The Essential Physics of Medical Imaging, 3rd Edition T H I R D E D I T I O N JERROLD T BUSHBERG, PhD Clinical Professor of Radiology and Radiation Oncology University of California, Davis Sacramento,.
The Essential Physics of Medical Imaging THIRD EDITION JERROLD T BUSHBERG, PhD Clinical Professor of Radiology and Radiation Oncology University of California, Davis Sacramento, California J ANTHONY SEIBERT, PhD Professor of Radiology University of California, Davis Sacramento, California EDWIN M LEIDHOLDT JR, PhD Clinical Associate Professor of Radiology University of California, Davis Sacramento, California JOHN M BOONE, PhD Professor of Radiology and Biomedical Engineering University of California, Davis Sacramento, California Executive Editor: Charles W Mitchell Product Manager: Ryan Shaw Vendor Manager: Alicia Jackson Senior Manufacturing Manager: Benjamin Rivera Senior Marketing Manager: Angela Panetta Design Coordinator: Stephen Druding Production Service: SPi Global Copyright © 2012 by LIPPINCOTT WILLIAMS & WILKINS, a WOLTERS KLUWER business Two Commerce Square 2001 Market Street Philadelphia, PA 19103 USA LWW.com 2nd edition © 2002 by LIPPINCOTT WILLIAMS & WILKINS 1st edition © 1994 by LIPPINCOTT WILLIAMS & WILKINS All rights reserved This book is protected by copyright No part of this book may be reproduced in any form by any means, including photocopying, or utilized by any information storage and retrieval system without written permission from the copyright owner, except for brief quotations embodied in critical articles and reviews Materials appearing in this book prepared by individuals as part of their official duties as U.S government employees are not covered by the above-mentioned copyright Printed in China Library of Congress Cataloging-in-Publication Data Bushberg, Jerrold T The essential physics of medical imaging / Jerrold T Bushberg — 3rd ed p ; cm Includes bibliographical references and index ISBN 978-0-7817-8057-5 Diagnostic imaging. Medical physics. I Title [DNLM: Diagnostic Imaging—methods. WN 200] RC78.7.D53E87 2011 616.07'54—dc22 2011004310 Care has been taken to confirm the accuracy of the information presented and to describe generally accepted practices However, the authors, editors, and publisher are not responsible for errors or omissions or for any consequences from application of the information in this book and make no warranty, expressed or implied, with respect to the currency, completeness, or accuracy of the contents of the publication Application of the information in a particular situation remains the professional responsibility of the practitioner The authors, editors, and publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accordance with current recommendations and practice at the time of publication However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any change in indications and dosage and for added warnings and precautions This is particularly important when the recommended agent is a new or infrequently employed drug Some drugs and medical devices presented in the publication have Food and Drug Administration (FDA) clearance for limited use in restricted research settings It is the responsibility of the health care provider to ascertain the FDA status of each drug or device planned for use in their clinical practice To purchase additional copies of this book, call our customer service department at (800) 638-3030 or fax orders to (301) 223-2320 International customers should call (301) 223-2300 Visit Lippincott Williams & Wilkins on the Internet: at LWW.com Lippincott Williams & Wilkins customer service representatives are available from 8:30 am to pm, EST 10 9 8 7 6 5 4 3 2 First and foremost, I offer my most heartfelt love, appreciation and apology to my wife Lori and our children, Alex and Jennifer, who endured my many absences to focus on completing this text with “almost” infinite patience (especially during the last months, when I was typically gone before they woke and got home long after they had gone to sleep) I look forward to spending much more time with my family and even to starting to make a dent in the list of “chores” my wife has been amassing in my absence I have also had the good fortune to be supported by my extended family and my