(Herring) Learning Radiology - Recognizing the Basics
Use of the current edition of the electronic version of this book (eBook) is subject to the terms of the nontransferable, limited license granted on studentconsult.inkling.com. Access to the eBook is limited to the first individual who redeems the PIN, located on the inside cover of this book, at studentconsult.inkling.com and may not be transferred to another party by resale, lending or other means. Unlock your eBook today. 1 Visit studentconsult.inkling.com/redeem 2 Scratch off your code 3 Type code into “Enter Code” box 4 Click “Redeem” 5 Log in or Sign Up 6 Go to “My Library” It’s that easy! Student Consult eBooks give you the power to browse and find content, view enhanced images, share notes and highlights—both online and offline. For technical assistance: email studentconsult.help@elsevier.com call 1-800-401-9962 (inside the US) call +1-314-447-8200 (outside the US) Any screen. Any time. Anywhere. Activate the eBook version of this title at no additional charge. Scan this QR code to redeem your eBook through your mobile device: Place sticker here. Learning Radiology This page intentionally left blank William Herring, MD, FACR Vice Chairman and Residency Program Director Albert Einstein Medical Center Philadelphia, Pennsylvania Learning Radiology RECOGNIZING THE BASICS 3rd EDITION 1600 John F. Kennedy Blvd. Ste 1800 Philadelphia, PA 19103-2899 LEARNING RADIOLOGY: RECOGNIZING THE BASICS, 3rd EDITION ISBN: 978-0-323-32807-4 Copyright © 2016, 2012, 2007 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 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 and 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 Herring, William, author. Learning radiology : recognizing the basics / William Herring.—3rd edition. p. ; cm. Includes bibliographical references and index. ISBN 978-0-323-32807-4 (paperback : alk. paper) I. Title. [DNLM: 1. Radiography—methods. 2. Diagnosis, Differential. WN 200] R899 616.07′572—dc23 2015006990 Senior Content Strategist: James Merritt Content Development Specialist: Katy Meert Publishing Services Manager: Anne Altepeter Senior Project Manager: Doug Turner Designer: Xiaopei Chen Printed in the United States of America Last digit is the print number: 9 8 7 6 5 4 3 2 1 To my wife, Patricia, And our family This page intentionally left blank vii Daniel J. Kowal, MD Computed Tomography Division Director Radiology Elective Director Department of Radiology Saint Vincent Hospital Worcester, Massachusetts Chapter 22: Magnetic Resonance Imaging: Understanding the Principles and Recognizing the Basics Contributor This page intentionally left blank ix I’ve checked, and most prefaces to a third edition or later start out with something like, “It’s hard to believe that this is the third edition of…” Not this text. I know how much work it’s taken, so I definitely can believe it. But thank you if you have contrib uted in any way, including reading this preface, to the success of this book. In the first edition, I asked you to suppose for a moment that your natural curiosity drove you to wonder what kind of bird with a red beak just landed on your window sill. You could get a book on birds that listed all of them alphabetically from albatross to woodpecker and spend time looking through hundreds of bird pictures. Or you could get a book that lists birds by the colors of their beaks and thumb through a much shorter list to find that your feathered visitor is a cardinal. This book is a red beak book. Where possible, groups of diseases are first described by the way they look rather than by what they’re called. Imaging diagnoses frequently, but not always, rest on a recognition of a reproducible visual picture of that abnormality. That is called the pattern recognition approach to identifying abnormalities, and the more experience you have looking at imaging studies, the more comfortable and confident you’ll be with that approach. Before diagnostic images can help you decide what disease the patient may have, you must first be able to differentiate between what is normal in appearance and what is not. That isn’t as easy as it may sound. Recognizing the difference between normal and abnormal probably takes as much practice, if not more, than deciding what disease a person has. Radiologists spend their entire lives performing just such differentiations. You won’t be a radiologist after you’ve com pleted this book, but you should be able to recognize abnor malities and interpret images better and, by so doing, perhaps participate in the care of patients with more assurance and confidence. When pattern recognition doesn’t work, this text will try wherever possible to give you a logical approach to reaching a diagnosis. By learning an approach, you’ll have a method you can apply to similar problems again and again. An analytic approach will enable you to apply a rational solution to diagnostic imaging problems. This text was written to make complimentary use of the platform on which radiologic images are now almost universally viewed: the digital display. Although digital displays may be ideal for looking at images, some people do not want to read large volumes of text from their digital devices. So we’ve joined the text in the printed book with photos, videos, quizzes, and tutorials—many of them interactive—and made them available online at StudentConsult/Inkling.com in a series of web enhancements that accompany the book. I think you’ll really enjoy them. This text is not intended to be encyclopedic. Many wonderful radiology reference texts are available, some of which contain thousands of pages and weigh slightly less than a Mini Cooper. This text is oriented more toward students, interns, residents, residents-to-be, and other health care professionals who are just starting out. This book emphasizes conventional radiography because that is the type of study most patients undergo first and because the same imaging principles that apply to reaching the diagnosis on conventional radiographs can frequently be applied to making the diagnosis on more complex modalities. Let’s get started. Or, if you’re the kind of person (like I am) who reads the preface after you’ve read the book, I hope you enjoyed it. William Herring, MD, FACR Preface This page intentionally left blank xi I am again grateful to the many thousands of you whom I have never met but who found a website called Learning Radiology helpful, making it so popular that it played a role launching the first edition of this book, which itself was so popular that it led to this third edition. For their help and suggestions, I thank David Saul, MD, one of our radiology residents, who made invaluable suggestions about how this edition could be changed. Daniel Kowal, MD, a radiologist who graduated from our program, did an absolutely wonderful job in simplifying the complexities of MRI again in the chapter he wrote. Jeffrey Cruz, MD, one of our residents, helped out with the online Radiation Safety and Dose module, and Sherif Saad, MD, contributed an illustration. I thank Chris Kim, MD; Susan Summerton, MD; Mindy Horrow, MD; Peter Wang, MD; and Huyen Tran, MD, for supplying additional images for this edition. And thanks to Mindy Horrow, MD; Eric Faerber, MD; and Brooke Devenney- Cakir, MD, for reviewing chapters from this text. I certainly want to recognize and again thank Jim Merritt and Katy Meert from Elsevier for their support and assistance. I also acknowledge the hundreds of radiology residents and medical students who, over the years, have provided me with an audience of motivated learners, without whom a teacher would have no one to teach. Finally, I want to thank my wonderful wife, Pat, who has encouraged me throughout the project, and my family. Kowal, MD How Magnetic Resonance Imaging Works 220 Hardware That Makes Up an MRI Scanner 220 What Happens Once Scanning Begins 220 How Can You Identify a T1-Weighted or T2-Weighted Image?
-
-