, 107 ossicle fusion in, 3S–68 ossific nucleus for, 88 ossification absence in, 87 overdevelopment of, 118, 119

I-3

C1 vertebra (Continued) spurlike extension from, 3S–72 unfused, 63 anterior aspects of, 101 anterior process of accessory ossicles above, 104 huge, 104 longitudinal ligament calcification above, 105 normal position of, 100 C2 and facet between, 3S–77 instability of, 121 lesions between, 3S–77 odontoid hypoplasia and, 121 offsets of, 111 spinous processes of, 100 fracture of, 110 incorporation of into skull base, 89, 90 lateral masses of airway shadow on, 3S–69 assimilation of, 3S–64 asymmetry of, 3S–64, 3S–72 bilateral offsets of, 110 deformity of, 122 hemangioma of, 3S–68 hypoplastic, 111 normal, 109 occipital condyles and, 87 odontoid process and, 125, 126 os odontoideum simulation by, 120 space between dens and, 125 neural arch of absence of, 3S–64 absence of portion of, 3S–66 accessory ossicle and, 103 closure defects in, 94, 103 defects in, 97 development of, 3S–66, 95, 96 formation of, 3S–65 low position of, 101 sclerotic, 99 unfused, 3S–65, 3S–74 osseous pattern in, 3S–68 posterior arch of absence of, 94 articulation between skull base and, 3S–64, 91, 92 congenital absence of, 118 examples of, 3S–67 formation of, 95 osseous processes and, 103 overlapping shadows of, 3S–73, 128 posterior elements of, 99 pseudofractures of, 109 segmentation of, 90 skull base and, 3S–63 spinolaminar line absence in, 99 spondylolysis of, 97, 98 tipped axis of, 101 transverse process of elongated, 110 Mach bands and, 3S–74 uptilted neural arch of, 90 C2 vertebra anterior aspects of, 101 articular planes of, 123 articular process superimposed on, 137 asymmetry of, 123 C1 and facet between, 3S–77 instability of, 121 lesions between, 3S–77 odontoid hypoplasia and, 121 offsets of, 111 spinous processes of, 100

I-4

Index

C2 vertebra (Continued) C3 and articulation between, 139 fusion simulated in, 140 lesions between, 3S–77 nonsegmentation of, 139 ossicle between spinous processes of, 138 segmentation of, 142, 144 subluxation of differentiating from pseudo, 145 examples of, 145 on flexion, 3S–81 in pregnancy, 3S–82 pseudo, 144 clefts in anterior aspects of, 3S–79 coronal, 129, 130 laminar, 134 congenital block vertebrae in, 143 development of with ossicle, 137 hypoplasia of, 138 incomplete segmentation of, 90, 123 laminar closure defect in, 137 lateral masses of asymmetry of examples of, 3S–69, 3S–72 with odontoid and neural arches, 108 odontoid process deviation and, 3S–71 with other asymmetries, 123 bilateral offsets of, 110 elongated, 3S–73 osseous density representing, 3S–74 superimposition of on odontoid base, 117 lucency in, 141 Mach effect and, 3S–78 neural arch of contour of, 3S–75 double odontoid and, 3S–70 groove of, 3S–76 hangman’s fracture simulation at, 133 large, 108 rotation and, 3S–78 segmentation failure of, 3S–79 nonsegmentation of, 141 pedicles of, asymmetry of, 3S–79 pharyngeal soft tissue shadows and, 129 posterior arch of, 3S–67 posterior elements of, 152 pseudo “fat C2 sign,” 139 pseudofractures of, 131 ring shadows of, 130 rotation and, 150 segmentation failure of, 3S–70 soft tissue prominence at, 773 spina bifida occulta of, 3S–71 spinolaminar line failure at, 100 spinous processes of fissure in, 138 overgrowth of, 94 spondylolysis of, 3S–76, 135, 136 subluxation of, 3S–80, 146, 147 synchondrosis of ossification centers for, 129 target composite shadow in, 130 teeth shadows and, 3S–73 transverse process of, 3S–74, 3S–75 C3 vertebra accessory ossification centers for, 3S–84 articulating process pseudofracture of, 151 C2 and articulation between, 139 fusion simulated in, 140 lesions between, 3S–77 nonsegmentation of, 139 ossicle between spinous processes of, 138 segmentation of, 142, 144

C3 vertebra (Continued) subluxation of differentiating from pseudo, 145 examples of, 145 on flexion, 3S–81 in pregnancy, 3S–82 pseudo, 144 C4 and articulation between transverse processes of, 154 nonsegmentation of, 143, 178 spacing between spinous processes of, 152 subluxation of on flexion, 3S–81 in pregnancy, 3S–82 configuration of, 155 fracture simulated in, 3S–75 hypertrophy of and C2 hypoplasia, 138 incomplete segmentation of, 90, 123 lesion simulated at, 3S–88 neural arch of articulation with, 138 fracture simulated in, 3S–83, 149 segmentation failure of, 3S–79 nonsegmentation of, 3S–79, 141 normal, 3S–75 pseudofanning of with C4, 152 spina bifida occulta of, 3S–71 spinous process of, 3S–84 spondylolysis of, 3S–75, 136 subluxation with, 146, 147 wedged appearance of, 3S–86 wedging of, 155 C4 vertebra bifid spinous process of, 3S–86 C3 and nonsegmentation of, 143, 178 osseous articulation between transverse processes of, 154 spacing between spinous processes of, 152 subluxation of on flexion, 3S–81 in pregnancy, 3S–82 C5 and articulation between transverse processes of, 163 deviation of spinous processes of, 164 segmentation error at, 3S–95 jumped facet simulation at, 157 neural arch spondylolysis in, 153 nonsegmentation of, 3S–79 ossification centers for, 156 posterior arch of, 154 pseudofanning of with C3, 152 rotation and, 3S–88 subluxation of, 146, 147 wedged appearance of, 3S–86 C5 vertebra absence of pedicle at, 165, 166 articular process of, 3S–88 C4 and articulation between transverse processes of, 163 deviation of spinous processes of, 164 segmentation error at, 3S–95 C6 and apparent fusion of, 140 bifid spinous processes of, 172 block, with spina bifida, 177 ossicle between, 3S–94 segmentation failure of, 3S–96 soft tissue injury between, 3S–92 transverse processes of articulation between, 3S–91, 168, 169 elongated, 174

C5 vertebra (Continued) configurations of, 158 contour of, 3S–87, 159 facet fracture simulation at, 3S–91 laminae of, 3S–90 neural arch of, 180 omovertebral bone between T1 and, 185 ossification centers for, 156 short lamina of, 164 simulated fractures of, 158, 164 spinous processes of, 3S–92 spondylolysis of, 163 subluxation of, 146, 147 transverse process of elongated, 168 rib formation at, 3S–94 uncovertebral joint degeneration and, 182 wedged appearance of, 3S–86, 157, 158 C6 vertebra apophyseal joints of, 3S–97 articular process of, 161 C5 and apparent fusion of, 140 bifid spinous processes of, 172 block, with spina bifida, 177 ossicle between, 3S–94 segmentation failure of, 3S–96 soft tissue injury between, 3S–92 transverse processes of articulation between, 3S–91, 168, 169 elongated, 174 C7 and intervertebral disc narrowing at, 3S–98 nonsegmentation of, 3S–98 notches in articulating processes of, 181 contour defects at, 3S–87 enlargement of, 188 hemivertebra at, 167 increased density of, 175, 176 jumped facet simulation at, 167 lateral elements of, 3S–97 neural arch of, 180 spinolaminar line of failure at, 179 posterior tilt of, 3S–96 spinous processes of apophysis of, 174 bridge between, 184 elongated with block, 179 transverse process of, 3S–94, 174, 175 un-united ossification centers for, 156 C7 vertebra C6 and intervertebral disc narrowing at, 3S–98 nonsegmentation of, 3S–98 notches in articulating processes of, 181 foramen transversarium of, 186 notches in, 3S–96, 181 pedicle absence in, 185 posterior laminar line failure at, 187 rib and elongated transverse process at, 188 spina bifida of, 183, 184, 185 spinous processes of double with spina bifida, 184 with spina bifida occulta, 195 failure of apophyseal union of, 159, 186 transverse process of and ribs, 3S–94 Calcaneal cuboid coalition, 680 Calcaneus, 666–682, 7S–233–7S–235 accessory bone on lateral wall of, 643 apophysis of in adolescence, 675 appearance of, 684 closing, 7S–233

Calcaneus (Continued) failure of, 676 projection of tip of into soft tissues, 674 articulation of with talus and os trigonum, 7S–230 axial projections of, 7S–231 bilateral hypoplasia of, 666 bipartite ossification of, 694 cleft in, 7S–235, 667 contour alterations in, 7S–235 cuboid and, 650, 680 double ossification centers for, 668, 669 exostosis-like protrusion from, 682 fossa in, 678 fracture of, 705 fracture simulation in by calcaneus secundarius, 678 by sustentaculum tali, 679 lesion simulation in, 681 lucency in, 7S–234, 669 nutrient channel of, 678 os accessorium supracalcaneum and, 654 ossification centers for double, 667 locating, 675 secondary, 674, 676 ossification pattern of, 668 pseudocyst in, 672, 673 spurs on, 670 subluxation simulation in, 700 superior aspect of, with shelflike configuration, 676 trabeculation on cyst simulated by, 671 prominent, 681 trochlear process of, 676, 677 tuberosity of foramina in, 678 fossae in, 7S–234 irregularity of, 674, 675 simulated fracture of, 674 unfused secondary ossification center for, 675 variations in development of, 674 Calcaneus secundarius example of, 643 fracture simulation by, 678 large, 644 location of, 638 Calcific tendinitis of long head of biceps tendon, 294 of longus colli muscle, 106, 108 Calcified intervertebral disc, 211 Calculus biliary, 1003 coccyx ossification center simulating, 252, 941 coccyx simulating, 252 costal cartilage calcification simulating renal, 353, 940, 1023 stomach pylorus simulating, 1001 submaxillary gland, 782 urethral, 1055 Caldwell’s projection foramina rotunda in, 62 nasal passage mass simulation and, 2S–61 Calvaria, 3–18, 1S–1–1S–5 anterior fontanel bone of, 1S–3, 10, 11 congenital depressions of, 17 coronal sutures in, 13, 14 cranial hyperostosis in, 15 cranial vault compared to face, 1S–1 cranium bifidum occultum in, 17 depressions in, 18 digital markings in, 6

Index Calvaria (Continued) diploic patterns of in a child, 6 prominent but normal, 5, 7 in Waters’ projection, 5 diploic venous lakes in, 7 doughnut lesions in, 18 hair braids and, 4 intercranial hyperostosis in, 16 metastatic neoplasm in, 7 normal, 14 normal lucencies in aging, 14 occipital skin folds on, 1S–2 occipital thickening and, 16 occipital thinning and, 50 overlapping sutures in, 3 pacchionian depression in with area of density, 1S–3 deep but typical, 9 in the frontal bone, 9 lesion simulated by, 8 in the occipital bone, 9 pacchionian granulation in lucent depression of, 8 of skull vertex, 1S–3 parietal thickening and, 1S–4 parieto-occipital hyperostosis in, 1S–4 ponytail shadow on, 1S–2 radiolucency in, 14 sagittal suture serrations in, 5 scalp folds on, 4 sphenoparietal venous sinus groove in fracture simulation by, 8 prominent but normal, 7 squamosal suture in, 1S–4, 13 sutural sclerosis in, 1S–4 temporal thinning and, 1S–29 vascular channels in, 6 vascular grooves in, 1S–2 wormian bones in, 1S–3, 12 zygomaticofrontal suture in, 12 Cancellous bone cyst simulated by in fibula, 601 in rib ends, 346 in sacrum, 241 humeral tuberosity destruction simulated by, 362 lucency of, 305 lytic lesions simulated by, 318 of ulnar proximal ends, 393 Capital femoral epiphysis, slipped, 492 Capitate, 424–432, 6S–179–6S–180 accessory bone between lunate and, 6S–178 bone islands in, 427 fossae in, 428 fusion of to hamate, 430 joint between hamate and, 430 lucent cleft in, 428 os styloideum simulation by, 416 relationships to lunate, 431 vascular foramina in, 428 wrist fracture simulation by, 6S–180, 416 Capitellum epiphysis of, 382, 383 fossae above, 388 ossification of, 384 ossification center for, 6S–171 spurlike shadows and edge of, 387 Carcinoma annular, 988 femoral lucency and, 521 pectoralis major muscle insertion and, 807 Cardiac apex, 879 Cardiac cycle changes, 875, 876

Cardioesophageal junction, 950 Cardiomegaly, 877, 903, 904 Cardiophrenic angle, 883 Carotid artery calcification of, 24, 785, 890 thyroid cartilage calcification and, 780 transposition of during respiration, 774 Carotid groove, 1S–41 Carpal bones, 414–454, 6S–178–6S–185. See also specific bone. pathologic process simulation in, 6S–181 Carpal fusion bilateral, 432 of capitate and hamate, 430 of lunate and triquetrum, 431, 447 of navicular and trapezium, 438 between scaphoid, trapezium, and trapezoid, 438 of triquetrum and pisiform, 454 Carpal ossification centers, 422 Carpal tunnel projection os hamuli proprium in, 434 pathologic process simulation in, 6S–181 Carpal–metacarpal joints, 455 Cartilaginous femoral defect, 488 Cartilaginous tumor matrix, 510 Cartilago triticea, 784 Cathartic abuse, 986 Cecum enteroliths in, 940 in midabdomen, 980 mobile, 980, 984 mucosa of, 985 subhepatic, 938, 981 Cellule within frontal sinus, 75 Cephalohematoma, 1S–16 Cerebellar dentate nucleus calcification, 25 Cerebellar synchondrosis, 43 Cerebral palsy and patella, 7S–211 Cerebrospinal fluid space, 166 Cervical canal, 3S–62, 3S–63, 85, 86 Cervical cord lesion, 86 Cervical intervertebral disc, 3S–85 Cervical line subluxation, 147 Cervical spine, 84–188, 3S–62–3S–98. See also specific vertebra. accessory bony elements in, 93 accessory ossicle in anterior to C1, 104 posterior to C1, 103 apophyseal joints of simulated fusion of, 3S–85 surface notching of, 180 arcuate foramina and, 98 atlantoaxial joints in asymmetry of, 123 space margins of, 125 atlas of, 106, 127 bifid spinous process of, 162 block vertebrae in architectural defects and congenital, 143 incomplete segmentation of congenital, 141, 142 bony spur in, 93 calcific tendinitis simulated in, 108 cleft in neural arch of axis of, 93 craniovertebral dislocation and, 3S–63 curvature of, 146 dens of and lateral masses, 125 dens–C1 interval in, 102 disc herniations in, 158 “double odontoid” in, 3S–70 ear lobe superimposed on, 132 epitransverse process and, 92

I-5

I-6

Index

Cervical spine (Continued) facet of between C7 and T1, 187 degeneration of, 182 fracture simulation by, 3S–89, 3S–90, 3S–91 jumped simulation at C4 in, 157 foramen transversarium of asymmetric, 141 closure defect in, 186 lucency of, 140 juvenile vertebral bodies of in a 13-year-old, 155 normal wedge shape of, 155 lateral masses of asymmetry of, 121 dens and, 125 odontoid process and, 112 lesions simulated in, 183 ligamentum nuchae in, 3S–94 ligamentum nuchae ossification in, 173 limbus vertebrae in, 160 longitudinal ligament calcification in, 3S–68, 172 midodontoid process, 3S–73 neural canal in enlargement of, 86 infant vs. adult, 85 neural foramen of, 161 normal, 3S–81 notochordal remnants of at C2–C4, 152 at C2–C6, 3S–84 oblique atlantooccipital ligaments and, 98 occipital condyles in articulation between lateral masses of C1 and, 87 asymmetric development of, 123 occipital vertebra in, 89 occipital vertebral third condyle, 88, 89 odontoid process of accessory ossicle at tip of, 3S–69 anterior tilt of, 117 apical ligament of, 114 apparent fracture of, 127 asymmetry of, 116, 123 broad-based, 121 C2 lateral mass superimposition on, 117 clefts in, 118, 127 configuration of tip of, 123 congenital absence of, 118 development of base of, 122 discontinuity of, 120 fractures simulated in, 127 hypoplasia of, 3S–71, 120, 121 infantile, 121, 122 lateral masses of C1 and, 125, 126 Mach effect and, 3S–78, 128 mastoid overlapping and, 113 midline cleft in, 114 open-mouth view of, 127 ossicles around tip of, 124, 125 ossification and, 112 pointed anterior aspect of, 3S–72 posterior inclination of, 124 pseudofractures of, 126, 128 split simulated in, 126 subdental synchondrosis in, 117 synchondrosis of, 3S–70, 114, 115, 132 union failure of, 3S–70 os odontoideum in huge, 3S–71 and old fracture of, 3S–70 synchondrosis and, 119 with terminal segment, 120 ossicle simulated in, 105

Cervical spine (Continued) ossification centers for vertebrae of closing, 160 secondary, 159 paracondylar process and, 92 pinna of, air in, 96 posterior laminar line in, 102 pseudo “fat C2 sign,” 139 pyriform sinuses of, air in, 182 rib articulation in, 188 ring apophyses of the vertebrae of, 156 ringlike shadow in, 3S–95 sclerosis of, 3S–93 separation of from skull base, 84 short odontoid arch in, 108 “slipping” of vertebrae in, 148 soft tissue shadows on, 129 spinal ligament calcification in, 3S–67, 173 spinolaminar line of absence of at C1, 99 backward “displacement” of, 151 failure of at C2, 100 failure of at C6, 179 subluxation vs. pseudosubluxation and, 145 spinous processes of appearance of with head tilted, 125 overgrowth of at C2, 94 posterior base of simulating subluxation, 155 spacing between, 152 upturned, with flaring of, 170 variability of size and configuration of, 171 spondylolysis of in C1 of, 97, 98 subluxation of, 3S–80, 3S–81, 3S–82, 146, 147 transverse process of anterior tubercle of, 175 ossification centers for, 3S–89 shadows of, 176 uncinate apophysis of, 3S–88 uncinate process of, 131 uncovertebral process of, 132 un-united ossification centers for, 113, 156 vertebral segmentation in, 90, 123, 187 vertebral size variations in, 3S–92, 170, 171 vertebral underdevelopment in, 3S–95 Chest narrow, 863, 882 sagittal diameter of, 882 variation in contour of mid-, 348 wall of, 792–809 axilla and, 796, 806 breast axillary tail on, 806 breast compression and, 806 breast implants and, 808 breast shadows on, 793, 809 confluence of shadows on, 798 costal cartilage and calcification of, 797 isolated development of, 798 costoclavicular fascia calcification and, 797 curvilinear densities in, 793 extrapleural fat in, 801, 802 hair braid shadow on, 792 lung herniation on, 807 mammary mediastinal pseudotumor on, 805, 808 nipple shadow on, 807 parenchymal abnormalities in, 793, 797, 804 pectoral fold shadows on, 793, 806 pectoral muscle shadows on, 799, 800 pectoralis major muscle insertion in, 807 pneumothorax simulated in by pectoral skin folds, 806 by rib confluence, 805

Chest (Continued) by rib medullary cavity lucency, 805 by scapular spine shadow, 804 by skin folds, 793, 794, 795 by transverse process of T2, 805 ribs and, 798, 799 serratus anterior muscle shadow on, 802, 803, 804 soft tissue of, 808, 809 subcostal muscle shadows on, 798 supraclavicular fossa and, 798 Chiasmatic sulcus, 61 Cholecystectomy, 1002 Cholecystitis, 1001 Cholesteatoma, 54 Chondroid matrix of neoplasm, 553 Chondroid stripes, 276 Choroid plexus glomus calcification, 1S–7, 23 Clavicle, 312–321, 5S–149–5S–153 acromioclavicular joint of accessory ossicle in, 318 change in, 321 acromion and, 298, 320, 321 apophyses of, 313 companion shadows of, 796 coracoclavicular articulation in, 5S–152 coracoclavicular joint and, 317 coracoclavicular ligament and insertion of in a 6-year-old, 316 grooves for, 5S–151, 5S–152, 315 ossification of, 5S–153, 316 costoclavicular joint and, 317, 345 cupped articular surfaces of, 313 cupped juvenile configuration of, 313 distal ends of cancellous bone and, 318 configuration of, 319 displacement of, 321 duplication of anomaly of, 5S–153 example of, 318 partial, 319 flange on, 5S–153 fossae in, 316 fracture simulated in, 317, 318 irregularity of, 5S–153 position of in relation to acromion, 320 exostosis-like extension of, 5S–151 first rib and, 5S–152 foreshortening of, 321 fossae in, 839 malalignment of, 297 margins of, 5S–152 medial ends of accessory ossicle at, 5S–150 appearance of, 312, 313, 314 asymmetry of, 5S–149 failure of, 313 fracture simulated in, 5S–150 ossification centers for secondary, 5S–149, 313 un-united, 313 sclerotic, 313 nutrient canal of, 314 nutrient vessel in, 5S–150 ossicle on, 5S–153 rhomboid ligament and, 5S–151, 315 ribs and, 5S–160 scapular shadow on, 5S–152 shadow of, 798 shaft of, 5S–153 superimposition of on acromion, 321 supraclavicular nerve of, 5S–150, 314

Cleidocranial dysostosis, 12 Clinoid process anterior hidden, 67 orbital fissures and, 2S–44 ossicle at, 60 pneumatization of, 59, 68 calcification and intracranial, 20 ligamentous, 65 unusual dural, 1S–6 pneumatization of, 1S–35 extensive, 67 foramen-like shadows and, 63 posterior cleft in, 66 mushroom configuration of, 1S–40 sella turcica bridging in between anterior and middle, 65 and large, 66 well-defined middle, 64, 65 “Cobblestone” terminal ileum, 977 Coccygeoanal ligament, 1013 Coccyx, 250–252, 3S–121 absence of, 252 anteflexion of, 251 anterior angulation of, 250 bifid, 252 floating, 251 ischial apophysis and, 3S–121 junction of with last sacral segment, 251 ossification centers of, 252, 941 posterior position of, 251 scoliosis of, 3S–120, 252 Cochlear densities, 1S–32 “Cold” irregularity of distal femur, 527 of femoral metaphyses, 525 Colitis, ulcerative, 986 Collagen diseases, 483 Colliculus, 7S–223, 629 Colon, 979–999. See also Bowel. cecum in mobile, 980, 984 mucosa of, 985 displacement of, 981 diverticula of, 999 epiploic appendage attached to, 941 fat droplets in, 993 haustral pattern of, 985, 986 hepatic flexure of, 982, 991 ileocecal valves in, 983, 984 impression of on stomach, 964 ingested seeds in, 940 innominate grooves of, 992 interposition of, 930, 931, 932 intrathoracic migration of, 919 juvenile, 979 kidney displaced by, 981 “kissing” artifacts in, 998 lipomatoses in, 989, 990 lumbar spinous process and, 983 lymphoid follicles in, 992, 993 mucosal strands in, 997 overrotation of, 980 pelvic, 988 pressure defect on descending, 982 rectosigmoid, 995 sacral foramina projecting through, 998 sigmoid bladder pressure on, 994, 995 displacement of, 990 fat and, 989 pelvic mass simulated by, 1008