Oakshore neighbors who never missed an opportunity to offer an encouraging word after my response to their question “Is the book done yet?” Second, I would like to express my profound gratitude to my coauthors, colleagues, and friends Tony, Ed, and John for their herculean efforts to bring this 3rd edition into existence Not only would this text not exist without them, but the synergy of their combined skills, expertise, and insights was an invaluable resource at every stage of development of this edition We all have many more professional obligations now than during the writing of the previous editions The willingness and ability of my coauthors to add another substantial commitment of time to their already compressed professional lives were truly remarkable and greatly appreciated While all of my staff and colleagues have been very helpful and supportive during this effort (for which I am very grateful), two individuals deserve special recognition Linda Kroger’s willingness to proof read several chapters for clarity along with the countless other ways she provided her support and assistance during this effort with her typical intelligent efficiency was invaluable and greatly appreciated Lorraine Smith has been the coordinator of our annual radiology resident physics review course for as long as I can remember This course would not be possible without her considerable contribution to its success Lorraine is one of the most helpful, resourceful, patient, and pleasant individuals I have ever had the pleasure to work with Her invaluable assistance with this course, from which this book was developed, is gratefully acknowledged and deeply appreciated I would also like to thank our publisher Lippincott Williams and Wilkins, Charley Mitchell, Lisa McAllister, and in particular Ryan Shaw (our editor) for the opportunity to develop the 3rd edition Your patience, support, and firm “encouragement” to complete this effort are truly appreciated I dedicate this edition to my parents My mother, Annette Lorraine Bushberg (1929–1981), had a gift for bringing out the best in me She cheered my successes, reassured me after my failures, and was an unwavering source of love and support My father, Norman Talmadge Bushberg, brightens everyone’s world with his effortless wit and sense of humor In addition to his ever present love and encouragement, which have meant more to me than I can find the words to fully express, he continues to inspire me with his belief in each person’s ability and responsibility to make a unique contribution To that end, and at the age of 83, he recently published his first literary contribution, a children’s story entitled “Once Upon a Time in Kansas.” It is slightly lighter reading than our text and I highly recommend it However, if getting your child to fall asleep is the problem, then any chapter in our book should the trick J.T.B Thanks, TSPOON, for your perseverance, patience, and understanding in regard to your often AWOL dad during these past several years—it’s very gratifying to see you prosper in college, and maybe someday you will be involved in writing a book as well! And to you, Julie Rainwater, for adding more than you know to my well-being and happiness J.A.S To my family, especially my parents and my grandmother Mrs Pearl Ellett Crowgey, and my teachers, especially my high school mathematics teacher Mrs Neola Waller, and Drs James L Kelly, Roger Rydin, W Reed Johnson, and Denny D Watson of the University of Virginia To two nuclear medicine physicists, Drs Mark W Groch and L Stephen Graham, who contributed to earlier editions of this book, but did not live to see this edition And to Jacalyn Killeen, who has shown considerable patience during the last year E.M.L Susan Fris Boone, my wife, makes life on this planet possible and her companionship and support have made my contribution to this book possible Emily and Julian, children extraordinaire and both wild travelers of the world, have grown up using earlier editions of this book as paperweights, lampstands, and coasters I appreciate the perspective Marion (Mom) and Jerry (Dad) passed in the last few years, but the support and love they bestowed on me over their long lives will never be forgotten Sister Patt demonstrated infinite compassion