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Problem Solving in Emergency Radiology Stuart E. Mirvis, MD, FACR Professor Department of Diagnostic Radiology and Nuclear Medicine University of Maryland School of Medicine Baltimore, Maryland Wayne S. Kubal, MD Professor of Medical Imaging Department of Medical Imaging University of Arizona Tucson, Arizona Kathirkamanathan Shanmuganathan, MD Professor of Radiology Department of Diagnostic Radiology and Nuclear Medicine University of Maryland School of Medicine Baltimore, Maryland Jorge A. Soto, MD Professor of Radiology Boston University School of Medicine Vice Chairman Department of Radiology Boston Medical Center Boston, Massachusetts Joseph S. Yu, MD Professor of Radiology and Orthopedic Surgery Vice Chair of Academic Affairs and Education The Ohio State University Wexner Medical Center Columbus, Ohio tahir99 - UnitedVRG vip.persianss.ir 1600 John F. Kennedy Blvd. Ste 1800 Philadelphia, PA 19103-2899 PROBLEM SOLVING IN EMERGENCY RADIOLOGY ISBN: 978-1-4557-5417-5 Copyright © 2015 by Saunders, an imprint of Elsevier Inc. All rights reserved. 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 evaluat- ing 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 Problem solving in emergency radiology / section/associate editors, Stuart Mirvis, Wayne S. Kubal, Kathirkamanathan Shanmuganathan, Jorge A. Soto, Joseph S. Yu. p.; cm. Includes bibliographical references and index. ISBN 978-1-4557-5417-5 (hardcover : alk. paper) I. Mirvis, Stuart E., editor of compilation. II. Kubal, Wayne Scott, editor of compilation. III. S hanmuganathan, K. (Kathirkamanathan), editor of compilation. IV. Soto, Jorge A., editor of compilation. V. Yu, Joseph, editor of compilation. [DNLM: 1. Diagnostic Imaging. 2. Emergencies. WN 180] RC78 616.07’57--dc23 2013046612 Senior Content Strategist: Don Scholz Content Development Specialist: Julia Rose Roberts Publishing Services Manager: Anne Altepeter Project Manager: Ted Rodgers Designer: Steven Stave Printed in China Last digit is the print number: 9 8 7 6 5 4 3 2 1 tahir99 - UnitedVRG vip.persianss.ir To Linda, for her patience and understanding, and Zack, who always makes me smile Stuart Mirvis To my parents, Fred and Lillian, who gave me the love and support to believe that all things are possible Wayne Kubal To my parents and sister, Nalayini Shan, who are always available for moral support and advice when required Kathirkamanathan Shanmuganathan To my wife, Ana; my daughter, Andrea; and my son, Alejandro Jorge Soto To Cynthia and Sarah, the two anchors of my life Joseph Yu tahir99 - UnitedVRG vip.persianss.ir Foreword Today’s emergency departments (EDs) are emergency Analogous to the critical role emergency medicine plays diagnostic centers. Of the 130 million patients who cur- in delivering clinical care and coordinating diverse rently visit an ED each year in the United States, nearly medical and surgical specialties in the ED, emergency half will have some type of imaging performed, mak- radiology sections are postured to resolve the care frag- ing it clear that imaging has become an indispensable mentation that typically plagues imaging services pro- tool for diagnosing acute conditions and traumatic vided by remote silos of organ- and modality-based injuries in this setting. But it is computed tomography radiology specialties. For better or worse, such change (CT) imaging in particular that has thrust imaging to the in radiology practice remains mostly evolutionary rather forefront of emergent care. The diagnostic use of CT in than revolutionary. the ED increased 330% between 1996 and 2007, from Dedicated emergency radiology sections first emerged 3% to 14% of all patient visits. There was a widespread in a few academic medical centers during the 1980s and increase in the use of CT for the 20 most common ED 1990s. Although this care model was initially met with chief complaints. Within this context, the matured spe- institutional inertia, in the past decade it has been more cialties of emergency medicine and trauma surgery, widely adopted, especially in large medical centers or and modern health care in general, have placed great multihospital systems with sufficient ED visits and/or emphasis on contemporaneous imaging interpretation. Level 1 trauma services. Despite the growth in adoption Together, these forces have transformed the radiolo- of dedicated emergency radiology sections, resident gist’s role from minor participant to major player in care and fellow interpretations remain a mainstay of “after- delivery and in so doing have given birth to the ascen- hours” coverage for many radiology departments with dant specialty of emergency radiology. Indeed, the need training programs. At smaller-scale institutions and in to provide coordinated radiologic care contemporane- private practice, the growth in ED imaging, coincident