Index Colon (Continued) size of compared to abdomen, 979 small bowel simulation in, 986 sphincter of, 987, 988 splenic flexure of, 936 subhepatic cecum and, 981 superimposition of on stomach, 928 transverse, 972 urinary bladder displacing, 978 Colonic gas. See Bowel gas. Concha bullosa, 2S–60, 83 Condyle in anterior arch of C1, 88 femoral anterior surface of, 7S–208 contour of, 545 cruciate ligament calcification and, 552 excavation on, 532 flat appearance of, 545, 546 irregularities of in ossification of, 543 simulating osteochondritis, 7S–206, 541, 542 lateral articular surface of, 7S–208 cyst simulation in, 7S–204 irregularities of, 540 terminal sulcus of, 545 medial articular surface of, 547 lucent lesion in, 7S–204 ossification of, 7S–207, 542, 544 radiolucency in, 7S–207 popliteus tendon groove on, 547, 548, 549 fossae in, 1S–30 mandibular airway superimposition and, 79 bifid, 2S–58, 80 tongue shadow and, 78 occipital development of, 123 epitransverse process and, 92 lateral masses of C1 and, 87 odontoid hypoplasia and, 120 at skull base, 1S–38 third occipital vertebral, 88, 89 Condyloid canal, 1S–25 Congenital block vertebrae architectural defects and, 143 incomplete segmentation of, 141 Congenital malformation syndrome, 430 Cooper’s ligaments, 275, 1009 Coracobrachialis muscle, 369 Coracoclavicular articulation, 5S–152, 303 Coracoclavicular joint, 317 Coracoclavicular ligament grooves for insertion of, 5S–151, 5S–152, 315 insertion of, 316 ossification of, 5S–153, 316 Coracoid bone, 5S–140 Coracoid process of scapula apophysis of persistent primary, 5S–140 of tip of secondary, 287 un-united secondary, 291 during growth, 286 lucencies caused by, 295 ossification centers for nonunion of, 287 normal, 5S–139 premature appearance of, 285 secondary, 286 at synchondrosis of, 288

Coracoid process (Continued) projection of over glenoid, 295 as separate bones, 285 synchondrosis of, 5S–140 Cornrows, 5 Cornuate navicular, 647, 689, 690, 691 Coronal cleft vertebrae, 205 Coronal sutures at base of skull, 60 sclerosis of, 14 shadow of, 2S–60 simulated spread of, 13 vascular grooves in, 1S–28 Coronoid process in forearm long, 397 tendinous calcification at, 6S–174 tip of ossicle at, 6S–173, 396 ossification center for, 6S–173, 396 in mandible antrum tumor simulation and, 2S–48, 72 osteoma simulated by, 81 overlapping of, 80 pterygoid plates and, 2S–57 sinus air-fluid level simulation by, 2S–48 Corpora cavernosa, 1014, 1055 Cortical defect femoral, 500, 516, 517, 518 fibular, 614, 625 humeral, 6S–169, 370, 371 of metatarsal, 739 tibial benign, 614 juvenile benign examples of, 612, 613, 615 healed, 613 medial cortical irregularities and, 589 Cortical tissue invagination, 1032 Costal cartilage in absence of first ribs, 338 calcification of in a 28-year-old, 352 circular, 352 extensive, 5S–164 gallstones simulated by, 939 large, 343 lesion simulated by parenchymal, 797 sternal, 330, 331 linear, 353 lung abnormalities and, 826 nodular, 5S–158 renal calculus simulated by, 940, 1023 ring-shaped, 352 vascular calcification simulated by, 353 developmental variations in, 5S–158 extrapleural line and, 852 hepatic duct stones simulated by, 1005 hypertrophied, 343, 344 isolated development of, 798 overgrowth of on first rib, 339 un-united with first rib, 5S–156, 5S–157, 338 with second rib, 5S–157 Costal margin, 955, 956 Costochondral articulation degeneration, 347 Costochondral junction, 5S–159 Costoclavicular fascia calcification, 797 Costoclavicular joint, 317, 344 Costophrenic angle, 801, 811 Costophrenic sulcus, 1017

I-7

I-8

Index

Costovertebral articulation degeneration of, 197 enlargement of, 5S–162 hypertrophied, 3S–103 superimposition of on T12, 3S–104 Costovertebral junction, 344 Cowper’s glands, 1054 Cranial hyperostosis, 15 Cranial vault size, 1S–1, 1S–25 Craniosynostosis, 41 Craniovertebral dislocation, 3S–63 Craniovertebral separation, 84 Cranium bifidum occultum, 1S–5, 1S–9, 17, 26 Cricoid cartilage calcification, 782, 783, 784 Cricopharyngeus muscle, 943 Crista galli pneumatization, 2S–52, 76 Crohn’s disease, 977 Cruciate ligament calcification of posterior, 552 insertion of anterior tibial spine at, 580 undulating bone at, 583 Cuboid, 705–708, 7S–242 accessory bone of, 707 accessory ossicle adjacent to, 7S–230 calcaneus coalition with, 650, 680 calcaneus subluxation from, 700 cuneiform shadows and, 708 cysts simulated in, 706, 707 dense cortex of, 7S–242 fossae in, 707 fusion of with third cuneiform, 705 irregularities of of joint margins, 693 of posterior aspect, 705 metatarsal and, 7S–248 os peroneum and, 649 os tibiale externum and, 7S–239 osseous bridge between calcaneus and, 680 peroneus longus tendon groove on, 707, 708 Cuneiform, 694–704, 7S–241–7S–242 alignment of, 702 cuboid shadows and, 708 first bipartite, 698, 699 central densities within, 697 coalition of navicular with, 688 fossa on lateral aspect of, 704 osseous protuberance on, 699 ossification centers at tips of, 696 ossification irregularity in, 684, 696 shadows of metatarsal epiphysis and, 7S–241, 7S–242 spacing between second and, 701 supernumerary bone arising from, 699 fossa between second and third, 703 fusion between third metatarsal and lateral, 650, 701 irregular ossification of, 695 irregularity of, 694 medial surface groove on, 701 radiolucencies in and between, 704 shadows of, 700 spacing between first and second, 701 third contour alteration of, 703 fusion with cuboid and, 705 joint between fourth metatarsal and, 7S–242 tibialis anterior tendon groove on, 703 “Cupid’s bow” configuration of L4, 214 Cushing’s disease mediastinum and, 853 retrorectal space and, 991 Cyamella, 7S–209, 548, 549

Cyst calcaneal revealed by alternate projection, 672, 673 simulation of distinguishing from true, 672 by trabecular pattern, 671 in various projections, 673 Gartner duct, 1056 in proximal phalanges of first toes, 758 simulation of by acetabulum margin, 282 by base of unciform process, 432 in cuboids, 706, 707 by epipericardial fat pads, 883 by fibular head lucency, 599 in fifth metatarsal, 738 of first toes, 758 of greater humeral tuberosity, 363, 365 by humeral head, 357 in maxillary antrum, 2S–49 by metacarpal base lucency, 458 by proximal rib ends, 346 of sacrum, 241 by sustentaculum tali, 680 in talus, 656 by trabecular patterns on navicular, 442 by triquetrum ring lesions, 448 Cystic duct, 1002 Cystic lesion, femoral, 553 D Deltoid muscle fossae in clavicles and, 316 humeral cortical thickening under, 364 humeral insertion of in a 50-year-old, 365 bilateral view of, 366 MR image of axial, 367 T1-weighted, 368 resembling periostitis, 6S–170 shadow of soft tissue fold with, 365 Dens. See Odontoid process. Dens–C1 interval, 102 Dental crypt, 81, 82 Dentate nucleus of cerebellum, 25 Dextrocardia, 903, 908 Diaphragm, 914–921. See also Hemidiaphragm. antral, 961, 962 attachments of, 939 base height of, 929 colonic interposition and, 931 contours of, 928 depression of, 812 dome height of, 929 eventration of, 917, 920 fat and, 927 herniation of, 918, 919 liver and, 920 medial attachments of, 916 mucosal, 961 muscular slips of, 917 pleural calcification simulated by, 813 relative obliteration of, 814 rib superimposed on, 925 “scalloping” of, 915 shadows of, 927 spleen shadow displaced from, 934 sternal insertions of, 914 stomach and, 812 stomach gas bubble and, 920, 921 thymus and, 903 Diastatic fracture, 1S–18

Digital markings of the calvaria, 6 Diploic pattern, 5, 6, 7 Diploic venous lake in the lateral projection, 46 metastatic neoplasm simulated by, 7 Disc degeneration, 237 Diverticulum calyceal, 1026, 1027 esophageal, 789 gastric developmental, 953 with haustral pattern, 985 location of, 952 partial, 962, 963 simulation of by barium drip, 959 by pelvic phleboliths, 999 prostatic utricle simulating, 1052 “Dog ear” sign, 1009 Dorsal dislocation of ulna, 404 Dorsal kyphosis, 882 Dorsal patellar defect, 573, 574 Dorsal spine, 5S–154 Dorsum of hand, 415 Dorsum sellae lateral extensions of, 66 petroclinoid ligament calcification and, 66 pneumatization of, 1S–42 radiolucency of, 1S–40 “Double odontoid,” 3S–70 “Double wall” sign, 938 Doughnut lesion, 18, 32 Down syndrome ossification centers for manubrium in, 323 spondylolysis of C2 with, 135 Duct of Santorini, 1005 Duct of Wirsung, 1005 Ductus, 892 Duodenal loop, 967, 972 Duodenum, 966–973 ampulla of Vater in, 972 Brunner’s gland hypertrophy in, 966 bulb of air bubble in, 968, 969 air-filled, 966, 1001 antral mucosa prolapsed into, 966 fluid-filled, 933 food in, 966 gallstones simulated by, 1004 indentation on, 970 mucosal folds and, 968, 971 pancreatic rest in, 967 peristaltic contraction in, 970 suprarenal mass produced by, 1019 “bull’s-eye” lesion in, 969 common duct impression in, 971 displacement of, 973 gallbladder impression on, 972 inversion of, 967 lumen of, 968, 969 mucosal filling defects of, 969 peritoneal folds of, 970 stomach mucus and, 974 widening of loop of, 972 Duodenum inversum, 967 Dural sac in cervical spine, 86 thoracolumbar spinal canal and, 207 E Ear folded, 63

Ear (Continued) lobe of cervical spine and, 96, 132 mandible and, 2S–59 mass lesion simulated by, 769 nasopharynx and, 768 Ectasia aortic, 832, 861 of iliac artery, 1044 renal, 1033 Elbow, 383 “Elephant nose” pedicle, 223 Emissary channel, occipital, 1S–21 Emissary vein, mastoid, 1S–30 Emphysema basal pneumothorax with, 813 hair braids simulating, 791 intercostal lung bulging and, 824 Emphysematous cholecystitis, 1001 Emphysematous cystitis, 1048 Endocervical gland, 1056 Endocortical scalloping, 514 Enterolith, 252, 940 Enthesopathy below lesser trochanter, 7S–198 patellar, 577 tibial plateau spurs and, 581 Eosinophilic granuloma, 1S–3 Epicardial fat, 880 Epigastric mass, 334 Epiglottis shadow of in nasopharynx, 62 variations in appearance of, 770 Epipericardial fat pads extension of into interlobar fissures, 885, 886 pressure of and heart lucency, 888 size of, 887, 889 unusual configuration of, 888 variations in, 883, 884 Epiphyseal dislocation, 378 Epiphyseal fracture, 618 Epiphyseal line beaking of, 357 closed, 6S–169, 358 discontinuity of bone above, 378, 379 epiphyseal projections at, 404 femoral cortex irregularity above, 524 fibular, 7S–220 fracture simulation by in forearm, 6S–175 of lateral malleolus, 621 in metatarsals, 724 in phalanges, 473 lateral aspect of, 358 in metatarsal, 7S–241, 7S–242 normal, 357 osseous element in, 471 ossicle fusing at fibular, 622 radial, 6S–176 remnants of, 405 in rib, 5S–150 Epiphyseal plate angulation of in tibia, 619 closing of femoral stippling and, 553 spur after, 405 depression of, 620 extension of into epiphysis, 620 superimposed projection of, 408 Epiphyseal spur femoral, 493 metacarpal, 459 Epiploic appendage, 941, 942, 1010 Epipteric bones in a newborn, 12 Episternal bones, 326

Index Episternal process, 325 Epitransverse process, 92 Erector spinae, 259 Esophagitis, 947 Esophagogastric junction, 951 Esophagus, 943–948 air in example of, 871 lucency produced by, 869 in mid-, 870 swallowed, 828 atresia of, 788 bronchial impression on, 948 contractions of, 946 cricopharyngeus muscle in, 943 “curling” of, 946 displacement of, 894 diverticulum of, 789 extrinsic impression on, 945 focal spiculation of, 947 gas reflux in, 870 impression of on subclavian artery, 948 infantile, 946 lingual tonsil and, 943 mucosa of, 951, 952 pharyngeal mass in, 943 pleural stripe of, 822 postcricoid impression in, 944 in a postlaryngectomy patient, 945 presbyesophagus in, 946 reflection of, 869 shift of, 944 transverse striations of, 946, 947 venous indentation on, 945 Ethmoid bone, 76, 2S–52 crista galli in, 76 with frontal bone, 62 Ethmoidal air cell extension of into sphenoid sinus, 76 facial trauma and, 2S–44 frontal sinus cellule and, 75 in orbital floor, 76 overdevelopment of, 76 Ethmoidal cell, 2S–52, 76 Ethmoidal sinus, 76, 2S–52 Exostosis pisiform and, 76, 453 plantar ligament attachment site simulating, 682 simulation of in calcaneal plantar surface, 682 in calcaneal trochlear process, 676, 677 on clavicle, 5S–151 on third finger, 477 Expansile lesions of the sacrum, 245 Extensor muscle, 512 Extensor pollicis brevis tendon, 474 Extosis simulation of in mandible, 80 in phalanges, 477 Extrapleural fat, 801, 802 Extrapleural line, 852, 853 Extrapleural masses, 335 Extrapleural space, 858 Extrarenal collecting systems, 1025 Eyelid shadow, 2S–45, 70 F Fabella bifid, 600 head of, 601 variations in development of, 550

I-9

Facet joint, 201 Facial bones, 68–83, 2S–43–2S–61 Fallopian tubes, 1014, 1015 Falx cerebri calcification examples of, 22 frontal crest simulating, 20, 29 heavy, 1S–6 tentorium cerebelli and, 23 Fascia lata, 7S–198, 7S–199 Fat. See specific type. “Fat C2 sign,” pseudo, 139 Fat lines in hip, 492 Fat necrosis, 754 Fat pad in humeral joint posterior, 389 simulation of elevated, 388 between knee joint capsule and quadriceps tendon, 554 Fat stripe of chest wall, 309 prevertebral, 774 “Female prostate,” 1051 Femoral head, 486–493, 7S–192–7S–194 acetabular bone superimposed on, 490 acetabular lips of, 490 acetabular margin shadow on, 7S–193 acetabular nutrient vessel pit in, 4S–134, 276 acetabular ossification centers and, 277, 490 configuration variations in, 7S–193 cyamellae and, 7S–209 developmental variant in, 486 dislocation of, 487 fossa in, 489 fovea capitis of aseptic necrosis simulated by, 7S–193 fracture simulation by, 7S–193 large, 7S–192 normal asymmetry of, 489 osteochondritis dissecans simulated by, 489 hypertrophy and, 493 irregularity of, 487 meniscal ossicle near, 7S–209 morphology of, 7S–193 notch in, 488 ossification center for, 486, 487 overlap of with femoral neck, 497 plump, 492 popliteus grooves and, 7S–209 radiolucency in, 4S–136, 7S–192 slipped capital femoral epiphysis detection and, 492 spurs in, 493 vascular necrosis in, 7S–193 venous thrombus and, 1015 Femoral neck, 494–505, 7S–194–7S–197 double-contour effect of cortex of, 494 erosion of, 7S–194 greater trochanter shadow on, 7S–198 herniation pit in, 4S–127, 500, 501 hypertrophic changes at, 493 hypertrophic lipping in, 504 irregularities in, 7S–195, 494, 496 juvenile benign cortical defects in, 500 lucencies in, 496 osteoporotic femoral fracture and, 504 periostitis of, 7S–197 pseudolesion of in osteoporosis, 497 radiolucency of asymmetric, 7S–195 normal area of, 504 relative, 499 ringlike, 7S–196 ringlike, with sclerotic borders, 500

I-10

Index

Femoral neck (Continued) triangular, 497 ring lesions in, 4S–127 spurs on, 7S–194 striation of bone of, 505 thickening of, 502 trabecular radiolucencies in, 497 trabecular reinforcement in, 498, 503 upper margin of, poorly defined, 494, 495 “white line” of, 503 Femoral notch, 488, 494, 495 Femur. See also Femoral head; Femoral neck. condyles of articular surfaces of excrescences on, 7S–208 grooves of, 547 contour irregularity in, 545 cruciate ligament calcification and, 552 cyst simulation in, 7S–204 flat appearance of, 545, 546 irregularities of normal, 540 in ossification, 542, 543, 544 simulating osteochondritis, 7S–206, 541 lesion of anterior surface of, 7S–209 medial irregularity of, 541 lucent lesion in, 7S–204 ossification variant of, 7S–206 radiolucency in, 7S–206 popliteus tendon groove on, 547, 548, 549 terminal sulcus of lateral, 545 distal end of, 518–556, 7S–201–7S–210. See also Knee. cortical defects in, 525, 526, 527 cortical irregularities in above epiphyseal line, 524 on both sides of, 526 in cortex of, 532 in medial, 525, 526, 527 in posterior, 527, 528, 529, 530 cortical thickenings in, 519 defect in posterior, 527, 530, 531 epiphysis of accessory ossification center of, 7S–207 asymmetric development of, 535 cleft in, 536 irregular ossification of, 538 irregularities of, 7S–204, 538, 540 lucencies in, 539 radiolucent stripes in, 540 excavation on medial condyle of, 531 fat pad near, 554 fibrous lesion of, 525 gastrocnemius insertion into, 520 irregularities in, 523, 527 irregularity in ossification of, 523 lesion simulation in, 7S–201, 533 linea aspera in, 520 lucencies in, 521 medial irregularity of, 7S–202 metaphysis of irregularity of, 524 lucencies in, 539 ossification irregularity in, 536 radiolucencies in, 522 transverse lines of, 521, 522 nutrient foramen of, 521 nutrient vessel foramina of, 553 osseous excrescences along, 546 ossification variation in physis of, 575 posterior defect in, 7S–202, 7S–203 provisional calcification in, 522

Femur (Continued) radiolucency in anterior segment of, 552 in notch of, 554 residual posterior defects and, 7S–203 simulating cystic lesion on, 553 triangular, 520, 553 sclerosis of intercondylar fossae in, 551 stippled appearance of, 553 “tug” lesion of, 7S–201, 518, 519 epiphyses of capital, 486, 487 cleft of proximal, 487 medial collateral ligament calcification and, 518 medullary cavity of, 507, 529 physiologic bowing of, 533, 534, 535 shaft of, 507–518, 7S–198–7S–200 endocortical scalloping in, 514 fascia lata shadow on, 7S–198, 7S–199 iliotibial band shadow on, 7S–199 intramedullary densities of, 7S–200, 513 juvenile benign cortical defect in, 515, 517, 518 lesion in intertrochanteric region of, 499 linea aspera–pilaster complex of, 512 localized changes in, 509 longitudinal striations in, 517, 518 lucent fissures in, 515 lucent metaphyses of, 511 muscle near delineation of, 7S–200 interweaving of with fat, 7S–199 nutrient foramen in, 515 nutrient vascular channels of, 514 in osteoporosis, 511 osteosclerosis of premature, 507 physiologic anterior bowing of, 508 skin folds and, 505 soft tissue companion shadow of, 7S–200 trabeculation of, 510, 511 transverse lines in, 511 spurlike medial epiphysis of, 544 Ferguson’s view paraglenoidal sulci and, 258 sacroiliac joints and, 253, 254 Fetal packing, faulty, 17, 18 Fetal tortuosity, 1039 Fibrous lesion femoral, 525 humeral, 371 Fibula distal end of, 617–637, 7S–219–7S–226. See also Ankle. accessory bone at, 7S–219, 7S–220 accessory ossification centers for, 635 accessory soleus muscle and, 637 Achilles tendon shadow on, 7S–225, 635 cleft metaphyses in, 624 cortical bump in, 617 cortical defects in, 625 epiphyseal line in, 7S–220 epiphyseal offset in, 621 epiphyseal shadow of on talus, 7S–234 fossae in, 625, 626 lateral malleolus of epiphyseal line of, 621 foramen in, 635 fracture simulation of tip of, 633 os subfibulare at tip of, 632 ossification center in, accessory, 622 ossification center in, incomplete fusion of, 7S–224 ossification center in, secondary, 631 spurlike extension of, 7S–225

Fibula (Continued) malleolar lucency in, 635, 636 maturation between tibia and, 620 metaphyseal defects in, 625 metaphyseal depressions in, 619 os subfibulare of with deep fossa in, 633 fracture simulation by, 634 in oblique projection of, 633 os talotibiale in, 635 ossicle of, 7S–221, 622 osteoporosis in, 637 physeal closure at, 620 radiolucencies in epiphyses of, 7S–219 ringlike lesions of, 617 secondary ossification center in, 634 shadow overlapping in, 621 nutrient vascular channels of, 616 ossicle at superior end of, 598, 599 proximal ends of, 580–606, 7S–214–7S–217 accessory ossification center at, 598 configuration of, 600 cortex discontinuity simulation in, 600 epiphyseal lucency in, 599 flangelike expansion of neck of, 601 head of elongated configuration of, 600 lucency of, 599 ossicle at, 7S–217 simulated discontinuity of, 600 un-united accessory ossification center at, 600 interosseous crest prominence in, 606 metaphyses of, 601, 602 overlapping of on tibia, 594 short, 598 simulated dislocation of, 597 soleal line in, 604, 605 spur on, 604 tibial tubercle overlapping, 596 “tug” lesion in at soleus muscle of, 602, 604 in swimmers, 603 shaft of, 607–616, 7S–218–7S–219 cortical defect of, 614 cortical irregularities of, 610, 611 excrescences of proximal, 606 notchlike lesion in distal, 611 nutrient foramina of, 7S–219 physiologic bowing of, 607, 608, 609 Figure-of-three shape, 892 Filling defect bladder neoplasm and, 1051 in cecal mucosa, 985 circular mucosal, 969 in colon, 998 duodenal, 968 polypoid of duodenal bulb, 968, 969 esophagogastric junction as, 951 in stomach, 950 renal, 1027 tracheal, 843 in ureter, 1046 Finger, 469–484, 6S–188–6S–190. See also Phalanges; Thumb. clinodactyly of, 480 Mach effect and, 471 with oblique physis, 476 phalanges of accessory ossification centers for attempt to form in, 471, 473 avulsion injuries simulated by, 470 closing, 469