while nurturing our parents during their final years and is an angel for all but the wings Brother Bob is a constant reminder of dedication to patient care, and I hope that someday he and I will both win our long-standing bet Friends Steve and Susan have elevated the fun in life My recent students, Nathan, Clare, Shonket, Orlando, Lin, Sarah, Nicolas, Anita, and Peymon have helped keep the flag of research flying in the laboratory, and I am especially in debt to Dr Kai Yang and Mr George Burkett who have helped hold it all together during my too frequent travel There are many more to thank, but not enough ink This book was first published in 1994, and over the many years since, I have had the privilege of sharing the cover credits with my coauthors and good friends Tony, Jerry, and Ed This has been a wild ride and it would have been far less interesting if not shared with these tres amigos J.M.B Preface to the Third Edition The first edition of this text was written in 1993, and the second edition followed in 2002 This third edition, coming almost 10 years after the second edition, reflects the considerable changes that have occurred in medical imaging over the past decade While the “digitization” of medical images outside of nuclear medicine began in earnest between the publication of the first and second editions, the transformation of medical imaging to an all-digital environment is largely complete at the time of this writing Recognizing this, we have substantially reduced the treatment of analog modalities in this edition, including only a short discussion on screen-film radiography and mammography, for example Because the picture archiving and communication system (PACS) is now a concrete reality for virtually all radiological image interpretation, and because of the increasing integration between the radiology information systems (RISs), the PACS, and the electronic medical record (EMR), the informatics section has been expanded considerably There is more to know now than 10 years ago, so we reduced some of the detail that existed in previous editions that may be considered nonessential today Detailed discussions of x-ray tube heating and cooling charts, three-phase x-ray generator circuits, and CT generations have been shortened or eliminated The cumulative radiation dose to the population of the United States from medical imaging has increased about sixfold since 1980, and the use of unacceptably large radiation doses for imaging patients, including children, has been reported In recent years, radiation dose from medical imaging and radiation therapy has become the focus of much media attention, with a number of radiologists, radiobiologists, and medical physicists testifying before the FDA and the U.S Congress regarding the use of radiation in imaging and radiation therapy The media attention has given rise to heightened interest of patients and regulatory agencies in the topics of reporting and optimizing radiation dose as well as limiting its potentially harmful biological effects In this edition, we have added an additional chapter devoted to the topic of x-ray dose and substantially expanded the chapters on radiation biology and radiation protection The current International Commission on Radiological Protection system of estimating the potential detriment (harm) to an irradiated population; the calculation of effective dose and its appropriate use; as well as the most recent National Academy of Sciences Biological Effects of Ionizing Radiation (BEIR VII) report recommended approach of computing radiation risk to a specific individual are discussed in several chapters Our publisher has indicated that the second edition was used by increasing numbers of graduate students in medical imaging programs While the target audience of this text is still radiologists-in-training, we have added appendices and other sections with more mathematical rigor than in past editions to increase relevance to scientistsin-training The goal of providing physicians a text that describes image science and the radiological modalities in plain English remains, but this third edition contains an appendix on Fourier transforms and convolution, and Chapter covers basic image science with some optional mathematics for graduate