ous to the ED patient visit has never been greater. This with advances in computing technology and network is why this book is such an important and timely contri- speeds, resulted in a different course. During the 1980s bution to the specialty. and 1990s most community radiology practices pro- Radiologists who provide coverage of ED imag- vided coverage of after-hours ED imaging from home ing require a broad fund of knowledge spanning most using web-based viewers rather than sophisticated tele- imaging modalities and organ systems. Although his- radiology solutions. As the demand for this imaging torically such practice has been characterized as general dramatically increased during the mid to late 1990s, a radiology, this term is now anachronistic and anath- commercial market emerged for outsourced teleradiol- ema to practicing emergency radiologists. Instead, the ogy services. By 2007 a majority of private practice radi- required interpretational expertise is defined by the ology groups used such services. common conditions affecting acutely ill or traumatized Although today’s approach to coverage of ED imaging patients. Epidural hematoma, cervical spine fracture, remains heterogeneous, it appears certain that greater aortic injury, liver laceration, stroke, aortic dissection, emphasis will continue to be placed on the value, time- pulmonary embolus, pneumonia, appendicitis, diver- liness, and coordination of radiologic care provided. ticulitis, bowel obstruction, ectopic pregnancy, tubo- Advocating for optimal radiologic care of the ED patient ovarian abscess, osteomyelitis, and the like define the has been the core mission of the American Society of field of emergency radiology. Emergency Radiology (ASER). Founded in 1988, ASER Equally important, the skills required for optimal has worked to advance the quality of diagnosis and radiologic care in the ED extend well beyond interpre- treatment of acutely ill or injured patients by means of tational expertise, particularly if that expertise is largely medical imaging and to enhance teaching and research defined by a single organ system or imaging modal- in emergency radiology. In the quarter century since its ity. Surely no one is convinced that optimal care for a founding, ASER has grown from its 8 founders (Drs. severely traumatized patient transferred from an outside Gordon C. Carson, John H. Harris, Jr., Alan Klein, Jack P. institution is achieved by seeking interpretations from Lawson, James J. McCort, Stuart E. Mirvis, Charles F. multiple organ-based subspecialties remote from the Mueller, and Robert A. Novelline) and 16 charter mem- ED. Contemporaneous clinical consultation, appropri- bers to more than 900 members. ASER and its members ateness oversight, examination protocol optimization, have worked tirelessly to establish emergency radiology resource triage, image and radiation dose management as a specialty within organized radiology. A successful across organ systems, and using the range of imaging peer-reviewed journal (Emergency Radiology), annual modalities are required to optimize ED patient out- society meetings, a core educational curriculum for radi- comes; these define the role of an emergency radiologist. ology trainees, a high-quality website (www.erad.org), When such requirements are coupled with the 24/7 and equal representation alongside other radiology spe- operations and time-sensitive obligations inherent cialties in important professional venues (for example, in caring for ED patients, the most common legacy the Radiological Society of North America [RSNA], approaches to ED coverage often fall short in achieving the American Roentgen Ray Society [ARRS], and the a consistent standard of care, let alone an optimal one. American College of Radiology [ACR]), are testaments tahir99 - UnitveidiVRG vip.persianss.ir viii Foreword to the Society’s success. International members also its most lofty goal, which is to more clearly define and have made significant contributions to ASER and have broadly disseminate the body of knowledge that defines helped disseminate the practice of emergency radiology emergency radiology practice today. Given Dr. Mirvis’s at the global level. New emergency radiology societies lifelong devotion to and stature within the field of have been established outside the United States, most emergency radiology, from founding member of ASER recently in Europe and Asia. For ASER leaders and many to leading international authority on trauma and note- practicing emergency radiologists in the United States worthy journal editor, there is no better steward of this and abroad, the past 2 to 3 years have symbolized a tip- worthy ambition. ping point toward the realization of our greater ambi- This book will have broad appeal to many audiences. tions: full recognition as a specialty within the pantheon It will prove an invaluable