Finger (Continued) base of excrescence at, 474 fracture simulated in, 6S–188 notches in, 471, 475 spurlike projections from, 6S–188 bone island in head of, 6S–189 cortical thinning of shaft of, 478 distal attempted bifid, 482 contour of base of, 484 epiphyseal line of fracture simulation by, 473 osseous element in, 471 fifth metacarpal of fifth finger and proximal, 464 head irregularity in, 477 lucent fissures in epiphyses of, 473 middle anomalous development of, 479 hypoplastic, 476 osteosclerosis of, 477 pseudoepiphyses in, 472 short, of fifth finger, 463, 478 nutrient foramen of, 474, 477 ossicle of at base of index finger, 469 palmar aspects of, 476 ridges and projections of, 475 short middle, 463 soft-tissue calcification of, 6S–190 speckled densities in, 6S–189 supernumerary, 469 terminal configurations of, 481 sclerosis of, 483, 484 tuberosities of, 474 sclerotic, 6S–190 ungual tuft of, 6S–189 “Fish-mouth” configuration of clavicle, 319 Flank gas in, 936 mass in, 925 Flaring of spinous processes, 152, 170 Flexor digiti quanti muscle, 432 Flexor digitorum superficiale, 6S–174 “Floating coccyx,” 251 Focal destructive lesion in forearm, 398 Focal dural calcification, 21 Fontanel closing, 11 examples of, 10 fusing, 10 huge, 1S–3 mastoid, 44 normal, 10 in occipital projection, 41 parietal thinning and, 1S–15 remnants of, 11 in Towne’s projection, 11 Foot, 637–759, 7S–227–7S–250. See also specific bone; Toe. accessory bones of, 638, 643 additional phalanx in, 735 intercalary bone in, 637, 642 ossicles above middle of, 651 plantar fascia calcification in, 682 plantar ligament attachment site on, 682 tarsal of, 694, 695 unnamed element in, 652 vascular calcification in soft tissues of, 682 Foramen magnum abnormality of, simulated, 1S–27 fissures around, 1S–16 irregularities of, 1S–25, 1S–27

Index Foramen magnum (Continued) metopic suture and, 1S–20 occipital emissary vein above, 1S–21 Foramen of Bochdalek, 918, 919 Foramen ovale asymmetry of, 1S–37, 61 mandibular ramus and, 2S–58 with petroalar bar, 1S–37 with pterygospinous bar, 1S–38 Foramen spinosum asymmetry, 61 Foramen transversarium, 140, 141, 186 Foramina. See also specific type. basal asymmetry of, 61 sphenoidal air cell and, 62 of Bochdalek, 918, 919 calcaneal, 678 carotid, 1S–38 clinoid process pneumatization and, 63 for femoral nutrient vessels, 553 humeral, 6S–170 in ilia, 259 in maxillary antrum, 2S–48 mental, 2S–59 Morgagni’s, 907 in neural arch of lumbar vertebra, 224 for the occipital emissary vein, 45 optic, 1S–35 in parietal bone, 1S–13, 1S–14 in petrous ridges, 1S–33 sacral shadows of, 247 in scapula, 5S–148, 302 segmentation of C2 and C3 and, 142 sternal, 330 supraorbital, 2S–44 Foramina rotunda, 2S–52, 62 Forearm, 389–413, 6S–172–6S–177. See also Radius; Ulna. apophyses olecranon of, 391 bowing of, 401 calcification of, 401 coronoid process of tendinous calcification at, 6S–174 tip of ossicle at, 6S–173, 396 ossification center for, 396 distal portion of, 401–413, 6S–174–6S–177 epiphyseal line in radiolucent clefts adjacent to, 397 remnants of, 6S–175 spurlike epiphyseal projections at, 404 epiphysis of extension of into physis, 406 spurs on, 405 fossae in asymmetric, 6S–176 as insertion point of annular ligament, 397 interosseous membrane of, 402 interosseous ridges of, 399 metaphyses of irregularities of, 6S–174 spurs on, 402 olecranon of apophyses of, 389, 390 irregularities of, 392 ossification center for, 391 process of, 6S–172 spur at, 6S–172 patella cubiti and, 390 periostitis of in newborns, 399 proximal portion of, 389–401, 6S–172–6S–174 radioulnar joint of dislocation simulation of, 6S–175, 403

I-11

Forearm (Continued) fossae below, 407 ossicle of, 6S–176 radius of bone flanges in, 402 contour undulations in, 400 corpus triangulation and, 423 discordant closure of physis of, 407 epiphysis of cleft in, 409 fracture simulation in, 408 spurs in, 404 head of epiphysis of, cleft in, 394 epiphysis of, sclerotic appearance of, 393 spur arising from, 395 metaphyses of cleft in, 395 notches on, 394, 395 radiolucent clefts in, 397 spur arising from, 401 nutrient channel in, 400 spicules in epiphyseal cartilage of, 406 styloid process of, 409 tuberosity in, 398 ulna of accessory ossicle of, 410, 411 cancellous bone of, 393 cortical tunneling of, 400 deviation of, 443, 444, 445 epiphysis of cleft in, 408 unusual lucencies of, 410 foramina for nutrient vessels of, 392 fossa in, 403 long, 403 Madelung’s deformity and, 423 physis of discordant closure of, 407 metaphyseal extension into, 407 shaft curvature of, 404 spicules in epiphyseal cartilage of, 406 styloid processes of cleft epiphysis of, 408 large, 413 length and configuration of, 412 ossicle of, 412 ossification centers for, 411 ring shadow on, 413 trabeculations in shaft of, 391 ulna minus variation in, 401 ulna plus variation in, 403 Fossa supraspinata, 302 Fossae in acetabulum, 4S–138, 281, 282 in acromion process, 5S–143 calcaneal, 7S–234, 678 clavicular, 5S–150, 316, 839 condyloid, 1S–25, 1S–30 cranial, 1S–28 in cuboid, 707 femoral, 551 fibular developmental, 625 normal, 626 with os subfibulare, 633 on first cuneiform, 704 in forearm asymmetric, 6S–176 filling in of, 395 as insertion point of annular ligament, 397 unusual development of, 392 humeral, 377 ilial, 4S–124 mandibular, 2S–59

I-12

Index

Fossae (Continued) meningioma of, 1S–10 of metatarsal, 712, 725, 752 palpable developmental, 27 patellar bilateral appearance of, 578 comparison of with patellar elements, 571 normal, 579 size of, 570 in ribs, 340 in skull base, 1S–38 sphenoidal, 1S–36 submandibular, 2S–57 supraclavicular, 798 suprasternal, 788, 789 on talus, 661, 662 tibial, 7S–223, 584, 590 in toes, 7S–250 Fossae cribrosa, 243, 244 Fovea capitis, 7S–192, 7S–193, 489 Foveal lesion simulation, 281 Freiberg’s disease, 733 Frontal bone, 26–32, 1S–8–1S–12 anterior fossa of, 1S–10 cranium bifidum occultum in, 1S–9, 26 falx calcification simulated by, 29 focal dural calcification in, 1S–6 fossa in, 27 frontal accessory bone in, 27 hyperostosis of, 1S–27 hyperostosis frontalis interna in, 1S–12, 31, 32 junction of, with ethmoid bone, 62 metopic suture in fracture simulation by, 1S–8 serrations in, 26 nasofrontal suture in, 28 osteoporotic thinning in, 32 pneumatization of, 2S–49 in postmenopausal osteoporosis, 36 projections through occipital protuberance, 1S–10 sagittal suture groove, 1S–8 thinning of inner table of, 1S–12 unfused areas in, 1S–9 vascular channel in above sinuses, 29 examples of, 1S–11 fracture simulation by, 1S–10, 1S–11, 30 Frontal crest, 20, 29 Frontal sinus, 73–75, 2S–49–2S–52 aeration of incomplete, 2S–49 uneven, 2S–50 bowed septum of, 2S–52 discrete cellule within, 75 extension of cephalad, 2S–50 lateral, 2S–50 posterior, 2S–51 factitial clouding of, 2S–51 fossa pneumatization in, 75 intradiploic epidermoid simulation in, 74 lambdoidal suture superimposed on, 2S–51 lateral loculus of, 75 occipital protuberance and, 1S–26 overdevelopment of, 73 pseudo-mass in, 74 sclerotic nasofrontal suture of, 2S–51 sinusitis simulation in, 74 unilateral development of, 73

G Gallbladder, 972 Gallstone, 935, 939, 1004 Ganglion calcification of basal, 25 cyst of, 7S–216, 589 Gartner duct cyst, 1056 Gas reflux, 870 Gastric contents bronchiectasis simulated by, 939 rib lesion simulated by, 5S–163 Gastric diverticulum barium drip simulating, 959 developmental, 953 location of, 952 partial, 962, 963 Gastric erosion, 958 Gastric fundus, 934, 1019 Gastric mass, 951, 954 Gastric mucosa barium in folds of, 957 ectopic, 969 normal pattern of, 958 Gastrocnemius, 520 Gastroesophageal reflux, 946 Gastrointestinal tract, 943–1005 Genital tract, 1055–1056 Genitourinary tract, 1016–1056 Glenoid fossa apophysis of examples of, 5S–144, 294 ring, 5S–143, 292 cleft simulation in, 5S–140 coracoid process and, 295 defects in, 295 irregularities of, 6S–169 large shallow, 312 ossicle of at inferior aspect of, 293 at margin of, 5S–144, 294 and scapula, 292 secondary ossification centers for, 5S–144, 293 superimposition of, 188 Glomus calcification, 1S–7, 23 Glottis, 786, 787 Gluteus maximus fat accumulations in, 1007 ilial crest and, 259 Gonadal dysgenesis, 463 Great knob of Keats, 6S–187, 465, 466, 734 Great vessel calcification, 890, 891 Great vessels, 871–901 Growth arrest lines, 7S–218, 235 Growth lines, 3S–104 H Habenular commissure, 19 Hair braid shadow calcific thyroid mass simulated by, 790 interstitial air simulated by, 789 interstitial emphysema simulated by, 791 parenchymal abnormalities simulated by, 793, 826 sclerotic lesion simulated by, 4 on skull, 4 soft tissue appearance and, 792 Hamate, 432–435, 6S–180 absence of hook of, 434 capitate and fusion of to, 430 joint between, 430 overlapping shadows of, 6S–180 cleft in, 6S–180

Hamate (Continued) hamulus process of, 433 pisiform exostosis fused to, 453 pseudarthrosis between pisiform and, 454 ring shadows absent in, 434, 435 unciform process of cyst simulated by base of, 432 elongated, 432, 433 independent ossification of, 434 Hamstring muscle and “tug” lesions, 271 Hamulus process, 433 Hand, 414–484, 6S–178–6S–190. See also Carpal entries; Fingers; Metacarpals; Sesamoid. accessory ossicles of. See also specific ossicles. location of, 414 between lunate and triquetrum, 418 at radial styloid process, 415 calcified nodules in, 419 capitate of fracture simulation by, 416 os styloideum simulation by, 416 carpal coalitions in, 423, 424, 425 fissures between bones of, 447 intercalary bone in, 414 ivory epiphyses in, 479 joint space in, 6S–182, 430 triangulation of corpus of, 423 Hangman’s fracture simulation at C2 neural arch, 133 by spondylolysis, 135 Heart, 871–901 arm shadow on, 891 atrium of appendage of, 905 border of, 879 dilation of, 881 normal, 879 thymic extension to, 905 azygos elements in, 888, 889 bronchus shadow on, 877 cardiac apex in, 879 diaphragm depressed by, 812 displacement of, 920 double contour of border of, 876 ductus of bump in, 892 infundibulum of, 892 enlargement of, 881 epipericardial fat pads in extension of into interlobar fissures, 885, 886 pressure of and heart lucency, 888 size of, 887, 889 unusual configuration of, 888 variations in, 883, 884 flattening of, 882 great vessel calcification in, 890, 891 hemidiaphragm superimposed on, 827 lucency near, 869, 888 myocardial aneurysm of, 878 organic disease of, 882 pericardium of, 880, 881 pregnancy and, 881 pulmonary vessel shadow on, 877 shadow of, 901 size of comparative, 875 normal, 877 small, 878 variability in, 875, 876 stomach gas bubble and, 921 straight back syndrome and, 882 subclavian artery shadow on, 890

Heart (Continued) subepicardial fat line and, 880 Valsalva maneuver and, 876 Heavy metal poisoning, 522 Hemangioma, 3S–68 Hemarthrosis, 492 Hematoma, 475 Hematuria, 1028 Hemidiaphragm air–fluid level simulated beneath, 929 crus of, 916 loss of medial portion of, 833 stomach gas bubble and, 920 subdiaphragmatic fat under, 926 superimposition of, 827 Hemithorax, 800 Hemivertebra at C6, 167 partial, 211 Hepatic duct, 1002, 1005 Hepatic flexure, 982, 991 Hepatic shadow, 923 Hernia hiatal, 840, 951 internal, 973 thymus and, 907 Herniated disc, 3S–116 Herniated nucleus, 3S–115 Herniation pit in femoral neck, 4S–127 large, 501 subcortical, 500 “Herringbone” pattern on humerus, 371 Hiatal hernia, 840, 951 Hilar lip, 1031 Hill-Sachs deformity, 356 Hill-Sachs impaction fracture, 357 Hip. See also Acetabulum. in abduction, 486, 490 acetabular roof irregularity in, 488 capsule bulging in, 492 cyst simulation in, 282 fat lines in, 492 fovea capitis of, 489 ischial spine and, 4S–132 joint, 486–493, 7S–192–7S–194 in neutral position, 486, 490 Shenton’s line in, 491 “vacuum” phenomenon in, 491 Hoffa’s fat pad, 7S–210, 554 Humerus, 355–389, 6S–167–6S–171 aggressive osteoporosis in, 371, 372 articular surface of, 385, 386 aseptic necrosis of, 6S–167 bicipital groove in deep, 356 Hill-Sachs deformity simulated by, 356 shadow of, 6S–168, 355 bone rarefaction in, 378 capitellum of epiphysis of, 382, 383 ossification of, 384 ossification center for, 6S–171 spurlike shadows and, 387 coracobrachialis muscle insertion in, 369 cortex of defects in, 6S–169, 370, 371 notch on, 376 periostitis simulated by, 361 thickening of, 364, 366 deltoid muscle insertion in in a 50-year-old, 365 bilateral view of, 366

Index Humerus (Continued) MR image of axial, 367 T1-weighted, 368 resembling periostitis, 6S–170 destructive lesion simulated in, 378 distal portion of, 373–389, 6S–170–6S–171 epicondyles of flanges of, 373, 374 medial adult, 381 center of, 379 foramen above, 6S–170 ossification center for, dislocation simulated in, 381 ossification center for, fracture simulated in, 383 ossification center for, position of, 6S–173, 380 ossification centers for, 384, 385 epiphyseal line in beaking of, 357 closed, 358 discontinuity of bone above, 378, 379 lateral aspect of, 358 normal, 357 residua of closing, 6S–169 epiphyses of duplicated capital, 355 spurs in, 363 fatty bone marrow in, 372 foramen of, 377 fossae on anterior cortex of, 377 glenoid irregularities and, 6S–169 greater tuberosity of destruction of simulated in, 362 fracture of simulated in, 361 ossification centers for, 370 pseudocyst of, 363, 365 head of cystlike appearance of, 357 ossification centers for, 370 reverse Hill-Sachs impaction fracture simulated by, 357 “herringbone” trabecular pattern and, 371 intramedullary sclerosis of, 372 latissimus dorsi muscle insertion in, 369, 370 lesser tuberosity of, 363 lucency above joint of, 388 medial hematoma absent in, 381 medullary cavity of, 371 metaphyseal spurs in, 363, 364 notches in upper, 6S–169 olecranon fossa in perforated, 373 variations in appearance of, 377 olecranon process in, 378 ossicle of, 6S–169 ossification centers for, 381, 384 paratrochlear bones of, 386 pectoralis major muscle insertion in, 6S–170, 368 physiologic “periostitis” of, 373 posterior fat pad and, 389 proximal portion of, 355–373, 6S–167–6S–170 radiolucencies in metaphyses of, 388 rotator cuff and, 6S–167 sclerotic olecranon foramen of, 374 soft tissue folds and, 6S–171, 365 spurs on, 6S–169 subdeltoid bursa and, 6S–167 supracondylar process of, 374, 375 tendinous insertions in, 364 trochlea of appearance of, 383

Humerus (Continued) epiphysis of, 383, 387 ossification centers for, 379, 382 trough sign in, 356 tuberosity of, 6S–168 upper notches in, 358, 359, 360 Hydronephrosis, 1024, 1037, 1038 Hyoid bone, 778, 785 Hypercalcemia, 832 Hyperostosis. See also specific type. cranial, 15 of frontal bone, 1S–27 intracranial, 16 parieto-occipital, 1S–4 Hyperostosis corticalis generalisata, 1S–15 Hyperostosis frontalis interna asymmetric, 1S–12, 31 nebular, 1S–12 nodular benign, 31 with simulated doughnut lesion, 32 with simulated sequestrum, 1S–12 Hyperostosis interna, 53 Hyperostosis parietalis, 1S–15 Hyperphosphatemia, 832 Hypertrophy Brunner’s gland, 966 of C1 anterior arch, 119 of costal cartilage, 343, 344 of costovertebral articulations, 3S–103, 5S–162 diaphragmatic scalloping and, 915, 916 at femoral head, 493 at femoral neck, 504 iliopsoas, 1042, 1043 of interarticulating facets, 835 lipping in on distal femur, 546 of spine, 862 of pyloric stenosis, 963 spurring of adjacent to talonavicular joint, 657 vertebral, 833, 834, 835 ventricular, 879 Hypopituitarism, 24 Hypoplasia antral, 71 bilateral calcaneal, 666 of C1, 111 of C2, 138 in lumbar spine, 3S–106, 212, 213 of lunate, 425 of maxillary antrum, 2S–46 of nasal bone, 82 odontoid, 120, 121 in pedicle, 212 renal, 1024 of ribs, 335 scimitar vein and, 842 spondylolysis and, 136 of trapezoid, 435 Hyrtl’s foramen, 2S–55

I Ileocecal valves fatty infiltration of, 989 large, 983 with mobile cecum, 984 retrograde prolapse of, 984 Ileum, terminal cobblestone, 977 ileocecal valve and, 984 lymphoid hyperplasia of, 977 mucosal folds in, 978

I-13

I-14

Index

Iliac artery, 1044 Iliac bone island, 4S–127, 261, 262 Iliac bone ridge, 259 Iliac crest between gluteus maximus erector spinae, 4S–125, 259 irregularity of, 4S–123 shadow of, 221 Iliac fossae lucency, 258 Iliac rib, 264 Iliac spine healed avulsive lesions of, 4S–129 inferior, 4S–128 irregularities of, 263 ossification center for, 4S–128 Iliac vein, 1008, 1015 Iliac wings, 257 Iliacus muscle, 259 Ilial spur at sacroiliac joint, 245 Ilioischial line, 275 Iliolumbar ligament calcification lumbar spine and, 218, 237 sacrum and, 245 Iliopsoas hypertrophy, 1042, 1043 Iliopsoas muscle, 990, 1039 Iliosacral ligament “angel-wing” sacrum and, 239 calcification of, 3S–117, 239 Iliotibial band, 7S–199 Ilium, 257–264, 4S–123–4S–130 accessory elements in, 264 acetabular ossification centers and, 276 apophyses of caudad extensions of, 262 partial closure of, 263 bone islands in, 261, 262 “double” wings of, 257 flanges on, 4S–127 foramina in, 259 fossae in, 4S–124 linear density in, 259 muscle attachment spurring at, 260 notches in, 4S–125 nutrient artery grooves in, 4S–124, 257 ossification of, 4S–126, 260 pneumocyst of left, 258 preauricular sulcus in, 258 ringlike lesions of, 4S–130 sciatic foramina roofs in, 260 synchondrosis between ischium and closure of, 264 remnants of, 4S–130 Impaction fracture, 356 Inca bone examples of, 40 fracture simulation by, 1S–17 M-shaped, 40 Inflammatory bowel disease, 977 Infrabronchial descending aortic interface, 861 Infraorbital canal, 2S–48 Infraorbital foramina, 62 Infraorbital groove, 70 Infrascapular bone, 5S–146, 299 Infundibula, 1025 Infundibulum clawlike configuration of, 1025 of ductus, 892 figure-of-three shape and, 892 mucosal folds in, 1030 radiolucency in, 1033 renal papilla entering, 1027 shape of, 1033 tortuous, 1036

Inguinal ring bladder and, 1049 rectum and, 993 Innominate artery, 852 Innominate groove, 986, 992 Innominate vein, 852 Insufficiency fracture, 503 Intercalary bone in foot, 637, 642 in hand, 414 Interclinoid ligament calcification, 65 Intercostal vein, 892 Interlobar fissure caudal end of, 821 cephalic curvature of, 819 fat in, 856, 885, 886 Intermuscular incisurae, 1052, 1053 Internal auditory meatus, 1S–34, 56 Interosseous crest, 606 Interosseous membrane irregularities at insertion of, 402 ossification in, 7S–218, 611 Interparietal bone bifid, 40 cone-shaped, 41 normal, 39 paired, 41 persistent, 1S–17 rectangular, 1S–17 Intersphenoidal synchondrosis, 64 Interstitial emphysema, 791 Intervertebral discs loss of height of, 230 notochordal recession into, 3S–105 tall, 3S–106 Intervertebral foramina deformities of, 178 huge, 3S–111 widened, 166 Intestine. See Bowel; Colon. Intracranial calcification, 19–25, 1S–5–1S–8 of basal ganglia, 25 between clinoid processes, 20 in dentate nucleus of cerebellum, 25 dural, 1S–6 of falx cerebri examples of, 22 frontal crest simulating, 20 heavy, 1S–6 tentorium cerebelli and, 23 in glomus of choroid plexus, 1S–7, 23 of internal carotid arteries, 24 petroclinoid, 1S–5 pituitary stones as, 24, 25 types of focal dural, 1S–6, 21 habenular commissure, 19 os supra petrosum of Meckel, 1S–6, 20 petroclinoid ligament, 19, 20, 22 pineal gland, 23 tentorium cerebelli, 22 Intracranial hyperostosis, 16 Intracranial pressure, 6, 13 Intradiploic epidermoid, 74 Intraluminal lesion, 968 Intraparietal suture, 33 Intraperitoneal fluid, 1009 Intraspinal lesion, 3S–96 Intratracheal mass, 872 Intrauterine stress, 522 Intravertebral disc herniation, 231 Ischial apophysis closed, 270 coccyx and, 3S–121