student readers and for radiologists with calculus-based undergraduate degrees v vi Preface to the Third Edition A number of new technologies that were research projects 10 years ago have entered clinical use, and this edition discusses the more important of these: tomosynthesis in mammography, cone beam CT, changes in mammography anode composition, the exposure index in radiography, flat panel fluoroscopy, rotational CT on fluoroscopy systems, iterative reconstruction in CT, and dual modality imaging systems such as PET/CT and SPECT/CT Some new technologies offer the possibility of substantially reducing the radiation dose per imaging procedure All of the authors of this book are involved in some way or another with national or international advisory organizations, and we have added some perspectives from published documents from the American Association of Physicists in Medicine, the National Council on Radiation Protection and Measurements, the International Commission on Radiation Units and Measurement, and others Lastly, with the third edition we transition to color figures, tables, text headings, and photographs Most of the figures are newly designed; some are colorized versions of figures from previous editions of the text This edition has been completely rewritten and a small percentage of the text remains as it was in previous editions We hope that our efforts on this third edition bring this text to a completely up-to-date status and that we have captured the most important developments in the field of radiology so that the text remains current for several years to come Foreword Dr Bushberg and his coauthors have kept the title The Essential Physics of Medical Imaging for this third edition While the first edition in 1994 contained the “essentials,” by the time the second edition appeared in 2002, the book had expanded significantly and included not only physics but also a more in depth discussion of radiation protection, dosimetry, and radiation biology The second edition became the “go to” reference book for medical imaging physics While not light weekend reading, the book is probably the only one in the field that you will need on your shelf Residents will be happy to know that the third edition contains the topics recommended by the AAPM and thus likely to appear on future examinations Although there are shorter books for board review, those typically are in outline form and may not be sufficient for the necessary understanding of the topics This book is the one most used by residents, medical imaging faculty, and physicists On more than one occasion I have heard our university biomedical physicists ask, “What does Bushberg’s book say?” The attractive aspects of the book include its completeness, clarity, and ability to answer questions that I have This is likely a consequence of the authors having run a resident review course for almost 30 years, during which they have undoubtedly heard every question and point of confusion that a nonphysicist could possibly raise I must say that on the door to my office I keep displayed a quote from the second edition: “Every day there is an alarming increase in the number of things I know nothing about.” Unfortunately, I find this true regarding many things besides medical physics My only suggestion to the authors is that in subsequent editions they delete the word “Essentials” from the title, for that word does not justice to the staggering amount of work they have done in preparing this edition’s remarkably clear text or to the 750+ illustrations that will continue to set the standard for books in this field Fred A Mettler Jr, MD, MPH Clinical and Emeritus Professor University of New Mexico School of Medicine vii Acknowledgments During the production of this work, several individuals generously gave their time and expertise Without their help, this new edition would not have been possible The authors would like to express their gratitude for the invaluable contributions of the following individuals: Craig Abbey, PhD University of California, Santa Barbara Ramsey Badawi, PhD University of California, Davis John D Boice Jr, ScD Vanderbilt University Vanderbilt-Ingram Cancer Center Michael Buonocore, MD, PhD University of California, Davis Jiang Hsieh, PhD