resource to any practicing of radiology. radiologist providing coverage of emergency department At this pivotal time for emergency radiology, it is imaging, regardless of whether or not the radiologist important that a single text captures the core knowl- self-identifies as an emergency radiologist. It is required edge that defines this modern specialty. Problem Solving reading for every diagnostic radiology resident or fellow in Emergency Radiology represents the most up-to-date and will be of great interest to emergency medicine phy- and comprehensive contribution from many leading sicians, trauma surgeons, and the many other physicians authors in this field. Supported by ASER and edited by and care providers who consult on patients in the ED. Dr. Mirvis, this text draws upon a large variety of exper- Dr. Mirvis and colleagues have assembled what is sure to tise across the broad range of emergency imaging top- become the new reference text on emergency radiology. ics. Using a “head-to-toe” organizational approach, with sections based on anatomic regions and subdivi- Stephen Ledbetter, MD, MPH sion by traumatic and nontraumatic presentations, the Chief of Radiology text is well organized for rapid access to any relevant Brigham and Women’s Faulkner Hospital topic and easily serves as a companion to the ASER Boston, Massachusetts core curriculum. Most important, the book achieves tahir99 - UnitedVRG vip.persianss.ir Preface Problem Solving in Emergency Radiology is one of a series conditions, to present recent terminology, to offer a of texts published by Elsevier starting in 2007 that are generous quantity of up-to-date imaging with postpro- intended to provide core reviews of major areas of diag- cessing enhancement, to show and discuss confusing nostic imaging, focusing on what the authors believe are variants that simulate pathologic conditions and atypi- the most relevant, up-to-date concepts in the areas of their cal presentations of common emergency pathologic expertise, as well as to provide practical knowledge to conditions, and to expose the reader to rarely encoun- help in negotiating complex cases and unusual imaging tered emergency imaging diagnoses. presentations of acute pathologic conditions and in dis- One difficulty encountered in multiauthored text- tinguishing actual from “pseudo” pathologic conditions. books is maintaining a consistent writing style and a This text is divided into five sections representing major similar level of detail in coverage of the subject. Different anatomic areas. Each section was prepared by a coeditor, writing styles, chapter length limitations, and multiple including Joseph S. Yu, MD (Musculoskeletal Emergen- chapter contributors create this variation. It is our hope cies), Stuart E. Mirvis, MD, FACR (Thoracic Emergency that readers can navigate these differences in chapter Radiology), Wayne S. Kubal, MD (Spine Emergen cies, Cra- structure to glean the core information provided within. niocerebral and Orbital-Maxillo-Facial Emerg encies), and The chapters review major regional imaging anatomy, Kathirkamanathan Shanmuganathan, MD (Blunt Abdom- clinical concepts germane to the topic, and the applica- inal and Retroperitoneal Trauma) and Jorge A. Soto, MD tion of various imaging modalities and their strengths (Nontraumatic Abdominal Emergen cies) sharing the and limitations where appropriate. The authors attempt work of the section on Abdominal Emergencies. The book to provide a basic foundation for imaging emergent starts with overview chapters on strategies for computed pathologic conditions to address the needs of radiolo- tomography radiation reduction in the acute care setting gists in training, as well as to provide advanced concepts, by Aaron Sodickson, MD, PhD, and image management detailed information, subtle findings, and challenging in emergency radiology by Martin L. Gunn, MBChB, cases for the more seasoned radiologist. FRANZCR, and Jeffrey D. Robinson, MD. Both chapters In addition to imaging specialists, physicians special- have general application in all aspects of emergency imag- izing in emergency medicine, critical care and internal ing. There are 88 contributors to the text, offering a wide medicine, and emergent surgical conditions will find spectrum of information covering a huge number of topics an understandable, clinically relevant, timely, and com- in emergency radiology. prehensive text to gain new or refresh prior knowledge The goal of this text is to bring together in one book that is essential to diagnosis and planning treatment of both traumatic and nontraumatic imaging findings of acutely ill or injured patients. emergency radiology. Some of our goals were to provide an update on imaging techniques, to review the evolving Stuart E. Mirvis, MD, FACR scoring (grading) systems for trauma and nontraumatic tahir99 - UniteixdVRG vip.persianss.ir