Ischial apophysis (Continued) en face view of, 4S–131, 269 fused, 271 normal, 269 prominent, 270 remnant of, 4S–131 “tug” lesions and, 271 unusual presentation of, 270 Ischial spine, 4S–132 Ischial tuberosity, 4S–133, 271 Ischiopubic junction notch, 272 Ischiopubic synchondrosis accessory ossification centers for, 268 closure of, 267, 268, 269 open, 268 Ischium, 265–275, 4S–131–4S–133 bone islands in, 281 Cooper’s ligaments in, 275 ischial spine superimposition and, 4S–132 ischial tuberosity edge and, 271 medial protrusion of, 265 ossification of irregularities of, 4S–131, 271 rider’s bone type of, 275 radiolucencies in, 274 shadow of, 4S–137 synchondrosis between ilium and, 4S–130, 264 Isolette cover radiolucencies, 824 J Jefferson’s burst fracture, 111 Joint capsule insertion, 503 Joint cavity, 343 Joint disease acetabular sclerosis and, 284 humeral spurs simulating, 6S–169 tibial plateau spurs and absence of, 581, 582 Joint space apparent loss of in hand, 430 atlantoaxial, 125 radiographic, 299 widening of in foot, 733 Jugular foramina, 62 Jumped facet, simulated, 157, 167 K Keats great knob of, 465, 466 lesser knob of, 460 Kerckring’s ossicle, 38 Kidney, 1016–1038 appearance of, 1022 backflow and, 1033 Bertin’s columns in, 1032 bladder and, 1038 calculus in, 353, 940, 1023 calyces of accessory, 1026 dilated, 1024 diverticulum of, 1026, 1027 filling of, 1031 filling defect simulated by, 1027 folds of, 1030 miniature, 1026 mucosal folds in, 1030 multiplicity of, 1023 upper pole, 1029 collecting system of, 1032, 1034, 1036 contour of, 1022 dilation of, 1038

Kidney (Continued) disease of, 1025 displacement of, 981, 1022 duodenal displacement by, 973 duplication variant and size of, 1022 extrarenal pelvis of, 1037 fetal lobulation of, 1018 hilus of, 1031, 1034 infundibula in, 1025, 1033, 1036 intrathoracic migration of, 918, 919 left bump in, 1017 calyceal folds of, 1030 dromedary, 1019 low-lying, 1017 megacalyces of, 1024, 1025 size of, compared to right, 1022 splenic impression on, 1017 medullary sponge, 1033 papillae of aberrant, 1027, 1028 malformation of, 1024 tubular blush and, 1033 pelvic, 1020 pelvic emptying in duplex, 1038 pelvic lipomatosis in, 1033 right appearance of, 1017 bump in, 1018 detailed view of, 1024 extrarenal pelvis of, 1037 hepatic impression on, 1018 megacalyces of, 1024, 1025 outline variations of, 1021 ptotic, 1021 rotation of, 1017 size of, compared to left, 1022 variation in outline of, 1018 rotation of, 1022 saddle reflux in, 1038 superior pole defect in, 1034 suprahilar region of, 1031 tumor of, simulated by spleen, 1020 uncus of, 1031 unicalyx, 1023 “yo-yo” effect in, 1038 “Kissing” artifacts rectal, 996, 997 in stomach, 959 in transverse colon, 998 Kissing spinous processes, 230 Knee. See also Patella. articular cartilage in, 7S–210 compartments of lateral, 7S–210 medial, 7S–210, 555, 556 fabella and, 550 fat pad between quadriceps tendon and, 554 femoral condylar irregularities and, 540, 541 knocked, 533, 534, 535 meniscal ossicle near, 551 misleading shadows in projections of, 540 ossification irregularity in, 537 transverse intermeniscal ligament and, 552 “vacuum” phenomenon in, 555 wedging of ossification centers for, 534 Knock-knee, 533, 534, 535 Kohler’s disease, 685 Kump’s hump, 406, 586, 619 Kyphosis dorsal, 882 thoracolumbar, 193 vertebral magnification caused by, 3S–100

Index L L1 vertebra asymmetric development of, 215 bulbous configuration of, 228 spina bifida occulta of, 3S–101 spinous process of, 3S–114 styloid process of, 213 transverse process of absence of, 214 un-united, 3S–107, 215 unconnected ribs at, 215 wedged appearance of, 227 L2 vertebra rib formation at, 3S–108 spina bifida occulta of, 3S–101 spondylolysis of, 221, 222 wedged appearance of, 227 L3 vertebra absence of left pedicle of, 224 articulating process of, 219, 220 pseudospondylolysis at, 221 segmentation of, 3S–111 transverse process of cross-section of, 217 L4 and articulation between, 3S–107, 216 bridge between, 216 pseudarthrosis between, 217 ptotic, 215 L4 vertebra articulating process of ossification center fusion failure of, 3S–108 un-united apophysis of, 219 “Cupid’s bow” configuration of, 214 facets of cleft in, 3S–110 large, 234 mass simulation by, 3S–109 lamina of, 225 lucencies in, 3S–110 mammillary process apophyses in, 219 pedicle of absence of, 3S–111 destruction simulation in, 226 pseudospondylolysis at, 221 radiolucency within, 210 scoliosis and, 226 segmentation of, 3S–111 spinous processes of, 3S–113, 229 styloid processes of, 214 transverse processes of absence of, 216 articulation between L5 and, 235 cephalad-directed, 217 L3 and, 3S–107 articulation between, 216 bridge between, 216 pseudarthrosis between, 217 L5 vertebra articulating process of, 219 articulation of between sacrum and, 3S–115, 237 between transverse processes, 235 facets of large, 234 mass simulation by, 3S–109 laminar absence of, 3S–112 neural arch of, 3S–115 notochordal remnants in, 210 retrospondylolisthesis of, 233 “ribs” at, 235 ring apophysis of, 232 sacralization of, 236

L5 vertebra (Continued) secondary ossification center for, 231 spina bifida occulta of, 3S–115 spinous process of, 3S–114 spondylolisthesis of “Napoleon’s hat sign” of, 238 reverse, 233 spondylolysis of facet cleft in L4 and, 3S–110 simulation of, 3S–109, 234 transverse process of, 3S–108 wedged appearance of, 233 Lacunar skull, 6 Lambdoid suture, 44 Lambdoidal suture defects in, 44 fracture simulation by, 1S–18 sclerotic, 2S–51 Lamina absence of in C1, 94 in L4, 225 in L5, 3S–112 bone thickening at, 3S–103 of cricoid cartilage, 782, 783 facets and, 3S–90 Laminar line posterior dens–C1 interval and, 102 failure of at C7, 187 Laryngectomy, 945 Larynx calcification of, 783 pharyngeal mass and, 943 ventricle of, 786 Latissimus dorsi muscle, 369, 370 Leg, 580–637, 7S–214–7S–226 Lesser knob of Keats, 460 Levator ani muscle, 996, 1006, 1007 Ligament. See specific type. Ligamentous calcification below anterior arch of C1, 107 between T1 and rib, 336 Ligamentum arteriosum, 893 Ligamentum nuchae calcification of, 3S–94, 50 ossified, 173 Ligamentum teres of liver, 937 Limbus vertebra at C5 and C6, 156 at T10, 197 un-united, 231 Linea aspera, 520 Linea aspera–pilaster complex, 512 Lingual tonsil, 943 Lingular fissure, 818 Lip shadow of on cervical spine, 129 on mandible, 763 summation, 764 superimposition of on antra, 73 Lipohemarthrosis, 554 Lipomatosis ileocecal, 989 mediastinal aortic pulmonary stripe and, 855 examples of, 858 extensive, 853 paraspinal, 864 progressive, 854 pelvic, 989, 990, 1033 Lisfranc dislocation, 702

I-15

I-16

Index

Liver, 1000–1005 colonic interposition between diaphragm and, 931 ducts of bile, 1003 common, 1001, 1002, 1004 cystic, 1002, 1004 hepatic, 1005 Santorini’s, 1005 Wirsung’s, 1005 fat around, 929, 930 gas bubble of stomach and, 934, 953 gastric impressions related to, 953 hepatic duct of, 1002 hepatic flexure and, 982 interposed between stomach and diaphragm, 920 pancreatic duct of, 1004 pseudocalculus sign in, 1003, 1004 Riedel’s lobe of, 937, 1000, 1001 size of compared to abdomen, 1000 Longitudinal ligament calcification, 105, 172 Longus colli muscle calcific tendinitis, 106, 108 Lordosis, 230 Lordotic curve, 149 Lower extremity, 485–759, 7S–191–7S–250 Lucency abdominal, 927 above acetabula, 283 of acetabula, 280, 281 adenoidal, 766 in aging calvaria, 14 around heart, 869 beneath aortic arch, 869 butterfly vertebra and, 200 in calcaneus, 677 of capitate, 428 cortical, 371, 573 of epiphyseal fissures in phalanges, 473 of epiploic appendage, 942 femoral breast cancer and, 521 cortical defect and, 517 epiphyseal, 539 fissures of, 515 head lesion and, 489, 490 metaphyseal normal developmental, 539 in osteoporosis, 511 in femoral neck, 496, 497 fibular, 599 in first ribs, 339 of foot, 740 of foramen transversarium, 140, 141 under heart, 888 humeral above joint, 388 cartilage envelope and, 386 of trochlea epiphysis, 387 of iliac fossae, 258 irregular in calcaneus, 669 in lumbar spine, 3S–110 malleolar, 635, 636 mandibular, 2S–59 of maxillary antrum, 2S–47 between maxillary incisors, 126 in mediastinum, 846 in metacarpals, 458 in metatarsal, 738 in occipital bone, 1S–25, 1S–30, 48 in parietal bones, 34 patellar, 7S–213 of psoas muscle, 923, 924 pulmonary, 868, 869 of pylorus, 935

Lucency (Continued) of rib medullary cavity, 805 in rib tubercles, 346 in sacrum, 3S–118 in scapular neck, 295, 305, 306 in shoulder joint, 310 of subepicardial fat line, 880 in temporal bone, 53 tibial, 7S–222, 583 of ulnar epiphyses, 410 Lumbar bone island, 205, 207 Lumbar lordosis, 238 Lumbar spine, 204–237, 3S–104–3S–116. See also specific vertebrae. articulations with sacrum and, 236 asymmetry of in facets of, 223 in transverse processes of, 216 “balloon” discs in, 209 “bone in bone” appearance of, 204 bone island in, 205, 207 defects of, 229 end-plates of contour of superior, 211 depressions in, 3S–105 growth arrest lines in, 235 growth lines in, 3S–104 hemivertebra in, 211 iliolumbar ligament calcification in, 218, 237 nerve roots in, 3S–116 neural arch of anomalous foramen in, 224 incomplete closure of, 211 notochordal remnants of, 209, 210 pedicles in duplication of, 208 “elephant nose,” 223 flat, 208 “pig snout,” 222 size of, 3S–105 thin, 208 posterior “stepping” of, 232 retrosomal cleft on, 206 scalloping of posterior aspects of, 226 sclerotic band in, 206 spinous processes of Baastrup’s disease in, 230 closing apophyses of, 3S–113 colonic mass simulated by, 983 degenerative changes in, 230 sclerotic, 230 supraspinous ligament of, 230 transverse processes of absence of congenital, 216 at L1, 214 psoas muscle shadow and, 214 “two-eyed Scotty dog” in, 223 vascular channels of, 205 vertebrae in butterfly, 212 coronal cleft, 205 hypoplastic, 3S–106, 212, 213 long, 227 osseous bridge joining L1, L2, and L3, 218 oversized, 227 spurred osteoporotic, 228 Lumbosacral disc, 237 Lumbosacral nerve, 3S–116 Lunate, 424–432, 6S–179–6S–180 accessory bone between capitate and, 6S–178 aseptic necrosis of, 438 bipartite, 424 bone islands in, 6S–179, 427 hypoplastic, 425

Lunate (Continued) instability of, 426 interval between navicular and, 444, 445 relationships to capitate, 431 triquetrum and accessory osseous element between, 449 coalition of abortive, 425 incomplete, 447 fusion of, 6S–185, 431, 447 underdevelopment of, 445 vascular foramina in, 6S–179, 428 volar tilt of, 426 Lung, 824–845. See also Pulmonary entries. air trapped in, 828 air–fluid level simulated in, 798 apex of bulla or cavity in, 798 herniation of, 790 opacities of, 838 azygos lobe and, 844 breast shadows on, 825 bronchiectasis in, 939 cartilaginous ring calcification and, 832 consolidation of, 809, 825, 833 costal cartilage calcification and, 826 epipericardial fat pads in, 885 fat extension over, 858 hair braid shadow on, 826 hazy densities in, 800 hemidiaphragm and heart and, 827 herniation of, 807 hiatal hernia and, 840 hypertrophic spur in, 833, 834, 835 intercostal bulging of, 824 interface of, 823 interspaces of, 824 isolette cover radiolucencies and, 824 kidney appearance and, 1017 lesions in, 800 cavitary calcified costal cartilage simulating, 352, 797 clavicular fossa simulating, 839 rhomboid fossae simulating, 315 transverse processes simulating, 5S–164 vascular shadows simulating, 837 infrascapular bone simulating, 5S–146 nodular nipple shadow simulating, 836 rib ends simulating, 351 transverse process simulating, 351, 833, 835 vascular structures simulating, 838 lucency in, 868, 869 margins of posterior, 936 nipple shadow on, 836 nodular shadows in, 834 parasternal stripe and, 850 parenchymal opacity and, 827 pectoral muscle shadows on, 824 retrocardiac space in, 840 retrosternal line and, 848, 849, 850 scapulae superimposed on, 832 scapular shadows on, 824 scapular spine overlapping, 804 scimitar vein in, 842 skin lesion shadows on, 837 soft arm tissue and, 836 subclavian artery shadows on, 839 transverse processes and, 833 vascular configuration in, 840 vascular confluence in, 841, 842 vascular prominence in, 839 Lymph node, mediastinal, 867, 868

Lymphoid follicle, 985, 992, 993 Lymphoid hyperplasia, 969, 977 Lymphoid tissue lingual tonsil and, 943 in small bowel, 977 tongue surface and, 765 Lytic lesions iliac fossae lucency and, 258 of the sacrum, 3S–118, 243 scapula radiolucency and, 296 simulation of by distal ends of clavicles, 318 by humeral rarefaction of bone, 378 by humeral tuberosity, 6S–168 by hypoplastic vertebra, 3S–106

M Mach effect in abdomen, 925 around heart, 869 cervical intervertebral disc and, 3S–85 cervical spine and, 3S–74 in fingers, 471 from lip shadows, 129 in lower leg, 7S–221 navicular and, 6S–182 odontoid process and, 3S–73, 3S–78, 128 from tongue shadows, 113 Madelung’s deformity, 423 Malignancy femoral defect simulating, 525 humerus notches simulating, 359 pelvic density simulating, 1010 Malleolus accessory skeletal elements surrounding, 637 clefts in, 623 lateral accessory ossification center for, 635 Achilles tendon shadow on, 635 epiphyseal line of, 621 foramen in, 635 lucency in, 635 os subfibulare at tip of, 632 ossicle between talus and, 627 ossification center for incomplete fusion of, 7S–224 secondary, 631 spurlike extension of, 7S–225 talus overlapped by, 659 trabeculations on, 633 medial accessory ossification center for, 629 bifid, 7S–223 bony flanges on, 630 closure failure in, 623 colliculus of, 629 fracture simulation of, 7S–223 lucency in, 7S–222, 636 ossicle of, 7S–222 ossification of, 627, 628 ossification center for accessory, 7S–222 secondary, 627, 628, 638 separate, 629 radiolucency in, 628 os subtibiale and, 629 posterior accessory ossification center for, 631 articular surface of density in, 631 fossa on, 7S–223 cortex undulations in, 7S–224 Mach effect and, 7S–221

Index Mammary mediastinal pseudotumor, 805, 808 Mammillary process persistent apophysis of at L4, 219 “two-eyed Scotty dog” and, 223 Mandible, 78–82, 2S–56–2S–59 angles of, 80 ascending ramus of, 2S–58, 2S–59, 80 condyle of airway superimposition and, 79 bifid, 2S–58, 80 tongue shadow and, 78 coronoid process of antrum tumor simulation and, 2S–48, 72 nasal passage and, 764 osteoma simulated by, 81 sinuses and, 2S–48 dental crypt in, 81, 82 destructive lesion simulated in, 2S–58 earlobe and, 2S–59 foramen ovale and, 2S–58 fossae in, 2S–57, 2S–59 geniohyoid tubercle of, 81 lip shadows on, 763 mass below, 765 masseter muscles and, 80 mental foramina in, 2S–59, 81 nerve entry point in, 80 pharyngeal air shadows and, 2S–56, 79 pterygoid plates of, 2S–57 temporomandibular ligament insertion in, 2S–56 Mandibular canal, 2S–57, 2S–59 Mandibular condyle, 80, 2S–58 Mandibular nerve, 80 Manubrium azygos arch and, 852 mediastinal mass simulated by, 326, 327, 852 ossification centers for delayed appearance of, 322 double, 5S–154, 323 sclerotic borders of, 327 soft tissue mass simulated by, 809 subclavian artery shadow and, 890 superimposition of, 200 Masseter muscle, 80 Mastoid, 54–56, 1S–30 air cells in, 1S–30, 55, 56 asymmetric development of, 1S–30 auditory canal air in, 54 emissary vein in, 1S–30, 56 large antrum in, 54 ossicle simulated by, 105 overlapping of, 113 pneumatization of, 55 sigmoid sinus in, 56 Mastoid fontanel indicators, 44 Maxillary incisor shadows, 126 Maxillary molar, impacted, 72 Maxillary sinus, 71–73, 2S–46–2S–49 air–fluid level simulated in, 2S–48 compartmented, 2S–47 development of, 2S–47 excrescence in, 2S–48 floor density in, 72 hypoplasia of, 2S–46, 71 lateral wall thickening in, 2S–48 loculation of, 2S–46, 2S–47, 71 mandibular coronoid process and, 2S–48, 72 nares in, 73 superior alveolar canal and, 72 upper lip superimposition on, 73 Waters’ projection and, 2S–49 Maxillary sinusitis, 70

I-17

Meckel, os supra petrosum of, 1S–6, 20 Medial border of C1, 109 of thoracolumbar junction, 195 Mediastinal line, 823 Mediastinal pleura, 814 Mediastinal stripe, 823 Mediastinum, 846–871 air–fluid level simulated in, 847 azygos elements in, 858, 859 configuration alterations in, 854 density in, 848 extrapleural line and, 852 fat of along mediastinal border, 857 ascending aorta simulated by, 856 extension of, 856, 858 increase of, 857 mediastinal configuration and, 853, 854 paraspinous, 864, 865 retrosternal line and, 848, 849 gas in, 870 interlobar fissure of, 856 linear densities in, 855 lipomatosis of aortic pulmonary stripe and, 855 examples of, 858 extensive, 853 paraspinal, 864 progressive, 854 lymph node of, 867, 868 mass simulated in in adults, 861 by aortic arch, 894 by arm fold, 846 by articulation between T11 and T12, 202 by azygos vein, 874 by breast axillary tail, 806 by calcified costal cartilage, 797 by extrapleural line, 852, 853 in infants, 860 by juvenile breast density, 805, 808 by manubrium, 326, 327, 852 by osteophyte, 196 by scapula, 846 by sternal ossification centers, 852 outline of, 891 paramediastinal stripe in, 861 paraspinous soft tissue shadows in, 865 parasternal stripe and, 850 paravertebral soft tissue in, 866, 867 paravertebral stripe in examples of, 862 fat displacing, 864 in narrow chest, 863 normal, 861 psoas muscle and, 865, 866 radiolucencies in, 851 residual thymus and, 911 retrosternal line and, 848, 849 rounded densities overlying, 796 shifting of, 831 sternal ossification centers and, 852 thymus and, 901, 908 widening of produced by filming in expiration, 895 produced by lordotic projection, 846 produced by mediastinal fat, 853 produced by superior vena cava distention, 859 produced by venous drainage, 860 in supine position, 895

I-18

Index

Medullary cavity femoral, 507, 529 humeral, 371 metacarpal, 464 phalangeal, 6S-189 of second rib, 805 Medullary sponge kidney, 1033 Megacolon, 979 Megaesophagus, 946 Melanoma, 969 Membranous bone fissures caused by, 37 fracture simulated by, 41 parietal fissures and matrix of, 33 Mendosal suture fracture simulation by, 1S–19 occipital bone and, 1S–16 occipital and parietal fissures and, 37 persistent, 42, 43 synchondrosis and, 37 Meningioma of the anterior fossa, 28 changes of, 59 of the planum sphenoidale, 59 presphenoid bone and, 60 sphenoid wing, 1S–35 Meniscus discoid lateral, 546 medial, 7S–209, 551 Mental foramen, 81 Mesenteric fat, 938, 976 Metacarpal sign, 463 Metacarpals, 454–466, 6S–186–6S–187 attempted formation of accessory, 436 bases of bulges in cortices at, 457 clefts at, 456 dislocation simulation in, 455 ossicles between, 6S–186 shadows at, 457, 458 epiphyseal spur on, 459 fifth base of clefts at, 433, 455 fossa at, 457 knoblike protuberance at, 456 bilateral short, 463 end-on view of, 6S–181 head of palmar-directed position of, 465 pitlike depression in, 461 proximal phalanx and, 464 first accessory ossification centers for, 6S–184, 455, 458, 459 anomalous development of, 479 knoblike variation in head of, 465 trapezium and, 462 fourth sesamoid at head of, 468 short, with positive metacarpal sign, 463 great knob of Keats and, 6S–187 heads of knoblike variation in, 466 ring lesions in, 6S–186, 460 sesamoids at, 468, 469 osseous flanges on, 464 ossification centers for accessory attempted formation of, 473 at bases of, 454, 455 of first, 458, 459 remnants of closed secondary, 455 spurring of margins of, 459