General Electric Medical Systems Kiran Jain, MD University of California, Davis Willi Kalender, PhD Institute of Medical Physics, Erlangen, Germany Frederick W Kremkau, PhD Wake Forest University School of Medicine Fred A Mettler Jr, MD, MPH University of New Mexico School of Medicine Stuart Mirell, PhD University of California at Los Angeles Norbert Pelc, ScD Stanford University Otto G Raabe, PhD University of California, Davis Werner Roeck, Dipl Eng University of California, Irvine Dianna Cody, PhD MD Anderson Cancer Center Linda Kroger, MS University of California, Davis Health System Michael Cronan, RDMS University of California, Davis Ramit Lamba, MD University of California, Davis John Sabol, PhD General Electric Medical Systems Brian Dahlin, MD University of California, Davis Karen Lindfors, MD University of California, Davis D.K Shelton, MD University fo California, Davis Robert Dixon, PhD Wake Forest University Mahadevappa Mahesh, PhD Johns Hopkins University Jeffrey Siewerdsen, PhD Johns Hopkins University Raymond Dougherty, MD University of California, Davis Cynthia McCollough, PhD Mayo Clinic, Rochester Michael G Stabin, PhD Vanderbilt University Ken Eldridge, RT(R)(N) John McGahan, MD University of California, Davis Steve Wilkendorf, RDMS University of California, Davis Sarah McKenney University of California, Davis Sandra Wootton-Gorges, MD University of California, Davis Michael McNitt-Gray, PhD University of California Los Angeles Kai Yang, PhD University of California, Davis William Erwin, MS UT MD Anderson Cancer Center Houston, TX Kathryn Held, PhD Massachusetts General Hospital Harvard Medical School viii Contents Preface to the Third Edition v Foreword vii Acknowledgements viii Section I: Basic Concepts 1 Introduction to Medical Imaging 1.1 The Modalities 1.2 Image Properties 15 Radiation and the Atom 18 2.1 Radiation 18 2.2 Structure of the Atom 24 Interaction of Radiation with Matter 33 3.1 Particle Interactions 33 3.2 X-ray and Gamma-Ray Interactions 38 3.3 Attenuation of x-rays and Gamma Rays 44 3.4 Absorption of Energy from X-rays and Gamma Rays 52 3.5 Imparted Energy, Equivalent Dose, and Effective Dose 55 Image Quality 60 4.1 Spatial Resolution 60 4.2 Convolution 65 4.3 Physical Mechanisms of Blurring 68 4.4 The Frequency Domain 69 4.5 Contrast Resolution 76 4.6 Noise Texture: The Noise Power Spectrum 86 4.7 Contrast 87 4.8 Contrast-to-Noise Ratio 91 4.9 Signal-to-Noise Ratio 91 4.10 Contrast-Detail Diagrams 92 4.11 Detective Quantum Efficiency 94 4.12 Receiver Operating Characteristic Curves 96 Medical Imaging Informatics 101 5.1 Analog and Digital Representation of Data 101 5.2 Digital Radiological Images 109 5.3 Digital Computers 111 5.4 Information Storage Devices 112 5.5 Display of Digital Images 116 5.6 Computer Networks 133 5.7 PACS and Teleradiology 143 5.8 Image Processing 159 5.9 Security, Including Availablility 163 Section II: Diagnostic Radiology 169 x-ray Production, X-ray Tubes, and x-ray Generators 171 6.1 Production of x-rays 171 6.2 x-ray Tubes 176 6.3 x-ray Generators 190 6.4 Power Ratings and Heat Loading and Cooling 199 6.5 Factors Affecting x-ray Emission 202 Radiography 207 7.1 Geometry of Projection Radiography 207 7.2 Screen-Film Radiography 209 ix x Contents 7.3 Computed Radiography 214 7.4 Charge-Coupled Device and Complementary Metal-Oxide Semiconductor detectors 217 7.5 Flat Panel Thin-Film-Transistor Array Detectors 220 7.6 Technique Factors in Radiography 223 7.7 Scintillators and Intensifying Screens 224 7.8 Absorption Efficiency and Conversion Efficiency 225 7.9 Other Considerations 226 7.10 Radiographic Detectors, Patient Dose, and Exposure Index 226 7.11 Dual-Energy Radiography 228 7.12 Scattered Radiation in Projection Radiographic Imaging 230 Mammography 238 8.1 x-ray Tube and Beam Filtration 240 8.2 x-ray Generator and Phototimer System 250 8.3 Compression, Scattered Radiation, and Magnification 253 8.4 Screen-Film Cassettes and Film Processing 258 8.5 Digital Mammography 263 8.6 Radiation Dosimetry 274 8.7 Regulatory Requirements 276 Fluoroscopy 282 9.1 Functionality 282 9.2 Fluoroscopic Imaging Chain Components 283 9.3 Fluoroscopic Detector Systems 284 9.4 Automatic Exposure Rate Control 292 9.5 Fluoroscopy Modes of Operation 293 9.6 Image Quality