Metacarpals (Continued) second duplication anomaly of, 6S–186 lucency in base of, 458 sesamoids at heads of, 6S–187 spicules in metaphyses of, 6S–186 spurlike protuberances in, 460, 461 stenosis of medullary cavities of, 464 third metacarpal sign and, 463 osseous excrescence at base of, 461 Metaphyseal fractures, 397 Metastatic deposit costal cartilage calcification simulating, 5S–164 lateral elements of T1 simulating, 3S–99 radiolucency simulating, 16, 554 Metatarsals, 709–739, 7S–243–7S–249. See also specific bone. articulation of between first and second, 723 between third and fourth, 729 aseptic necrosis and, 733 bases of apophysis of tuberosity of, 714 clefts at, 722 irregularities of, 7S–243, 725 Lisfranc dislocations simulated at, 702 ossification centers at, 713, 714 benign cortical deficit of, 739 closing apophyses of, 7S–245 cortical thickenings of, 727 epiphyseal spur on, 711, 712 fifth additional phalanx and, 735 apophysis of bilateral transverse, 719 closing of, 7S–244, 716, 718 failure of union of, 717 and fracture of, 717 fusing of, 716 large, 7S–244 lateral position of, 715 mineralization of, 716 nonunion of, 721 position of, 7S–245 at tip of base of, 719 transverse, 7S–246 of tuberosity of, 714 unfused, 7S–247 base of fusion of to os vesalianum, 651, 721 notches in, 7S–246 spur at, 721 curvature exaggeration on, 735 duplication anomaly of, 721 epiphysis appearance delayed in, 737 head of bipartite sesamoid at, 744 deep cleft in, 734 isolated sesamoids at, 744 “lesser knob” at, 734 lucency in, 738 unusual configuration of, 734 physes closure at, 7S–249 shafts of proximal phalanx of, 738 short, 736, 737, 738 trabeculations on, 718 tuberosity of, 715 first base of articulation between second and, 723 epiphyseal line at, 724 ossification center duplication at, 713

Metatarsals (Continued) distal end of accessory ossification center at, 710, 711, 712 developmental notch in, 710 epiphyseal line in, 7S–241, 7S–242 fissures in metaphysis of, 7S–243 “great knob of Keats” in, 734 head of dorsofibular process of, 712 extension of into phalangeal fossa, 750 fossa in, 712 pseudoepiphysis at, 712 sesamoid at, 745 knoblike expansions of, 709, 710 medial sesamoid at, 7S–249 os intermetatarseum and, 7S–249 shadows confusing appearance of, 7S–241, 7S–242 short, and second, 726 fourth base of cleft at, 7S–248, 728 fossae at, 725 closure of physes of, 7S–249 cuboid and, 7S–247 duplication of, 738 joint between third cuneiform and, 7S–242 short, 738 fracture simulation in, 720 fusion of between fourth and fifth and os intermetatarseum, 731 between lateral cuneiform and, 650, 701 joint space in and aseptic necrosis, 733 nutrient channels for, 728 os intermetatarseum arising from, 7S–248 ossification centers for tuberosity of, 715 second flat configuration of head of, 733 os intermetatarseum in, 729, 730 size and cortical thickness of, 726 tuberosity at base of, 726 supernumerary between fourth and fifth, 739 third base of accessory ossicle at, 7S–247 spur at, 726 head of fossa in, 752 sesamoid at, 744 Metatarsus adductus, 722 Metopic suture fracture simulation by, 1S–8, 1S–20 serrations of, 26 Midesophagus, 870 Midline frontal accessory bone, 27 Midodontoid process, 3S–73 Morgagni’s foramen, 907 Mouth, 764 Mucosal diaphragm, 961 Mucosal fold duodenal, 971 postcricoid impression and, 944 in small bowel, 978 of stomach, 959 with urethra, 1053 Muscle. See also specific muscle. spasm of, 146 splinting of, 925 Myeloma, 371 Myocardial aneurysm, 878 Myoma, 1056 Myometrial folds, 1056

N “Napoleon’s hat sign,” 238 Nare, 73 Nasal bone coronal suture shadow on, 2S–60 extra, 82 hypoplasia of, 82 normal, 82 pneumatized middle turbinates of, 83 turbinate air stripes in, 83 Nasal bridge, 82 Nasal passage, 2S–61, 764 Nasociliary nerve grooves, 82 Nasofrontal suture, 2S–51, 28 Nasolacrimal canal, 63 Nasomaxillary suture, 82 Nasopharyngeal air shadow adenoidal lucency and, 766 soft tissue masses in, 1S–38 uvula in, 63 Nasopharynx shadow of ear lobe on, 768 shadow of epiglottis on, 62 Navicular, 437–446, 6S–182–6S–184 in hand accessory ossification centers for, 6S–184, 419, 438 bipartite, 6S–182, 439 bone island in, 6S–179, 6S–183 cleft of facture simulation by, 6S–182 incomplete, 439 radial border of, 441 configuration of, 6S–183 lunate and, 444, 445 Mach effect and, 6S–182 subluxation of, 443, 444 trabecular pattern on, 440, 441, 442 trapezium and, 438 with ulnar deviation, 443 underdevelopment of, 445 undulations on radial border of, 442 unilateral development of, 437 notch on, 6S–183 os supranaviculare and, 645 ossicle near, 647, 648 rotary subluxation of, 6S–183 talus and, 7S–232 tarsal accessory, 646 bipartite abortive, 7S–237, 687 bilateral, 686 navicular, 7S–238, 688 coalition of with first cuneiform, 688 between talus and, 665 configuration of, 7S–237, 666, 687, 693 contour alteration of, 7S–240 cyst simulation in, 7S–236 duplicate ossification centers for of different sizes, 684 incomplete fusion of, 686 normal ossification from, 683, 684 joint margins of, 693 medial aspect of, 685 os tibiale externum and fusion to, 7S–238, 647, 690 incorporation of, 691 ossification of irregular, 684, 685 normal, 7S–236, 683 spur at posterior of, 7S–240, 692 trabecular pattern on, 6S–182

Index Navicular-lunate interval, 444, 445 Neck airway buckling in, 828 calcification in, 784 in flexion, 145 hair braid shadow on, 791, 792 interstitial air in, 788 soft tissues of, 763–791 tissue redundancy in, 765 tracheal indentation and, 829 Neonate anterior arch of C1 of, 87 bladder herniation in, 1048 bone dysplasia and, 667 “bone in bone” appearance in of lumbar spine, 204 of thoracic vertebrae, 189 C3 appearance in, 3S–75 calcaneal spurs in, 670 calvaria sutures overlapping in, 3 cervical rib in, 5S–155 chest wall densities in, 793 contour of radii in, 400 coronal cleft vertebrae in, 205 diaphragmatic eventration in, 920 ductus bump in, 892 esophageal distensibility in, 946 fissures in occipital, 1S–16 parietal, 33 heart size in, 875 hepatic shadow and, 923 isolette cover radiolucencies and, 824 knees of, 537 mediastinal mass simulated in, 860 metaphyseal radiolucencies in, 522 occipital configuration in, 37 ossification centers for cleft calcaneal, 667 delayed appearance of manubrium, 322 duplicate pubic, 265 parenchymal opacity in, 827 periostitis of bicipital groove shadow simulating, 355 examples of, 373, 399, 507 pneumothorax simulated in, 794 “rectal ears” in, 993 retropharyngeal soft tissues of, 770, 771 sagittal suture serrations in, 5 “sandwich” appearance of, 189 scalp folds in parietal region of, 4 small bowel patterns in, 975 spinal canal enlargement in, 3S–62 stomach distended in, 949, 950 suprasternal fossa in, 788 synchondrosis and, 1S–16 thorax of size of, 875 vertebral notches in, 189 trachea in, 828, 829, 830 ureteral transverse folds in, 1039 venous grooves in, 191 wormian bones in, 12 zygomaticofrontal suture in, 12 Neoplasm of bladder, 1051 changes of, 263 chondroid matrix of, 553 metastatic radiolucency caused by, 283 simulation of by diploic venous lakes, 7 by humeral deossification, 371

Neoplasm (Continued) new bone formation of, 527 pelvic, 988 permeation of, malignant, 371 simulation of Bertin’s columns and, 1032 by colonic sphincter, 987, 988 by epipericardial fat pads, 883, 886 by ileocecal valve prolapse, 984 by liver encroaching on stomach, 934, 953 by tracheal mucus plugs, 843 Neural arch accessory bony elements between skull base and, 93 air in pinna of, 96 apparent defects in, 97 articulation with, 138 bony spur simulating, 93 cleft in, 93 foramen in irregular between, 142 of lumbar vertebrae, 224 incomplete, 111, 211 large and spinolaminar line failure, 100 lateral masses of C2 and large, 108 low position of, 101 lung nodule simulated by, 836 un-united transverse process of L1 and, 215 Neural canal, 347 Neural foramen bifid spinous process and, 162 pseudoenlargement of, 161 Neurocentral synchondrosis, 93 Nevus, 837 Nipple shadow, 807, 836 Nose, 82–83, 2S–60–2S–61 Nostril. See Nare. Notochordal remnants at C2–C6, 3S–84 of cervical spine, 3S–84, 152 of lumbar spine end-plate depressions and, 3S–105 L4 radiolucency and, 210 producing “balloon” discs, 209 S1 cleft and, 240 thoracic, 203 Nucleus pulposus calcification, 200 Nutrient artery grooves in ilium, 4S–124, 257 Nutrient channel of calcaneus, 671, 678 of clavicle, 314 of femur, 514 of fibula, 616 of metatarsals, 728 of radius, 400 of tibia, 616 Nutrient foramina of acetabulum, 276 of distal femur, 521 of femoral shaft, 515 of fibula, 7S–219 at heads of phalanges, 477 of phalanges of fingers, 474 of toes, 756 of sacral alae, 241 scapular, 5S–148 of talus, 661 Nutrient vessels in acetabulum, 276, 489 femoral foramina for, 553 in ulna, 392

I-19

I-20

Index

O Obdurator foramen, 274 Obturator ring development, 268 Obesity accelerated bone age due to, 422 epipericardial fat pads in, 884 mediastinum and, 853 paravertebral stripe and, 864 retrorectal space and, 991 Obstructive hydronephrosis, 1024 Obturator foramina asymmetry of, 283 ossification of, 1013 spurs in, 4S–133, 274 Obturator internus muscle, 1006 Occipital bone, 37–51, 1S–16–1S–27 bathrocephalic, 1S–17, 39 closure defect in, 1S–23 condyloid of canals of, 1S–25 fossae in, 1S–25 emissary channels in, 1S–21 fissures in around foramen magnum in, 1S–16 caused by strips of membranous bone, 37 membranous, 1S–16 superior median, 41 foramen and, 45 foramen magnum and irregularities of, 1S–27 metopic suture and, 1S–20 occipital emissary vein above, 1S–21 posterior margin of, 1S–25 Inca bones and, 1S–17 localized thickening of, 48 lucencies in examples of, 1S–25 mastoids and, 1S–30, 48 malalignment of with parietal bone, 1S–16 metopic suture in, 1S–20 in newborns, 37 ossicle of in condyloid canals of, 1S–25 irregular midline, 38 in lateral projection, 1S–16 paracondylar process and, 51, 92 pneumatization of, 48 protuberance in, 1S–26, 50 radiolucencies in, 1S–23, 47 suture of anomalous, 1S–19, 43 lambdoid, 1S–18, 44 mendosal, 1S–16, 1S–19, 37 occipitomastoid, 1S–20, 44 persistent mendosal, 42, 43 sagittal, 44 squamoparietal, 51 synchondrosis and, 1S–16, 1S–18 thinning of above torcular, 1S–25 above transverse sinuses, 50 asymmetric, 1S–25 below torcular, 49 developmental, 49 examples of, 1S–24, 49 symmetric areas of, 50 transverse venous sinus groove in, 47, 48 vascular channels in, 1S–21 venous lakes of, 1S–21, 1S–22, 46 venous sinuses in location of, 1S–24 occipital protuberance and, 1S–26 prominent, 1S–23 Occipital emissary vein foramina, 45

Occipital flattening, 41 Occipital molding, 40 Occipital pacchionian impression, 45 Occipital poles, 1S–25 Occipital protuberance meningioma simulation by, 1S–35 orbital factitial density and, 2S–45 projected through frontal bone, 1S–10 sinus factitial clouding and, 2S–51 Occipital shadows overlapping, 3S–73, 128 summation, 764 Occipital suture, 43, 1S–19 Occipital vertebra, 88, 89 Occipitomastoid suture asymmetric prominence of, 1S–20, 44 in skull base, 1S–36 sutural bone in, 44 Odontoid joint, 105 Odontoid process absence of, 118 anterior aspect of, 3S–72 anterior tilt of, 117 apical ligament of, 114 asymmetry of, 116, 123 base of broad, 121 clefts in, 118 developmental variations in, 122 pseudofracture of, 129 pseudofracture portion of, 117 synchondrosis of normal, 114 sclerosis of, 116 at various ages, 115 C1 and anterior arch of, 116, 127 anterior process of, 100 lateral masses of, 126 C2 lateral masses and, 3S–71 C2 lateral masses of and, 108 clefts in, 3S–71, 127 configuration of, 123 discontinuity of, 120 double, 3S–70 fracture of, os odontoideum and old, 3S–70 hypoplasia of, 3S–71, 120, 121 lateral masses and, 112, 125 lucency in, 126 Mach effect and, 3S–73, 3S–78, 128 mastoid overlapping, 113 maxillary incisor lucency and, 126 midline cleft in, 114 open-mouth view of, 127 os odontoideum and, 119 ossicles around tip of, 124, 125 ossification centers for, 112, 113 persistent infantile, 121, 122 posterior inclination of, 124 pseudofractures of produced by Mach effect, 128 produced by maxillary incisor shadows, 126 produced by vascular groove, 128 skull base overlap and, 3S–73 space between lateral mass and, 125 spina bifida occulta seen in, 112 subdental synchondrosis in, 117 synchondrosis remnant in, 132 tongue median sulcus and, 127 turbinal configuration of tip of, 123 union failure of, 3S–70, 118

Olecranon process apophyses of apical nuclei of ossification for, 390 asymmetry of development of, 389 ossification in, 389 foramina in, 374 fossae in perforated humeral, 373 variations in appearance of, 377 nuclei of ossification for, 6S–172, 390 ossification center for incomplete union of, 391 simulated loose body or fracture of, 378 Omovertebral bone, 185 Optic canal, 59, 68 Orbital fissures clinoid processes superimposed on, 2S–44 hypoplasia of maxillary antrum and, 71 superior asymmetry of, 2S–45, 57, 58, 70 edge of, 2S–45 Orbital process, 69 Orbital rim, 70 Orbits, 68–70, 2S–43–2S–45 closed eyelids, shadow on, 70 enlargement of, 2S–46 ethmoidal air cell in facial trauma and, 2S–44 in floor of, 76 eyelid shadow and, 2S–45 factitial density of, 2S–45 fissures in, 1S–34 infraorbital groove of, 70 lesser wings of sphenoid in, 68 medial walls of, 69 occipital protuberance and, 2S–45 periglobal fat simulating air in, 70 rim of and supraorbital foramina, 2S–44 sphenoidal air cell extension and, 69 supraorbital foramina and, 2S–44 venous sinus projected through, 2S–43 zygomaticofrontal suture and, 69 Oropharynx, 764 Os accessorium supracalcaneum, 654 Os acetabuli description of, 277 examples of, 4S–135, 4S–138, 278 Os acetabuli marginalis superior fracture simulation by, 278 incomplete closure of, 4S–136 persistent, 276 Os acromiale crenated appearance of, 5S–143 destructive lesion simulated by, 290 examples of, 5S–142, 291 Os carpi centrale adult, 429 bilateral presentation of, 429 capitate fossa and, 428 example of, 420 location of, 414 Os cubiti anterius, 6S–173 Os epilunatum, 417, 427 Os epipyramis, 416 Os epitriquetrum, 416 Os hamuli proprium bilateral, 435 examples of, 418, 434 location of, 414 Os intercuneiform, 638, 650, 699 Os intermetatarseum accessory ossicle at distal end of, 652 appearance of, 652 at base of first metatarsal, 7S–248, 7S–249

Os intermetatarseum (Continued) at base of second metatarsal, 729 bilateral, 730 bipartite, 732 configuration variations of, 730 fusion between metatarsals and, 731 with incomplete ring, 7S–230 location of, 638 second metatarsal fossa and, 730 unusual configuration of, 731, 733 Os odontoideum vs. dens fracture, 119 huge, 3S–71 lack of, 120 lateral masses of C1 simulating, 120 odontoid fracture and, 3S–70 odontoid process failure with separate, 3S–70 synchondrosis and, 119 with terminal segment, 120 Os paratrapezium, 420, 436 Os perna metarsalia, 759 Os peroneum bipartite, 650 cuboid/calcaneus coalition simulated by, 650 examples of, 7S–229, 648 large multicentric, 648 location of, 638 multicentric, 649 position of, 649 small, 7S–228 Os styloideum capitate simulating, 416 examples of, 416, 431 location of, 414, 415 Os subcalcis avulsion fracture simulated by, 678 example of, 643 location of, 638 Os subfibulare with deep fossa in distal fibula, 633 examples of, 7S–224, 622 fracture simulation by, 634 large, 632 in oblique projection, 633 Os subtibiale, 629, 637 Os supra petrosum of Meckel, 1S–6, 20, 57 Os supranaviculare articulations of with talus and navicular, 645 bilateral, 7S–239, 645 examples of, 643, 644 incorporation of, 7S–239, 692 location of, 638 Os supratalare examples of, 7S–227, 639, 656, 657 location of, 638 Os sustentaculum example of, 642 location of, 638 os tibiale externa confused with, 7S–231, 660 Os sustentaculum tali, 660, 743 Os talocalcanei, 638 Os talotibiale examples of, 7S–228, 635, 642 location of, 638 Os terminale, 112 Os tibiale externum appearance variations of, 646 bilateral, 691 bipartite, 7S–229 examples of, 7S–239, 699 fracture simulation by, 7S–239, 689 fusion of, 692 huge, 7S–228, 689, 690

Index Os tibiale externum (Continued) large, 745 large bilateral, 645 location of, 638 multicentric ossification of, 690 navicular and fusion of to, 7S–238, 647, 690 incorporation of with, 691 os sustentaculi confused with, 7S–231, 660 presence of, on one side only, 691 Os trapezium secundarium, 420 Os triangulare bilateral, 6S–178, 418 position of, 414 variations of size in, 417 Os trigonum articulation of, 7S–229 examples of, 641 location of, 637, 638 multicentric, 654 normal, 653 talus fracture simulated by, 7S–227, 653 variations of, 640 Os trochleare calcanei location of, 637 ossicle representing, 627 Os vesalianum examples of, 419, 709 fused to metatarsal, 651, 721 huge, 651 location of in foot, 638 in hand, 414 Osgood-Schlatter disease, 585 Osseous bridge lumbar rib simulation by, 218 between posterior portions of ribs, 342 Osseous process arising from trapezium, 436 posterior arch of C1 and, 103 Osseous shadow, 2S–49 Osseous structures anomalous in thyroid cartilage, 169 overlapping shadows of, 457 Ossicle. See also specific ossicles. accessory, 414–421, 637–652, 6S–178, 7S–227–7S–230 of acromioclavicular joint, 318 adjacent to cuboid, 7S–230 of anterior arch of atlas, 106 C1 and anterior to, 104 posterior to, 103 of clavicle, 5S–150 at distal end of talus, 665 in hand location of, 414 as persistent ossification center, 415 between lunate and triquetrum, 418 at superior end of fibula, 598 at tip of coronoid process, 396 at ulnar styloid, 410, 411 of anterior arch of C1, 106 around tip of odontoid process, 124, 125 articulating, 7S–231 C2 and, 137 between C5 and C6, 3S–94 clavicular, 5S–153 femoral, 518 fibular examples of, 622 at head of, 7S–217 on medial side, 7S–221 in foot

I-21

Ossicle (Continued) bilateral, 651 bony, resembling sesamoids, 742 in forearm, 6S–173, 392 fracture simulation by on wrist, 448 glenoid, 294 great knob of Keats and, 466 in hand at base of index finger phalanx, 469 between metacarpal bases, 6S–186 humeral, 6S–169, 386 ligamentous calcification and, 107 of lip of acetabulum, 278 malleolar, 7S–222 at margin of glenoid fossa, 294 meniscal, 7S–209, 551 metatarsal, 7S–247 near os subfibulare, 632 occipital, 1S–16, 1S–25 partitioned, at superior end of fibula, 599 in patellar tendon, 577 in popliteus tendon groove, 548 in radioulnar joint, 6S–176 as remnant of ring apophysis, 293 representing the os trochleae calcanei, 627 of ribs, 5S–159 simulated, 105 between spinous processes of C2 and C3, 138 at sternomanubrial joint, 324 styloid, 412 of the supraoccipital bone, 38 of thyroid cartilage cornua, 781 tibial, 7S–214, 583 in toes, 7S–250 at triradiate cartilage, 4S–134 un-united ossification center for clavicle as, 313 well-corticated, 60 Osteochondritis dissecans femoral condyle and grooves of simulating, 547 irregularities of simulating, 7S–206, 7S–207, 541, 542 ossification of simulating, 543, 544 femoral head irregularities simulating, 486 fovea capitis simulating, 7S–192, 489 patella and cortical lucencies of simulating, 573 irregularities of simulating, 559 phalangeal epiphysis simulating, 750 tarsal navicular simulating, 7S–236 triangular radiolucency simulating, 553 Osteochondroma epiphyseal, 544 femoral “tug” lesion simulating, 519 fibular “tug” lesion simulating, 602 metacarpal head variation simulating, 465, 466 osseous articulation and, 154 Osteochondrosis, 267 Osteogenesis imperfecta, 12 Osteoma mandibular coronoid process and, 81 osteoid, 515 Osteomyelitis, 2S–51 Osteopenia, 511 Osteophyte intraarticular, 7S–208 mediastinal mass simulation by, 196 Osteoporosis calvarial thinning in, 32 cortical thinning of phalanges in, 478 in femur endocortical scalloping in, 514 metaphyses of

I-22

Index

Osteoporosis (Continued) lucency in, 511 radiolucencies in, 520 in necks of, 497, 504 trabeculation and, 510 in hand, 6S–189 “Herringbone” pattern and, 371, 372 major trabeculae reinforcement in, 503 parietal thinning in postmenopausal, 36 permeative bone destruction simulated by, 637 postmenopausal, 36 pseudocyst in toes in, 758 spurred vertebra in, 228 Osteoporosis circumscripta, 14 Osteosclerosis of middle phalanx of fifth finger, 477 of newborn, 522 of premature infants, 507 sacral density and, 241 Ovarian malignancy, 1010 P Pacchionian depression, 1S–3, 8, 9 Pacchionian granulation, 1S–3, 8 Pacchionian impression, 45 Paget’s disease changes in pelvic brim simulating, 262 occipital radiolucency and, 14 trabeculation and, 498 Palate hard, 766 soft, 766, 769 Pancreas calcification of, 940 enlargement of, 964 impression of on stomach, 956 Pancreatic duct, 1004 Pancreatic rest, 967 Paracondylar process arising from the occipital bone, 92 epitransverse process and, 92 example of, 51 unilateral, 88 Paraglenoidal sulcus, 4S–124, 4S–125, 258 Paramediastinal stripe, 861 Paranasal sinus, 71–77, 2S–46–2S–54. See specific type. Paraspinous fat, 864, 865 Paraspinous mass paravertebral stripe simulating, 862 pleural reflection simulating, 822 spinal facet joints simulating, 3S–102, 201 Parasternal stripe, 850 Paratracheal reflection, 815 Paratracheal soft tissue, 832 Paratrochlear bone, 386 Paravertebral soft tissue bulge, 866, 867 Paravertebral stripe examples of, 861, 862 fat displacing, 864 in narrow chest, 863 Parenchyma abnormalities of azygos lobe simulating, 844 costal cartilage calcification simulating, 797, 826 costoclavicular fascia calcification simulating, 797 hypertrophic spur simulating, 833 pulmonary opacities simulating, 838 scapular soft tissue simulating, 804 various shadows simulating, 793

Parenchyma (Continued) density in, 839 nodules of, 837 opacity of, 827 thinning of, 1024 Parietal bone, 33–37, 1S–13–1S–15 external table of, 1S–15 fissures in, 1S–13, 33, 37 foramina in, 1S–13, 1S–14 hyperostosis corticalis generalisata in, 1S–15 hyperostosis parietalis in, 1S–15 localized thickening of, 1S–4 lucencies in, 34 malalignment of, 1S–16 striations over, 1S–2 sutures in, 33, 34 vascular markings in, 1S–13, 1S–28, 36 Parietal foramina 3-dimensional CT of, 36 examples of, 35 normal, 34 paired, 35 without a central dividing strip, 35 Parietal thinning, 36, 37 Parieto-occipital hyperostosis, 1S–4 Parotid stone, 768 Parous women, 4S–124, 258 Parson’s knob, 581, 582 Patella, 556–579, 7S–211–7S–214. See also Knee. accessory ossification centers for asymmetric development of, 561 closure of, 7S–211 examples of, 563 apophyses of, 562 bipartite, 567, 568, 570, 571 caudal extensions of, 7S–214 clefts in, 558, 566, 567 contour of elements of, 568 developmental variations in, 7S–211, 560 dorsal defect of, 7S–212, 7S–213, 573, 574 elongated, 7S–211 enthesopathy and, 577 fossa of in articular surface of, 578, 579 in bipartite, 570, 571 fracture in superior aspect of, 560 horizontal bifid, 572 inferior pole of accessory ossification center at, 565, 566 configurations of, 576 fragmentation of, 561 ossification patterns of, 564 irregularity of, 556, 558, 559 medial aspect of, 567 ossification of, 559, 575 ossification patterns of, 7S–211 partitioned, 572 posterior aspect of, 7S–214 sclerosis in, 573, 574 segmented, 7S–212, 569 septa definition in, 7S–212 stippling of, 557 superior pole of flangelike projection on, 575, 576 lucency of, 7S–213 ossification centers for, 559, 560, 561 “teeth” of, 572 tendon of, 577 tripartite, 570, 571 variations in, 558 Patella alta, 566 Patella cubiti, 390 Pathologic fracture, 504 Pectoral folds, 793, 806

Pectoral muscle shadows, 799, 800, 824 Pectoralis major muscle absence of, 800 humeral insertion of, 6S–170, 368 sternal insertion of, 807 Pectus excavatum, 880 Pedicle absence of at C5, 165, 166 at C7, 185 jumped facet simulated by, 157, 167 at L3, 224 at T12, 203 asymmetry of, 3S–79, 143, 195 “elephant nose,” 223 enlarged at L4, 225 erosion simulation in, 194 hypoplasia of, 212 in lumbar spine, 3S–105, 208 margins of, 161 “pig snout,” 222 sclerotic, 3S–93, 207 scoliosis and, 226 shadows of tubercle on, 203 target, of T12, 203 thinning of, 3S–100, 195 thoracic huge, 204 narrow, 194 thoracolumbar junction and, 3S–100, 195 thoracolumbar spinal canal and, 207 vertebral facet and, 3S–89 Pedicular ring shadow, 203 Pelvic digit, 4S–129, 264 Pelvic “ears” avulsive lesions and, 263 caudad extensions and, 262 examples of, 4S–128 fracture simulation by, 4S–129 Pelvic girdle, 257–284, 4S–123–4S–138 Pelvis acetabular protrusion into, 489 brim changes in, 262 Cooper’s ligaments in, 1009 density in, 1010 epiploic appendages in, 1010 evanescent shadows in, 1007 extrarenal, 1037 fat in, 988, 1050 fracture of, 263 iliac vein in, 1008 immature, 265 ischial tuberosities and, 4S–133 kidney in, 1020 levator ani muscles in, 1006, 1007 lipomatosis in, 989, 990 obturator internus muscles in, 1006 pelvic colon and, 988 phleboliths in colonic diverticula simulated by, 999 configuration of, 1008 examples of, 1014 multiple, 1013 soft tissues of, 1006–1015 renal duplication of, 1036 fat in, 1033 papilla entering, 1028 “pigtail,” 1039 ureter duplication and, 1044 vascular impressions on, 1034 sacroiliac joints and, 253 sigmoid colon and, 1008 ureter duplication and, 1044

Penile suspensory ligament, 1053 Pericardium, 880, 881 Periductal fat, 1001 Periglobal fat, 70 Perinephric fat, 937 Periosteal proliferation, 4S–131, 266 Periostitis femoral, 7S–197, 512 fibular, 604, 606 in fingers, 464, 475 in forearm, 399, 402 humeral bicipital groove shadow simulating, 355 deltoid muscle insertion simulating, 6S–170 lateral epicondyle flange simulating, 373 projection of cortex of humeral neck simulating, 361 tendinous insertions simulating, 364 in newborns, 373, 399, 507 pelvic, 262 scapular, 296 tibial, 611, 612 tibial tuberosity simulating, 595 in toes, 7S–250, 755 Perirectal fat, 989 Perirenal space, 937 Peristalsis, 1040, 1046 Peristaltic contraction, 970, 976 Peristaltic events, 961 Peristaltic wave, 947, 960, 1046 Perisutural sclerosis, 13 Peritoneal cavity, air in, 936 Peritoneal fold, 970 Periureteral fat, 1010, 1041 Perivesical fat, 1047, 1048 Peroneus brevis tendon, 709 Peroneus longus tendon, 652, 707, 708 Perpendicular spiculation, 525 Perthes disease, 486 Petroalar bar, 1S–37 Petroclinoid ligament calcification dense nodular form of, 1S–32 heavy, 19, 66 os supra petrosum of Meckel and, 20 physiologic, 22 unusual pattern of, 1S–5 Petrous bone, 20 Petrous pyramid, 56–57, 1S–31–1S–33 cochlear densities in, 1S–32 foramina in, 1S–33 internal auditory meatus of, 1S–34 petroclinoid ligament calcification and, 1S–32 ridges of asymmetry of, 1S–31, 1S–32, 56 developmental variations in, 1S–33 rounded bony knob on, 1S–33 tips of, 1S–31, 56 Phalanges. See Finger; Thumb; Toe. Pharyngeal tonsils, 1S–38, 767 Pharynx air shadow of, 2S–56, 79 overlapping shadows of, 129 pseudomass of, 765, 943 Phlebolith colonic diverticula simulated by, 999 configuration of, 1008 in corpora cavernosa, 1055 examples of, 1014 multiple, 1013 “Pig snout” pedicle, 222 Pineal gland calcification habenular commissure and, 19 tentorium cerebelli and, 23

Index Pinna, 96 Piriform muscle, 1012 Pisiform, 449–454, 6S–185 accessory, 421 bipartite, 451, 452 calcification of, 414 exostosis of, 453 exostosis-like process on, 453 fusion of triquetrum and, 6S–185, 454 irregularity of, 449, 450, 451 large, 451 low position of, 452 multicentric, 450, 452 pseudarthrosis between hamate and, 454 Pituitary stone, 24, 25 Plantar fascia calcification, 682 Plantar ligament, 682 Plantar soft tissue, 682 Planum sphenoidale normal, 61 pneumatization of, 66 simulation of meningioma of, 59 unfused, 61 Pleura, 810–823 azygos elements in, 815, 816, 817, 818 calcification of, 813 costophrenic angles in, 811 density in, 839 effusion of, 811, 920 esophageal reflection of, 869 esophageal stripe of, 822 extrapleural line and, 852 fissure of accessory, 819, 820 interlobar, 821 lingular, 818 major, 821 minor, 819, 820 interlobar surfaces of, 820 mediastinal line of, 823 mediastinal stripe of, 823 paramediastinal stripe and, 861 pneumothorax simulated in, 810, 813 reflection of left paratracheal, 815 of mediastinal, 814 over inferior vena cava, 813, 822 scapular spine superimposed on, 820 subpulmonic effusion in, 812 thickening of fat simulating, 801, 802 subcostal muscle simulating, 798, 810 vertical fissure line of, 821, 822 Pleural line, 815, 816, 820 Pleuritis, 811 Plicae colliculi, 1052 Pneumobilia, 1001 Pneumocyst of left ilium, 258 Pneumoencephalogram, occipital thinning simulating, 50 Pneumomediastinum lucent lung simulating, 868, 869 Mach effect and, 869 sternal retraction simulating, 852 thymus simulating, 901 Pneumonia, 824, 908 Pneumonitis, 827, 839, 907 Pneumopericardium isolette cover radiolucencies simulating, 824 pleural fissure simulating, 821 shadows simulating, 877 subepicardial fat simulating, 880

I-23

Pneumoperitoneum abdominal fat simulating, 927 abdominal lucency simulating, 927 air beneath breasts simulating, 929 with an air–fluid level, 928 colon superimposed on stomach simulating, 928 colonic interposition simulating, 930, 931 “double wall” sign and, 938 fat around liver simulating, 929, 930 Mach effect simulating, 925 mesenteric fat simulating, 938 subdiaphragmatic fat simulating, 925, 926 Pneumothorax axillary skin fold simulating, 796, 806 breast compression simulating, 806 costochondral junction simulating, 5S–159 descending aorta simulating, 810 fifth rib simulating, 340 pectoral skin fold simulating, 806 pleural lobe fissure with, 819 poor positioning simulating, 810 ribs and confluence of simulating, 805 fusion of simulating, 342 grooves of simulating, 5S–161 medullary cavity lucency of simulating, 805 scapular spine shadow simulating, 804 simulation of with emphysema, 813 skin fold simulating in a 31⁄2-year-old, 793 in the elderly, 794 examples of, 795 in neonates, 794 with pectoral muscle shadow, 800 stomach position simulating, 811 subcostal muscle simulating, 798, 810 T2 transverse process simulating, 805 vertical pleural fissure line simulating, 821 Polycystic disease, 1033 Polyp, 966, 998 Polypoid lesion, 958, 993 Polypoid mass, 983 Polyposis coli, 992 Ponytail shadow, 1S–2 Popliteus tendon, 547, 548, 549 Postcricoid impression, 944 Postmenopausal osteoporosis, 36 Postobstructive atrophy, 1024 Preauricular sulcus, 4S–124, 258 Pregnancy and cardiac changes, 881 Presbyesophagus, 946 Presphenoid bone, 60 Prevertebral fat stripe, 774 Properitoneal fat line, 937 Protrusio acetabuli, 4S–134, 275 Provisional calcification, 522 Psammomatous calcification, 1010 Pseudo “fat C2 sign,” 139 Pseudocalculus sign, 1003, 1004 Psoas muscle absence of, 1016 asymmetry of, 1016 bladder configuration and, 1050 fat between bundles of, 924 lucency of, 923, 924 lucent stripes in shadow of, 924 origin of, 865, 866 shadow of, 214 visualization of, 924 Pterion, 59

I-24

Index

Pterygoid bones, 62 Pterygoid plate pneumatization of, 77 superimposition of, 2S–57 Pterygospinous bar, 1S–38 Pubic bones, 272 Pubic ligament, 1013 Pubic rami contour of upper aspects of, 4S–131, 266 nondevelopment of, 4S–131 periosteal proliferation of, 4S–131, 266 Pubis, 265–275, 4S–131–4S–133. See also Symphysis pubis. fossae in inferior rami of, 273 ischial radiolucency and, 274 obturator foramen, spurs in, 4S–133, 274 obturator ring, development in, 268 ossification centers for duplicate, 265 un-united, 4S–132 spurs on, 4S–132, 273 thin bone below superior ramus of, 272 Pulmonary artery, 839, 882, 893 Pulmonary consolidation, 825 Pulmonary disease, 824 Pulmonary infiltrate, 809 Pulmonary ligament, 814 Pulmonary nodule aortic arch branches simulating, 838 density in, 841 hypertrophic facets producing, 835 hypertrophic spurs simulating, 834 neural arches simulating, 836 rib ends simulating, 351 scapular angle simulating, 848 transverse process simulating, 351, 835 Pulmonary pseudolesion, 197 Pulmonary vein configuration of, 840 confluence of, 841, 842 esophageal indentation and, 945 prominence of, 839 shadow of, 877 “snowman heart” and, 906 “Pyloric star,” 965 Pylorus antrum and, 935 biliary calculus simulated by, 1001 lucent folds of, 935 Pyriform sinus air in, 182, 771 barium in, 943 deep, 788 Q Quadriceps tendon, 554 R Radiolucency above acetabula, 283 in acetabulum, 4S–137 in aging calvaria, 14 auditory canal air as discrete, 54 bifid sternum and, 328, 329 bilateral factitious in tibial plateaus, 587 in bladder, 1051 in buttocks, 1006 calcaneal cyst simulated by, 671 in and between cuneiforms, 704 of dorsum sellae, 1S–40 external occipital protuberance and, 50

Radiolucency (Continued) femoral cystic lesion simulated by, 553 epiphyseal in medial aspect of distal, 540 normal anterior segment of, 552 in head of, 7S–192 of medial condyle, 7S–207, 143 metaphyseal in medial aspect of, 523 osteosclerosis of newborns and, 522 triangular in, 520 in necks of asymmetric, 7S–195 examples of, 497, 499, 504 with sclerotic borders, 7S–196 of notch, 554 os acetabuli marginalis superior and, 4S–136 osteochondritis dissecans simulated by, 553 residual posterior defects and, 7S–203 fibular, 7S–219 in forearm clefts in radial metaphyses of, 397 radial tuberosity of, 398 beneath heart shadow, 809 of hemithorax, 800 in hip, 491 humeral caused by fossae above capitellum, 388 caused by pectoralis major muscle insertion, 368 epicondyle ossification center fracture simulated by, 383 of trochlea growth plate, 383 ilial, 4S–126 of inferior vena cava, 900 in infundibula, 1033 in ischia, 274 from isolette covers, 824 at L4, 210 around liver, 929, 930 lumbar spinous process degeneration and, 230 in medial malleolus, 628 mediastinal, 851 in mediastinum, 870 metastatic deposit simulation by, 16 in metatarsal, 7S–247 occipital, 1S–23, 47 pneumomediastinum as, 868 produced by tibial tubercle, 594 pterygoid bone pneumatization producing, 62 ringlike in carpal tunnel projection, 6S–181 in femoral neck, 500 of scapula wing, 296 of suprasternal fossa, 789 thymic, 904, 907 tibial, 596, 597 upper humeral notch as, 360 Radioulnar joint dislocation simulation of, 6S–175, 403 ossicle of, 6S–176 Radius bone flanges of, 402 bowing of, 401 contour undulations in, 400 epiphyses of cleft, 409 epiphyseal plate superimposition and, 408 line of, 6S–176 spurs on, 404

Radius (Continued) heads of epiphysis of cleft, 394 sclerotic appearance of, 393 spur arising from, 395 interosseous ridges of, 399 metaphyses of clefts in, 6S–172, 395, 397 notches on, 394, 395 spurs on, 401, 402 nutrient channel in, 400 physeal closure in, 407 separation of, 403 short, 6S–174 spicules in epiphyseal cartilage of, 406 styloid process of long distal extension of, 6S–177 Mach effect of, 6S–182 ossification centers for, 409 triangulation of corpus and, 423 tuberosity of, 398 Ramus, mandibular, 2S–58, 80 “Rectal ears,” 993 Rectum fat and, 989 gas in, 1051 “kissing” artifacts in, 996, 997 levator ani muscles and, 996 obesity and, 991 rupture of, 998 walls of, 999 Rectus capitis muscles, 1S–38 Rectus femoris, 4S–135, 263 Renal artery, 1034 Renal disease, 1025 Renal hilus, 1034 Renal papillae, 1024, 1027, 1028 Renal uncus, 1031 Retention cyst, 73 Retrocardiac space, 840 Retroesophageal course, 894 Retroiliac artery, 1041 Retroperitoneal fat, 1022 Retroperitoneal fibrosis, 1042 Retropharyngeal abscess, 770, 772 Retropharyngeal soft tissue displacement, 106 Retrorectal space, 991 Retrosomal cleft, 206 Retrospondylolisthesis of L5, 233 Retrosternal line, 848, 849, 850 Rhomboid fossa bilateral, 5S–151 in clavicle examples of, 313, 315 overlapping shadows of, 5S–150 symmetry of, 5S–151 clavicular exostosis-like extension at site of, 5S–151 Rhomboid ligament, 315 Rib, 335–353, 5S–155–5S–165 accessory elements of, 336 anterior ends of extrapleural masses simulated by, 335 fossae in, 340 fusion between, 340 lucency in, 339 lung nodular lesions simulated by, 351 simulated cupping of, 335 articulations of costovertebral, 5S–162 in first, 5S–156, 337, 338 between first and cervical, 5S–155, 188, 336

Rib (Continued) between first and clavicle, 5S–152 between first and second, 5S–157, 5S–159 pseudo, of posterior, 338 between scapula and, 310 between third and fourth, 5S–160 between transverse process and, 3S–104 between two, 5S–162, 5S–163 bilateral, 215 bone loss in, 346 cervical in a 2-week-old, 5S–155 anterior end of, 5S–155 articulation of at distal end of, 335 with first, 336 between first rib and, 5S–155 bilateral, 5S–155 clavicle and, 5S–150 companion shadows of, 799 confluence of first and second, 805 costal cartilage of calcification of, 5S–164, 343, 352 circular, 352 developmental variations in, 5S–158 hypertrophied, 343, 344 intrathoracic extension of, 343, 344 linear, 353 overgrowth of, 339 ring-shaped, 352 vascular calcification simulated by, 353 costochondral articulation and, 347 costochondral junction of, 5S–159 costoclavicular joint and, 317, 344 costovertebral junctions of, 344 destruction of, 346 destructive lesions of, 202 duplication of left eleventh, 350 epiphyseal line in, 5S–150 erosion simulated in, 346 fifth anomalous development of, 340, 345 fusion of fourth and, 5S–157 first absence of, 338 anomalous articulations in, 5S–156 arrangement of with second, 336 articulation of between cervical rib and, 5S–155 between clavicle and, 5S–152, 336 between second rib and, 5S–157, 5S–159 with bifurcated anterior end, 5S–158 clavicle and, 5S–160 costal cartilage calcification at, 5S–158, 797, 826 density of, 5S–156 extrapleural line and, 852 fusion of, 5S–157 jointed ligamentous calcifications and, 336 shadow of, 798 spurlike process arising from, 340 T1 and, 336 underdevelopment of, 798 un-united apophysis of, 5S–156 un-united cartilage of, 5S–156, 5S–157, 338 fourth anomalous development of, 5S–160 with articulation, 345 articulation between third rib and, 5S–160 bifid anterior end of, 345 fusion of fifth and, 5S–157 fusion of third and, 345 fracture healing simulated in, 323 fusiform appearance of, 5S–161

Index Rib (Continued) fusion of posterior portions of, 5S–157, 341, 342 grooves in, 5S–161 hypoplasia of, 335 iliac, 264 infrascapular bone and, 5S–146 intra-abdominal, 350 intrathoracic, 349 L1 and, 215 L5 and, 235 ligamentous calcifications and T1 and, 336 lumbar, 217, 218 neck curve of, 348 ninth, bulging of, 5S–163 notching simulated in, 348 osseous bridge between posterior portions of, 342 ossicles of ends of, 5S–159 proximal ends of lucencies in tubercles of, 346 simulated cysts of, 346 retrosternal line and, 850 sacral, 245, 246, 247 sclerotic lesion simulation of, 5S–163 second arrangement of with first, 336 articulation of between first rib and, 5S–157, 5S–159 bridging between third and, 341 fusion of, 5S–157 jointed, 338 lesion simulated on, 5S–160 lucency of medullary cavity of, 805 protuberance on, 5S–162 un-united cartilage of, 5S–157 shadow of, 847 short, 348 soft tissue companion shadows of, 5S–163 superimposed on diaphragm, 925 T1 and ligamentous calcifications and, 336 thin bony flanges in, 348 third articulation between fourth rib and, 5S–160 bridging between second and, 341 fusion of fourth and, 345 protuberance on, 5S–162 thymic “wave” sign caused by, 902 transverse process of cavitary lung lesion simulated by, 5S–164 elongated, 188, 350 tucklike configuration of, 348 twelfth, 5S–165, 350 unfused apophysis of, 193 well-developed cervical, 335 Rider’s bone ossification, 275 Riedel’s lobe, 937, 1000, 1001 Ring apophysis of scapula glenoid, 293 Ring lesion in femoral neck, 4S–127 in metacarpal heads, 6S–186, 460 in triquetrum, 448 Rotary subluxation of navicular, 443, 444 Rotator cuff, 6S–167

S S1 vertebra destructive lesion simulated in, 3S–120 lucencies in, 3S–118 lumbarized, 3S–117 midline cleft of, 240 ossification centers for, 3S–116, 238 S2 and, 3S–117 spina bifida occulta of, 3S–116, 248

I-25

S2 vertebra, 3S–117 Sacral canal, 249 Sacral ligament calcification, 1011 Sacral segments fusion lines of, 249 junction of coccyx with last, 251 Sacroiliac joints, 253–256, 3S–121–3S–122 absence of, 254 accessory, 240 ankylosing spondylitis and, 253, 254 appearance of, 253 appendix and, 942 bilateral accessory, 255 developmental variations in, 256 ilial spur at, 245 irregularity of, 253 obliteration of, 3S–122, 253, 254 sclerosis of, 253 secondary, 3S–122, 255 spurs on, 4S–126 unilateral accessory, 255 “vacuum” phenomena in, 255 Sacroiliac ligament, bone resorption and, 4S–124, 258 Sacroiliitis, 253 Sacrospinous ligament calcification, 249, 1010 Sacrotuberous ligament calcification, 1011, 1012 Sacrum, 238–249, 3S–116–3S–120. See also specific vertebrae. alae of absence of, 240 accessory ossification centers for, 239 defects in, 247 nutrient foramina of, 241 synchondrosis and, 239 “angel-wing,” 239 articulations with L5 and, 3S–115, 236, 237 coccyx and, 251, 252 curve of, 245 foramina in projecting through colon, 998 shadows of, 247 fossae cribrosa and, 243, 244 fracture simulated in, 241, 242, 244 iliosacral ligament calcification in, 3S–117, 239 lateral elements of, 240 lucency in, 3S–118 lumbar lordosis in, 238 nerve roots in, 3S–116 posterior arch of, 250 posterior elements and, 3S–119 ribs in, 245, 246, 247 S1–S2 of interspace of, 242 posterior widening in, 3S–117 scoliosis of, 3S–120 secondary ossification centers for, 3S–121, 3S–122 segments of, 3S–120 synchondrosis and, 239 variations in, 241, 249 wings of foramina in, 247 fossae in, 248 Saddle reflux, 1038 Sagittal intrasutural bone, 34 Sagittal suture at base of skull, 60 groove for, 1S–8 seen through occipital bone, 44 serrations of, 5 Salter type I fracture, 407 Salter-Harris type I fracture, 587, 620

I-26

Index

Sartorius muscle, 4S–126, 260 Scalp fold, 4 Scaphoid, 438, 446 Scapholunate space, 431 Scapula, 285–312, 5S–139–5S–149 acromial pseudospur in, 291 acromion processes of apophyses of, 5S–141, 5S–142 crenated appearance of, 5S–143 development of, 286 fossae in, 5S–143 irregularity of, 289 long, 5S–141 malalignment of, 297 ossification centers for premature appearance of, 285 secondary, development of, 286 secondary, os acromiale and, 290 secondary, remnant of closure line of, 289 secondary, for tip of, 297 un-united accessory, 289 stout, 5S–141 angle of, 848 apophysis of closure of acromial, 288 development failure in, 300 glenoid fossae in, 5S–144 fusion failure of, 5S–144 persistent, 5S–144, 294 ring, 292 un-united portion of, 294 articulations between ribs and, 310 clasplike cranial margin of, 302 coracoid processes of apophysis of primary, 5S–140 secondary, 287, 291 lucencies caused by, 295 ossification centers for, 285 accessory at synchondrosis of, 288 distal, 287 normal, 5S–139 premature appearance of, 285 secondary, 286 projection of, over glenoid, 295 synchondrosis of, 5S–140 curvature of distal end of, 308 defects of developmental, 307 foramina-like, 304 notchlike, 300 dysplastic, 312 foramen in, 5S–148 fossae in margin of, 5S–147 in neck of, 307 ring apophysis of glenoid, 5S–143 sclerotic margins of, 304, 305 fracture simulated in, 302, 308, 309 glenoid of cancellous bone of, 305 coracoid process projected over, 295 defects in, 295 irregularity of, 292 ossicle in, 293, 294 secondary ossification centers for, 5S–144, 293 superimposition of on thoracic pine, 200 during growth, 286 hooklike configuration of, 5S–146 infrascapular bone of, 5S–146 lateral margin density in, 311

Scapula (Continued) lucent mass simulated by, 846 malalignment in, 297 neck of excrescences on, 5S–145, 296 lucencies in, 295, 305, 306 vascular groove in, 5S–149 notch on, 301, 303 nutrient foramina of, 5S–148 os acromiale of crenated appearance of, 5S–143 description of, 290 examples of, 5S–142, 291 overlapping shadows on, 5S–148, 6S–167 radiolucency of, 296 secondary ossification centers for, 299 shadows of clavicular appearance and, 5S–152 mediastinal density simulated by, 848 pulmonary disease simulated by, 824 soft tissues over, 804 spine of cavitary lesion simulated by, 847 double cortical lines of, 5S–147 fracture simulation by, 302 overlapping lung, 804 pulmonary disease simulated by, 824 superimposition of, 820 superimposition of, 832, 860 superior end of body of, 5S–147 trabecular pattern of fracture simulation by, 308 marked accentuation of, 5S–149, 311 transverse superior ligament of, 303 upper margins of, 5S–147, 301 Schmorl’s nodes, 3S–105, 158, 327 Sciatic foramina, 260 Scimitar vein, 842 Sclerosis. See also Osteosclerosis. of acetabulum, 4S–138, 284 femoral cortical defect and, 517 of ringlike radiolucency borders, 7S–196, 500 of fingers, 6S–190 in forearm, 393 humeral intramedullary, 372 of olecranon foramen, 374 of lumbar spinous processes, 3S–113, 230 of manubrium borders, 327 of medial ends of clavicle, 313 of odontoid synchondrosis, 116 patellar, 573, 574 of pedicle, 207 in peroneus longus tendon groove, 708 phalangeal of foot, 758 terminal, 483, 484 of sacroiliac joints, 253 of scapular fossae, 304, 305 sutural early, 1S–4 squamosal, 1S–29 temporal, 1S–29 of T1, 3S–99 of thoracic vertebral end plates, 195 unilateral spondylolysis of C1 and, 97 of vertebral bodies, 3S–93 Sclerotic band, 206 Sclerotic lesion hair braid bands simulating, 4 simulated by ilial flanges, 4S–127

Scoliosis of coccyx, 3S–120, 252 manubrium and, 852 pedicle erosion simulation by, 194 of sacrum, 3S–120 simulated destruction of L4 pedicle by, 226 Sella turcica, 64–67, 1S–39–1S–42 bridging of, 1S–39, 65 clinoid processes and, 1S–40, 65, 66 double floor of, 1S–41, 67 planum sphenoidale pneumatization and, 66 pneumatization of, 67 tuberculum, 1S–40, 64 variations in, 1S–41, 1S–42, 67 Sellar spine, 1S–39 Seminal vesicle, 1015 Septum bowed, of frontal sinus, 2S–52 patellar, 7S–212 Sequestra button, 6 with hyperostosis frontalis interna, 1S–12 Serratus anterior muscle, 802, 803, 804 Sesamoid, 467–469, 740–745, 6S–187, 7S–249. See also specific bones. of foot at base of first metatarsal, 7S–248 bipartite of equal size, 741 at head of fifth metatarsal, 744 symmetric oval, 743 of unequal size, 742 bony ossicles resembling, 742 developing, 741 at fifth metatarsophalangeal joint, 744 fissurelike lucencies in, 740 intercalary, 642 at interphalangeal joint, 741 location of, 637, 638, 740 at metatarsal heads, 742, 744, 745 multipartite, 740 multiple, 740 in tibialis posterior tendon, 743 tripartite, 743 of hand at interphalangeal thumb joint, 467, 468 location of, 414, 467 at metacarpal heads, 6S–187, 468, 469 ossicle as possible, 469 in triceps tendon, 390 of knee bipartite, 549 developmental variations in, 550 popliteus groove and, 548, 549 location of ankle, 637 in patellar tendon, 577 Shenton’s line, 491 Shoulder hair braid shadow on, 792 joint of dislocation of, 5S–149, 312 “vacuum” phenomenon in, 310 Shoulder girdle, 285–353, 5S–139–5S–165 Sigmoid sinus, 56 Sinus. See also specific type. hypoplasia in, 71 vascular channels above frontal, 29 Sinusitis compartmented antra and, 2S–47 simulation of, 74 Skin folds abdominal appearance and, 923 curvilinear densities produced by, 793 pneumothorax simulated by, 793, 794, 795 psoas muscle lucency and, 924

Skin lesions, 837 Skull, 3–67, 1S–1–1S–42. See also specific bone. asymmetric, 33 base of, 60–64, 1S–36–1S–39 accessory bony elements and, 93 articulation of, 91 basipharyngeal canal and, 1S–39 bony spur arising from, 93 C1 and, 3S–63 C1 arch articulation with, 3S–64, 91, 92 C1 incorporation into, 89, 90 C1 mass assimilation at, 3S–64 C1 unfused arch and, 63 Caldwell’s projection and, 62 clinoid process pneumatization in, 63 coronal suture in, 60 ethmoid bones in, 62 foramen ovale in, 1S–37, 1S–38 foramina in basal, 61, 62 carotid, 1S–38 infraorbital, 62 jugular, 62 foramina rotunda in, 62 fossae in, 1S–38 frontal bones in, 62 intersphenoidal synchondrosis in, 64 ligamentum nuchae at, 3S–94 nasolacrimal canals in, 63 nasopharyngeal air shadow and, 1S–38 occipital condyles and, 1S–38 occipitomastoid sutures in, 1S–36 overlapping, and odontoid process, 3S–73 petroalar bar in, 1S–37 planum sphenoidale in, 61 pterygoid bones in, 62 pterygospinous bar in, 1S–38 rectus capitis muscles and, 1S–38 separation of from cervical spine, 84 suprasellar calcification simulated in, 63 suture in sagittal, 60 sphenofrontal, 1S–37, 61 sphenotemporal, 61 squamosal, 1S–37 synchondrosis in, 60, 61 tongue seen from, 766 uvula seen from, 63, 767 Waters’ projection and, 62 fossae in, 1S–28 parietal area striations over, 1S–2 suture in coronal, 1S–28 intraparietal, 33 squamosal, 1S–28 thinning of in inner table, 1S–12 in outer table, 1S–5 vascular grooves in pseudofractures produced by, 128 at vertex of, 1S–2 in vertex of, 1S–37 wormian bones in, 1S–28 “Snowman heart,” 906 Small intestine, 973–978 Soft palate configuration, 764 Soft tissue of abdomen, 922–1005 air in, 808 of arm, 836, 891 axillary, 796, 806, 860 of back, 923 bulging of, 774 at C2, 773

Index Soft tissue (Continued) calcification of in fingers, 6S–190 mandibular, 2S–57 of chest wall, 808 injury to, 3S–92, 152 mass in in ankle, 7S–226 manubrium simulating, 809 muscle and fat simulating, 7S–199 representing pharyngeal tonsils, 1S–38 soft palate simulating, 769 vertebral facets simulating, 3S–109 of neck, 763–791 calcification of, 784 hair braid shadow on, 791, 792 interstitial air simulated in, 789 normal configuration of, 765 redundancy of, 765 paraspinous, 865 paratracheal, 832 paravertebral, 861, 866, 867 of pelvis, 1006–1015 prevertebral, 773 retropharyngeal, 770, 771, 772, 774 shadows of from pectoral muscles, 800 over scapula, 804 of shoulder, 792 spinous process and, 3S–92, 152 of thorax, 792–913 Soleal line, 604, 605 Soleus muscle example of accessory, 7S–226, 637 “tug” lesion at, 602, 604 Spermatic cord, 1014 Sphenofrontal suture, 1S–37, 61 Sphenoid bone, 57–60, 1S–34–1S–36 air cell extension of, 69 density of, 70 fossae in, 1S–36 fracture simulated in, 1S–35 lesser wings of asymmetry of, 57, 58, 68 lateral strut of, 59 spurs from, 58 occipital protuberance and, 1S–35 orbital fissures of, 1S–34 pneumatization in of clinoid process, 1S–35, 59 of sphenoid sinus, 1S–36 pterion in, 59 Sphenoid sinus, 77, 2S–53–2S–54 air cell extension of, 2S–47, 59 air–fluid level in, 2S–53 ethmoidal air cell in, 2S–52, 76 extension of, 2S–46, 2S–54, 77 pneumatization of, 1S–36 pterygoid plates in, 77 sphenoidal air cell in, 2S–54, 77 temporal vascular grooves in, 1S–28 unequal development of, 1S–41 zygomatic arch and, 2S–53 Sphenoidal air cell basal foramen simulated by, 62 extension of lateral, 59, 71 orbital appearance and, 69 into sphenoid, 2S–54, 69, 77 Sphenooccipital synchondrosis, 64 Sphenoparietal venous sinus fracture simulation by, 1S–2 groove for, 7 Sphenotemporal suture, 61

I-27

Spicule, 6S–175, 6S–186, 406 Spina bifida block vertebrae at C5 and C6 with, 177 of C7, 183, 184 fracture simulation by, 131 segmentation of C2 and C3 with, 144 of the spinous process, 166 of T11, 197 of T12, 3S–101, 197 Spina bifida occulta absence of, 165 with absence of C7 pedicle, 185 of C2 and C3, 3S–71 with double spinous processes, 195 of L1 and L2, 3S–101 of L5, 3S–115 offset of left lateral mass and, 111 open-mouth view of, 112 posterior arch of C1 and, 95 of S1, 3S–116, 248 spinolaminar line absence and, 99 of T11, 3S–102 of T12, 3S–102 in thoracic spine, 3S–101, 195 Spinal canal, 3S–62, 3S–63, 85, 86 Spinal ligament calcification, 173 Spinal stenosis, 226 Spine, 84–256, 3S–62–3S–122. See specific area. Spinolaminar line absence of, 99 backward “displacement” of, 151 failure of, 100, 179 subluxation and, 145, 146 T1 vertebra failure in, 193 Spinous process configuration of, 171 elongation of, 179 off-center, 164 spacing between, 152 spina bifida of, 166 superimposition of, 202 variations in, 171 Spleen artery of, tortuous, 940 colon and flexure of, 936 interposition of between diaphragm and, 931 pressure defect produced by, 982 fat around, 930 impression of on kidney, 1017 on stomach, 954, 955 renal tumor simulated by, 1020 shadow of, 934 stomach gas bubble and, 954 Spondylitis ankylosing, 253, 254 inflammatory sacroiliac joint obliteration and, 3S–122 vertebral segmentation failure and, 198 Spondylolisthesis apparent reverse of L5, 233 “Napoleon’s hat sign” of, 238 spondylolysis and, 3S–76, 135 Spondylolysis abortive, of C5, 163 of C2, 3S–76, 135, 136 in lumbar spine, 3S–110 of neural arch of C4, 153 retrosomal cleft in, 206 simulation of in C3, 3S–75

I-28

Index

Spondylolysis (Continued) in lumbar spine, 3S–109, 221, 222 spondylolisthesis and, 135 unilateral of C1, 97, 98 Spondylosis, 3S–93, 141 Sprengel’s deformity, 185 Spur, bony arising from base of skull, 93 at base of metatarsal, 721 with femoral cortical irregularity, 525 at first costochondral junction, 5S–159 at navicular, 692 plantar ligament attachment site simulating, 682 Squamoparietal suture, 51 Squamosal suture fracture simulation by, 1S–4 normal sutural sclerosis of, 13 posterior portion of, 13 sclerotic, 1S–29 in skull base, 1S–37 wormian bones in, 1S–28 Stenosis hypertrophic pyloric, 963 of metacarpals, 464 spinal, 135 Stenvers’ projection, 1S–29, 1S–31 “Step” defects, 192 Sternocleidomastoid muscle shadow, 798 Sternocostal joint, 343 Sternomanubrial joint dorsal spine and, 5S–154 ossicle at, 324 sternum irregularity at, 327 Sternum, 322–334, 5S–154–5S–155. See also Manubrium. congenital bifid, 328, 329 costal cartilage calcification and at end of first rib, 797 xiphoid process and, 330, 331 developmental variations in, 322, 324 diaphragm insertions on, 914 episternal processes of, 325 foramina of, 330 indentation on, 5S–154 lesions in, 852 manubrium of duplication of centers of, 322 mediastinal mass simulated by, 326, 327 ossification centers for delayed appearance of, 322 double, 323 mediastinal mass simulated by, 852 sclerotic borders of, 327 nonsegmentation of, 325 ossification centers for in body of absence of, 324 accessory, 322 duplication of, 322 fusion of, 325 superimposed on ribs, 323 variability in size of, 324 in manubrium of delayed appearance of, 322 double, 323 mediastinal mass simulated by, 852 partial bifid, 5S–154 pectoralis major muscle insertion and, 807 pectus excavatum of, 880 radiolucency in, 328 retraction of, 852

Sternum (Continued) segment development in, 328 sternomanubrial joint of, 5S–154, 327 superior margin irregularity in, 327 xiphoid process of accessory center for, 5S–155 anterior flexion of, 332 bifid, 333, 334 configuration of, 330 elongated, 334 gap between sternum and, 332 partitioned, 333 sternal mass lesion simulated by, 331 Steroid use, 853, 854 Stomach, 949–965 air bubble in air–fluid level and, 928 distance between diaphragm and, 812 polyp simulation by, 966 polypoid lesion simulated by, 958 air-filled, 927 antrum of diaphragmatic, 962 fluid-filled, 935 gallbladder impression on, 972 pancreas in, 964 prolapse of mucosa into, 966 “pyloric star” seen through, 965 spasm of, 963 superimposition of, 935 ulceration of, 960, 961 areae gastricae of, 957 cardia of, 951, 952 colon superimposed on, 928 costal margin impression on, 955, 956 distended, 949, 950 elevated, 972 esophageal mucosa and, 951, 952 esophagogastric junction in, 951 filled, 955 fundus of fat between diaphragm and, 927 fluid-filled, 932 position of, 812 splenic impression on, 954 gas bubble of distance between diaphragm and, 920, 921 liver encroaching on, 934, 953 spleen and, 954, 955 gastric diverticulum in barium drip simulating, 959 developmental, 953 location of, 952 partial, 962, 963 gastric erosions in, 958 gastric impressions in and liver, 953 gastric mucosa in, 957, 958 greater curvature of, 964 high position of, 811 impression on by colon, 964 “kissing” artifacts in, 959 liver and, 920, 953 mass encroaching on, 936 mucus in, 974 muscle band of, 961 pancreatic impression on, 956 polypoid filling defect in, 950, 951 pyloric canal in, 965 pylorus of, 1001 size of compared to abdomen, 949 splenic impression on, 954, 955 transverse mucosal folds of, 959 ulceration of antrum of, 960 Straight back syndrome, 882

Stress fracture calcaneal, 681 patellar, 575, 576 tibial, 597 Stylocarpal impaction, 413 Stylohyoid ligament calcification examples of, 775 foreign body simulation by, 777, 778 with multiple articulations, 777 with multiple segments, 776 with thyroid cartilage, 781 Styloid process bilateral of L1, 213 of L4, 214 of T9, 202 in neck, 775, 776 radial accessory ossicle at, 415 distal extension of, 6S–177 Mach effect of, 6S–182 ossification centers for, 409 ulnar configuration of, 412 rotary subluxation and, 6S–183 size of, 412, 413 styloid ossicles and, 411 ununited ossification centers for, 411 unilateral of L1, 213 of L4, 214 Subclavian artery calcification of, 890, 891 clavicles and, 5S–152 esophageal impression of, 948 large, 891 origin of, 948 pulmonary opacity produced by, 838 shadows of, 839, 890 Subclavian reflection, 815 Subcostal muscle shadow, 798, 810 Subdiaphragmatic fat, 925, 926 Subepicardial fat, 880, 881 Subhepatic cecum, 938 Subluxation in adults, 145 of cervical vertebrae, 3S–80, 3S–81, 3S–82 in flexion, 147 hangman’s fracture and, 133 posterior spinous process simulating, 155 rotary of navicular indicators of, 444 simulated, 6S–183, 443 simulation of by metacarpal/phalanx relationship, 464 by metacarpal/trapezium relationship, 462 spinolaminar line and, 145, 146, 151 voluntary bilateral painless, of naviculars, 443 Submandibular mass, 765 Submaxillary gland calculus, 782 Submucosal venous plexus, 944 Subphrenic abscess, 932 Subpulmonic effusion, 812, 920 Subsagittal suture, 34 Subtalar joint, 659 Sulcus. See specific type. Supra azygous recess, 945 Supra-acetabular notch, 282 Supraclavicular fossa effacement of, 336 floor of, 798 Supraclavicular mass, 336 Supraclavicular nerve canal, 5S–150, 314 Supracondylar process, 374, 375

Supraoccipital bone, 38 Suprapubic ligament, 273, 274 Suprarenal mass, 1019 Suprasellar calcification folded ear shadow simulating, 63 temporal sutural sclerosis simulating, 1S–29 Supraspinous ligament ossification, 230 Suprasternal fossa, 788, 789 Sustentaculi, 660 Sustentaculum tali cyst simulated by, 680 fracture simulation produced by, 679 os sustentaculum tali between talus and, 660 Sutural bones, 12, 44 Sutural sclerosis coronal, 14 nasofrontal, 2S–51 occipital, 43 squamosal, 13 Suture. See specific type. Symphysis pubis accessory ossification centers for, 272, 274 asymmetry of, 1051 cyst simulation in, 272 irregularities of, 4S–132, 4S–133, 273 malalignment of, 4S–133, 274 postpartum changes in, 4S–132, 4S–133, 273 wide, 4S–133, 274 Synchondrosis in a 2-year-old, 60 basisphenoid–basiocciput, 60, 61 of C2 ossification centers, 129 coracoid, 5S–140, 288 in hyoid bone, 778 between ilium and ischium, 4S–130, 264 intersphenoidal, 64 ischiopubic, 267, 268, 269 mendosal suture and, 37 neurocentral, 93 in occipital bone, 1S–16, 1S–18 in odontoid process at base of, 114, 115, 118 hypoplastic, 121 persistent, 3S–70 remnant of, 132 os odontoideum and, 119 between sacral body and alae, 239 sphenooccipital, 64 sternocostal joint as, 343 Syndesmotic membrane, 7S–219 Synostosis, 343 Synovial capsule ossification, 502 Synovitis, 492 Synovium, 7S–196

T T1 vertebra lateral elements of, 3S–99 omovertebral bone between C5 and, 185 spina bifida of, 196 spinolaminar line failure in, 193 spinous process of, 193 transverse processes of accessory rib elements at, 336 calcifications between rib and, 336 ossification centers for, 3S–99, 192 shadow of, 3S–100 unfused apophysis of, 192, 193 T2 vertebra, 805 T3 vertebra, 201 T4 vertebra articulation between T3 and, 201 jointlike union of, 3S–103

Index T5 vertebra articulation between T6 and, 201 jointlike union of, 3S–103 T6 vertebra articulation between T5 and, 201 butterfly vertebra at, 199 T7 vertebra, 199 T9 vertebra, 202 T10 vertebra, 197 T11 vertebra articulation between T12 and, 202 spina bifida of, 197 spina bifida occulta of, 3S–101 spinous process of, 196 T12 vertebra articulation between T11 and, 202 costovertebral articulation and, 3S–104 notch in articulating process of, 202 spina bifida of, 3S–101, 197 spina bifida occulta of, 3S–101, 3S–102 target pedicle of, 203 wedged appearance of, 227 Talar beak, 657, 658 Talocalcaneal coalition, 659 Talocalcaneal dislocation, 659 Talonavicular joint, 657 Talus, 653–666, 7S–230–7S–232 anterior processes of, 664 appearance of, 630 beak of, 7S–231, 657, 658 cyst simulated in, 656 dislocation of simulated, 659 distal end of, 665 fibular epiphysis shadow on, 7S–234 foreshortening of, 659 forme fruste of bipartite, 656 fossa of, 661, 662 navicular and, 7S–232, 665, 666 nutrient foramen of, 661 os supranaviculare and, 645 ossicle between lateral malleolus and, 627 ossification of bipartite, 694 of dome of, 655 partitioned, 7S–232, 663 posterior process of huge, 653 malleolus overlapping of, 659 os accessorium supracalcaneum and, 654 os trigonum and articulation of with, 7S–230 fracture simulated by, 7S–227, 653 saucerlike depressions on, 655 trabeculae on, 7S–231, 658 Talus accessorius examples of, 7S–231, 639 location of, 637, 638 Talus partitus, 7S–232, 663 Talus secundarius example of, 638 location of, 637 partially fused, 660 Tarsal bone, 637–708, 694, 695, 7S–227–7S–242. See also specific name. Tarsal coalition, 664 Tarsal navicular, 683–693, 7S–236–7S–240. See Navicular, tarsal. Teeth, shadows of and C2, 3S–73 Temporal artery grooves, 52 Temporal bone, 52–53, 1S–28–1S–29 convolutional impressions in, 1S–28 hyperostosis interna of, 53 lucency of, 53 os supra petrosum of Meckel in, 57

I-29

Temporal bone (Continued) sclerosis in, 1S–29 temporal artery grooves in, 52 thinning of, 1S–29 vascular grooves in, 1S–28, 52 zygomatic arch and, 2S–55, 78 Temporomandibular ligament, 2S–56 Tendon interdigitation spurs, 572 Tendon sheath attachment, 475 Tentorium cerebelli calcification, 22 Thigh, 486–556, 7S–192–7S–210. See Femur. Thoracic cage, 285–353, 5S–139–5S–165 Thoracic inlet esophageal shift and, 944 tracheal indentation and, 829, 831 Thoracic lordosis, 3S–101 Thoracic spine, 189–204, 3S–98–3S–104. See also specific vertebrae. annuli simulated in, 3S–102, 201 “bone in bone” appearance of, 189 bumpy, 3S–103 butterfly vertebra in, 198, 199, 200 costovertebral articulation and degeneration in, 197 hypertrophy in, 3S–103 end plates of, 190 intervertebral disc development in, 198 kyphosis and, 3S–100 mediastinal mass in, 196 neural arch closure at, 211 normal, 190 notches on in anterior corners of, 190 central, 189 posterior vascular, 3S–99 notochordal remnants of, 203 nucleus pulposus calcification in, 200 paramediastinal stripe and, 861 paraspinous mass simulation in, 3S–102, 201 pedicles of asymmetry of, 195 erosion simulation in, 194 size of, 194, 204 pseudofractures of, 200 rib and, 202 ringlike shadow on, 3S–100 “sandwich” appearance of, 189 sclerotic vertebral end plates in, 195 scoliosis and pedicular erosion in, 194 segmentation of, 3S–101, 198 spina bifida occulta of with double spinous processes, 195 with segmentation anomalies, 3S–101 spinous processes of, 3S–103 “step” defects in, 192 thoracolumbar junction of interpedicular distance at, 193 pedicle thinning at, 3S–100, 195 transverse process of articulation between rib and, 3S–104 ossification centers in, 192 venous grooves in, 191 venous sinus grooves in, 3S–98 venous sinus “holes” in, 190 Thoracolumbar junction interpedicular distance at, 193 pedicle thinning at, 3S–100, 195 Thoracolumbar kyphosis, 193 Thoracolumbar spinal canal, 207 Thorax comparative size of, 875 curvilinear densities in lower, 793 migration of colon into, 919 migration of kidney into, 918, 919 soft tissues of, 792–913

I-30

Index

Thumb abduction of, 462 adduction of, 462 bifid terminal digit of, 482 epiphysis of, 479, 480 extensor pollicis brevis tendon insertion into, 474 navicular subluxation and, 444 phalanges of accessory ossification center formation in, 473 cleft epiphysis of, 470 distal fissure adjacent to, 481 fossa in, 482 middle and, 479 middle and distal, 479 proximal cleft epiphysis of, 470 notch in base of, 471 spurlike excrescence in, 474 terminal, 483 sesamoid at interphalangeal joint of, 467, 468 triphalangeal, 6S–189, 476 Thymus, 901–913 atelectasis simulated by, 907 atrial appendage enlargement and, 905 cardiomegaly simulated by, 877, 903, 904 configuration variations in, 901, 906 dextrocardia simulated by, 903, 908 extension of, 905 huge, 903, 904 mediastinal fat simulating, 853 mediastinal radiolucencies and, 851 pneumonia simulated by, 908 pneumonitis simulated by, 907 posterior mediastinal, 908 presentation of, 902, 903, 907 radiolucency in, 907 residual, 909, 910, 911, 912, 913 “sail” configuration of, 905 shadow of, 906 “snowman heart” and, 906 “wave” sign of, 902 Thyrohyoid ligament calcification, 780, 784, 785 Thyroid calcific mass simulated in, 790 cartilage of calcification of, 781, 785, 786 osseous structure in cornua of, 169 superior cornua of calcification of, 780, 783 huge, 782 as separate ossicle, 781 Thyroid ligament calcification, 784, 785 Tibia bowing of, 508 distal end of, 617–637, 7S–219–7S–226 accessory ossification center for, 629, 630 closure of physes of, 620 epiphyseal plate of, 619, 620 epiphyses in, 619, 623, 624 flange on, 7S–219 malleolar ossicle of, 7S–222 maturation between fibula and, 620 medial malleolus in bifid, 7S–223 bony flanges on, 630 cleft, 623 closure failure of, 623 fracture simulated in, 7S–223 lucency in, 7S–222 ossicle of, 7S–222 ossification of, 627, 628

Tibia (Continued) ossification center for, accessory, 7S–222 ossification center for, secondary, 627, 628, 638 ossification center for, separate, 629 radiolucency in, 628 metaphyseal irregularity of, 617 mineralization irregularity in, 626 notch on, 621 os subtibiale in, 629 os trochleae calcanei and, 627 ossicle in posterior aspect of, 654 overlapping shadows of, 621 physeal position in, 618 physis of, 618 posterior malleolus in accessory ossification center for, 631 cortical undulations of, 7S–224 density in, 631 fossa on, 7S–223 Mach effect and, 7S–221 syndesmotic membrane calcification and, 7S–219 medial cortical thickening in, 534 medial plateau beaking in, 534 metaphyseal “fragmentation” of, 535 nutrient vascular channels of, 616 proximal ends of, 580–606, 7S–214–7S–217 anterior cortex thickening in, 596 anterior crest of, 596 defect in, 597 depressions in, 584 epiphyses of accessory ossification center for, 584 asymmetry of, 587 edge of, 7S–216 extension of into metaphysis, 586 fracture simulated in, 591 ganglion cyst in, 7S–215 intercondylar notch ossicle in, 583 lucency of eminence of, 583 metaphyses of accessory ossification centers for, 584 extension of epiphysis into, 586 medial, bulge in, 7S–217, 591 medial, cortical irregularity of, 589 medial, fossae at, 590 medial, spur at, 7S–217 radiolucency of, 596 shadows on, 593 overlapping of fibula on, 594 physeal shadow of, 593 ringlike lesions in proximal, 588, 589 spine in, 580 spurlike extensions of, 591 spurs on, 590 sulcus and, 592 tibial–fibular articulation and, 591 trabeculations on, 594 tubercle of apophyseal appearance variations in, 585 fossa for, 584 intraarticular loose body simulated by, 586 laminated appearance of, 595 open apophysis of, 592, 596 ossicle at fourth, 7S–214 ossification centers for, 7S–215, 585, 586 radiolucency of, 594 shadow of, 593 tibial depressions and, 584 tuberosity of, 594, 595 “tug” lesion of, 7S–217 shaft of, 607–616, 7S–218–7S–219

Tibia (Continued) bowing of, 607, 608, 609 cortical defects in examples of, 613 healed benign, 614 juvenile benign, 612, 615 cortical irregularities in, 609, 611 interosseous membrane of, 7S–218 periostitis of, 611, 612 transverse line of, 7S–218 vascular channels in, 612 Tibial plateau factitious radiolucencies of, 587 medial beaking of, 534 double contour of, 555 notch on, 590 spur on, 581, 582 Tibial spine, 580 Tibial–fibular articulation, 591 Tibialis anterior tendon, 703 Tibiofibular ligament, 625 Toe, 745–759, 7S–250 distal tuft absence in, 757 duplication anomaly of, 759 fat necrosis near joints of, 754 fifth cyst simulation by, 738 duplication of, 759 phalanx of duplication of middle, 753 irregularity of proximal, 755 with two phalanges, 756 first accessory ossification centers at base of, 745 clefts in in distal ends of, 711 epiphyseal, 747, 748, 749 epiphysis of, 751 fissure in, 7S–250 ossifications between spurs on, 754 phalanges of cleft in ossification center at base of, 746 distal, accessory bone of base of, 754 distal, configuration of base of, 751 distal, epiphyseal fusion failure at base of, 753 distal, excrescences of, 756 distal, spurlike enlargements of, 754 proximal, epiphyses of, 746, 747, 750 proximal, fissures through, 752 proximal, fossa at base of, 7S–250, 749, 750 proximal, ossicle in, 7S–250 proximal, pseudocysts of, 758 single ossification centers at base of, 747 nail bed of, 759 phalanges of developmental irregularity of, 753 distal, 755, 757 proximal cone epiphyses in, 751 fractures simulated in, 752, 755 irregularities on, 7S–250, 755 nutrient foramina of, 756 sclerosis in, 758 ringlike defects near joints of, 754 second cleft epiphysis of, 748 fissure in, 7S–250, 752 third, fissure in, 7S–250 with two phalanges, 757

Tongue air between hard palate and, 766 base of, in basal view of skull, 766 deep median sulcus of, 127 lingual tonsil and, 943 normal configuration of, 764 pharyngeal air shadow and, 2S–56 pharyngeal pseudomass and, 765 shadow of mandible and, 78 ossification center simulated by, 113 overlapping, 3S–73, 128 surface of, 765 Tonsil calcification in crypt of, 768 lingual, 943 pharyngeal, 1S–38, 767 pillar of, 3S–74 stone in, 768 Torus fracture simulation of by fibular bumps, 617 by phalanx tuberosities, 474 by tuberosity at base of metatarsals, 726 Towne’s projection anterior fontanel bone in, 11 C1 arches in, 3S–65, 3S–67 C2 arch in, 3S–67 mastoid emissary vein in, 1S–30 occipital bone in, 1S–20 Trabeculation calcaneal, 671, 681 of femoral necks, 497, 498, 499 of fifth metatarsal, 718 in hand, 6S–189 “herringbone” of humerus, 371 malleolar, 633 navicular cyst simulated by, 442 navicular fracture simulated by, 440, 441 scapular, 5S–149, 308, 311 speckled in the hand, 6S–189 of intertrochanteric area, 510, 511 of talus, 7S–231, 658 tibial, 594 Trachea anterior curve of, 860 azygos arch behind, 871 bifurcation of, 845 bowing of, 832 buckling of, 830, 831, 895 calcification of, 832 indentation in, 829, 831 mucus plugs in, 843 during respiration in adults, 774 in infants, 828, 829 with right aortic arch, 830 Tracheal cartilage calcification, 784, 785 Tracheobronchial cartilage, 832 Traction spur at acetabular margins, 280 Transitional vertebrae, 237 Transverse intermeniscal ligament, 552 Transverse ligament, 110 Transverse process. See also specific vertebrae. clavicle and, 5S–150 epitransverse process and, 92 nodular shadows produced by, 834 ossification centers for persistence of, 192 un-united, 3S–89 paracondylar process and, 88 “pig snout” pedicle and, 222 ptotic, 215

Index Transverse process (Continued) pulmonary nodule simulated by, 833, 835 of rib cavitary lung lesion simulated by, 5S–164 dislocation of simulated, 5S–165 elongated, 350 shadows of, 176 spinal, 351 superimposition of, 221 of thoracic spine, 3S–104 Transverse venous sinus, 47, 48 Trapezium, 435–437, 6S–181 accessory metacarpal arising from, 436 coalition of trapezoid and, 6S–181 configuration of, 449 first metacarpal and, 462 fusion of, 438 medial facet prolongation in, 436 osseous process arising from, 436 radial aspect of, 435 ring lesion in, 6S–181 Trapezium secundarium examples of, 6S–178, 421, 437, 462 location of, 414 simulated by hamulus process, 433 Trapezoid, 435–437, 6S–181 coalition of trapezium and, 6S–181 fusion of scaphoid and trapezium and, 438 hypoplasia of, 435 Traumatic sequelae, 6S–174 Triangular fibrocartilage injury, 6S–175 Triceps tendon sesamoid bone in, 390 tendinous calcification at insertion of, 6S–174 Trigeminal neuralgia, 56 Trigonal plate, 1049 Trigone, 1051 Triquetrum, 447–449, 6S–185 appearance of, 448 fusion of pisiform and, 6S–185, 454 lunate and accessory osseous element between, 449 coalition of, 425, 447 fusion of, 6S–185, 431, 447 os epipyramis and, 416 os epitriquetrum and, 416 ring lesions in, 448 ulnar styloid and, 6S–175 Triradiate cartilage, 4S–134, 265 Trochanter, 506, 7S–197–7S–198 apophyseal line of, 506 femoral neck radiolucencies and, 499 greater accessory ossification center for, 506 ossification irregularities in, 7S–197 shadow of, 7S–197, 7S–198 ossification centers for, 506 “tug” lesion below lesser, 7S–198 Trochlear process accessory bone arising from, 643 lucency produced by, 677 prominence of, 676, 677 Trough sign, 356 Tubercle. See also Tuberosity. geniohyoid, 81 lucencies of in ribs, 346 shadows of, 203 spinal anterior of transverse process, 175 elongation of anterior, 168 tibial apophysis of appearance variations of, 585 open-mouth view of, 592

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Tubercle (Continued) overlapping of open on fibular neck, 596 developing, 584 intraarticular loose body simulated by, 586 laminated appearance of, 595 ossicle at fourth, 7S–214 ossification centers for normal, 7S–215 separate un-united, 585 unfused, 586 radiolucency produced by, 594 shadow of simulating fracture, 593 of wrist navicular, 6S–184, 419 Tuberculum sella turcica, 1S–40, 64 Tuberosity. See also Tubercle. calcaneal accessory bones of, 643 developmental foramina in, 678 fossae in, 7S–234 irregularity of, 674 ossification centers for, 675 of forearm, 398 humeral greater cancellous bone and, 362 en face view of, 6S–168 fracture simulated in, 361 ossification centers for, 370 pseudocyst of, 363, 365 lesser, 363 of metatarsal apophysis of at base of, 714 ossification centers for, 715 torus fracture simulated by, 726 of phalanges, 474 tibial, 594, 595 Tubular blush, 1026, 1033 “Tug” lesion below lesser trochanter, 7S–198 femoral, 518, 519 fibular, 602, 603 iliac spine and, 263 at ischial apophyses, 4S–131, 271 at rectus femoris muscle insertion, 263 at soleus muscle origin, 602, 604 tibial, 7S–217 Turbinate air stripes in nasal, 83 antrum tumor simulation and, 2S–48, 72 inferior, 2S–61, 764 pneumatized middle nasal, 83 “Two-eyed Scotty dog,” 223

U Ulcer of colon, 992 colonic linear, 997 in duodenal bulb, 970, 971 mucosal in hepatic flexure, 991 simulation of by barium, 957 by gastric diverticulum, 962 by pyloric canal, 965 Ulcerative colitis, 986 Ulna accessory ossicles of, 410, 411 annular ligament and, 397 bone island in, 6S–172 bowing of, 401 cancellous bone of proximal ends of, 393 cleft styloid epiphysis of, 408 coronoid process of long, 397

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Index

Ulna (Continued) ossicle at tip of, 6S–173 ossification center for, 6S–173, 396 cortical tunneling of, 400 developmental fossa in, 403 deviation of with navicular–lunate interval, 444, 445 with normal navicular, 443 dislocation of, 404 epiphyses of cartilage spicules in, 6S–175, 406 cleft, 408 lucencies of, 410 foramina for nutrient vessels of, 392 fossae in, 397 interosseous ridges of, 399 long, 403 Madelung’s deformity and, 423 physis of closure of, 407 extension of metaphysis into, 407 short, 6S–174 simulated fracture of, 391 styloid process of configuration of, 412 ossicle of, 412 ossification centers for, 411 ring shadow on, 413 rotary subluxation and, 6S–183 size of, 412, 413 ulna plus variant and, 6S–175 trabeculations in shaft of, 391 Ulna minus variant, 6S–174, 401 Ulna plus variant, 6S–175, 403 Ulnar impaction syndrome, 6S–175 Umbilical artery, 942 Umbilicus, 939 Unciform process cyst simulated by, 432 elongated hamate, 432, 433 ossification of, 434 wrist with separate, 434 Uncinate process, 131 Uncovertebral process, 132 Ungual tuft, 6S–189 Upper extremity, 354–484, 6S–166–6S–190 Ureter, 1039–1046 asymmetry of pelvic, 1045 configuration of, 1041, 1045 course of, 1039 deviations of, 1039, 1044, 1045 displacement of, 1042 duplication of, 1044 ectopic, 1045 filling defect in, 1046 full column filling of, 1040 longitudinal striations in, 1039 medial deviation of, 1042, 1043 pathologic changes in, 1040 peristalsis of, 1040 periureteral fat and, 1010, 1041 positional variations of, 1040 retrocaval, 1041 of retroiliac artery, 1041 transverse folds in, 1039 Ureteral jet phenomenon, 1045 Urethra, 1052–1055 calculi of, 1055 distended, 1053 finger pressure, 1054 intermuscular incisurae of, 1052, 1053 plicae colliculi of, 1052 prostatic, 1052

Urethra (Continued) sphincter of, 1053, 1054 “spinning top,” 1054 Urethral distention, 1049 Uterus arcuate, 1056 arterial calcification in, 1014 bladder and, 1007, 1049 contour of, 1056 duplication of, 1056 endocervical glands of, 1056 fundus of, 1056 infantile in adult, 1056 lumen of, 1056 myometrial folds of, 1056 variants of, 1056 Uterus didelphys, 1056 Uvula in nasopharyngeal air shadow, 63 shadow of, 767 soft palate and, 766

V “Vacuum” phenomenon of cervical intervertebral disc injury, 3S–85 in hip, 491 in knee joint, 555 in sacroiliac joints, 255 in shoulder joint, 310 in symphysis pubis, 4S–133 in wrist, 6S–177 Vagina barium in, 998 duplication of, 1056 extravasation of, 998 residue from, 1055 septum of, 1056 Valsalva maneuver, 859, 876 Valvulae conniventes, 973 Varix of inferior vena cava, 900 Vascular calcification costal cartilage calcification simulating, 353 in plantar soft tissues, 682 Vascular channel button sequestra simulation by, 6 in calvaria, 1S–2, 8 of fibula, 616 in frontal bone, 1S–10, 1S–11, 30 above frontal sinuses, 29 of lumbar vertebral body, 205 for the middle temporal artery, 52 normal, 7 in occipital bone, 1S–21 in parietal bone, 1S–13, 1S–28 pseudofractures produced by, 128 scapular, 5S–149, 309 sclerotic band resulting from, 206 in skull vertex, 1S–37 in temporal bone, 1S–28, 52 tibial, 612, 616 Vascular foramina, 6S–179, 428 Vascular groove. See Vascular channel. Vascular necrosis, 7S–193 Vascular pattern, parietal, 6, 7, 36 Vascular stripe in thoracic spine, 190 Vascular trunk division patterns, 828 Vastus lateralis muscle femoral insertion of, 519 femoral “tug” lesions and, 7S–201 origin of, 509, 510 Vastus medialis muscle, 7S–201

Veins of Santorini, 34 Vena cava inferior absence of, 874 adjacent to heart border, 899 atrial shadow and, 899 dilatation of, 900 hiatal hernia simulated by, 840 interruption of, 889 pleural reflection over, 813, 822 radiolucencies produced by, 900 shadow of atelectasis simulated by, 901 lung and, 885 prominent, 898 ureter coursing around, 1041 varix of, 900 wide, 862 superior dilatation of, 897, 898 displacement of, 896 distension of, 859 examples of, 896 Venous channel, 1S–22 Venous groove, 36 Venous lake occipital, 1S–21, 1S–22, 46 parietal thinning and, 36 Venous plexus, 944 Venous sinus neonatal thoracic spine and, 189 occipital external protuberance and, 1S–26 location of, 1S–24 prominent, 1S–23 in thoracic spine, 191 residual “holes” of, 190 transverse, 2S–43 Venous thrombus calcification, 1008, 1015 Venous vascular marking, 36 Ventral submucosal venous plexus, 944 Ventricular hypertrophy, 879 Vertebra. See specific vertebra; spinal areas. Vertebral artery arcuate foramina and, 93, 98 C2 pedicles and, 3S–79 Vertebral compression fracture, 200 Vertebral “slipping,” 148 Verumontanum, 1053 Voiding forceful, 1053 intravaginal, 1055 in males, 1054 Volvulus, 980 Vulvar phleboliths, 1014

W Ward’s triangle, 496 Waters’ projection foramina ovale in, 1S–37 inferior turbinate in, 2S–61 infraorbital foramina in, 62 nasal bone fracture simulated in, 2S–60 parietal bone and, 5 serous cyst simulation and, 2S–49 “Wave” sign, 902 Well-corticated ossicle, 60 “White line” of femoral neck, 503 Wormian bones, 1S–3, 1S–28, 12

Wrist flexion of, 426 ossicle on, 448 with separate unciform process, 434 spurlike projection on, 448 “vacuum” phenomenon in, 6S–177

X Xiphoid process accessory center for, 5S–155 configuration of, 330, 333, 334 flexion of, 332 sternum and, 331, 332

Index Y “Yo-yo” effect, 1038

Z Zygomatic arch, 78, 2S–55 overlapping shadows in, 78 sphenoid sinus and, 2S–53 suture between zygomatic bone and, 2S–55, 78 Zygomatic bone, 2S–55, 78 Zygomatic orbital processes, 69

Zygomatic process, 2S–55, 78 Zygomaticofrontal suture in a neonate, 12 orbital fracture simulated by, 69 Zygomaticotemporal foramen, 2S–55 Zygomaxillary suture, 2S–55

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