in Fluoroscopy 298 9.7 Fluoroscopy Suites 301 9.8 Radiation Dose 304 10 Computed Tomography 312 10.1 Clinical Use 312 10.2 CT System Designs 312 10.3 Modes of CT Acquisition 335 10.4 CT Reconstruction 350 10.5 Image Quality in CT 358 10.6 CT Image Artifacts 367 10.7 CT Generations 370 11 X-ray Dosimetry in Projection Imaging and Computed Tomography 375 11.1 Attenuation of X-rays in Tissue 375 11.2 Dose-Related Metrics in Radiography and Fluoroscopy 377 11.3 Monte Carlo Dose Computation 382 11.4 Equivalent Dose 383 11.5 Organ Doses from X-ray Procedures 384 11.6 Effective Dose 385 11.7 Absorbed Dose in Radiography and Fluoroscopy 386 11.8 CT Dosimetry and Organ Doses 387 11.9 Computation of Radiation Risk to the Generic Patient 394 11.10 Computation of Patient-Specific Radiation Risk Estimates 396 11.11 Diagnostic Reference Levels 397 11.12 Increasing Radiation Burden from Medical Imaging 399 11.13 Summary: Dose Estimation in Patients 400 12 Magnetic Resonance Basics: Magnetic Fields, Nuclear Magnetic Characteristics, Tissue Contrast, Image Acquisition 402 12.1 Magnetism, Magnetic Fields, and Magnets 403 12.2 The Magnetic Resonance Signal 412 12.3 Magnetization Properties of Tissues 415 12.4 Basic Acquisition Parameters 420 12.5 Basic Pulse Sequences 421 12.6 MR Signal Localization 438 12.7 “K-Space” Data Acquisition and Image Reconstruction 444 12.8 Summary 447 Isotopes, 28t Iterative reconstruction SPECT and PET, 711, 712f, 730 x-ray computed tomography, 357–358, 357f, 358f J Joint Commission See The Joint Commission Joule definition, 200–201 rating chart, x-ray tube, 376 K K shell, electron, 24–26 K-absorption edge, 244 Kerma, 52–53 Kerma-area-product (KAP), 306 Kernel, and spatial resolution, 66, 66f computed tomography, 353–354, 353f, 356f in filtered backprojection, 710–711 Keyhole filling method, magnetic resonance imaging, 456f, K-space data acquisition, magnetic resonance imaging K-space errors, magnetic resonance imaging, 478, 479f K-space filling methods, 456–457 K-space matrix, 444, 445f L Laboratory frame, 411, 412f Laboratory safety radiation protection, 885–887, 886f LAN See Local area network Larmor equation, magnetic characteristics, 409–410, 410f Laser multiformat camera, 133 Last-frame-hold, fluoroscopy, 297 Latent image center, 211 Latent stage, acute radiation syndrome, 785, 786f Lateral resolution, ultrasound, 525–526, 526f Latitude, radiography, 213 LCD See Liquid crystal display LD50/60, 787 Lead thickness, radiation shielding barriers, 859–860, 858f Leaded glasses, radiation protection, 869 Lead–zirconate–titanate (PZT), ultrasound, 514 Leakage radiation, 187, 856, 856f Leukemia, radiation induced carcinogenesis, 792t Line focus principle, x-ray tube focal spot, 182 Line spread function (LSF), 63–64, 63f, 64f, 682, 730 Linear attenuation coefficient, 45–46, 47t Linear energy transfer (LET), 36 Linear nonthreshold (LNT) model, radiation effects, 807, 807f Linear-quadratic (LQ) model, radiation effects, 765, 807, 807f Liquid crystal display (LCD), 119–121, 120f List-mode acquisition, scintillation camera, 700, 701f Local area network, 136–138 Logarithmic weighted subtraction, 230 Longitudinal magnetization, 412, 413f Look-up table, displayed contrast, image quality, 89, 90f Index 1017 Luminance, 121 film viewing, mammography, 262 digital image viewing, mammography, 269 M Magnetic dipole, 407 Magnetic field inhomogeneities, magnetic resonance imaging artifact, 497 Magnetic fields, 403–404 Magnetic forces, 922–924 Magnetic moment, defined, magnetic resonance imaging, 412 Magnetic resonance basics acquisition parameters echo time, 420–421 inversion time, 421 partial saturation, 421, 421f repetition time, 420 energy absorption and emission, 410–411, 410t, 411f frame reference, 412–413, 412f, 413f geometric orientation, 412–413, 412f, 413f K-Space data acquisition frequency domain, 444 K-space matrix, 444, 445f Nyquist frequency, 444 two-dimensional data acquisition, 445–446, 446f, 447f two-dimensional multiplanar acquisition, 446–447, 447f magnetic characteristics nuclear elements, 408, 408t nucleus, 407–408, 407f, 408t proton, 409–410, 410f magnetic fields, 403–404 magnetic susceptibility, 407 magnetism, 403 magnetization vectors, 412–413, 412f, 413f magnets air core magnets, 404, 404f bipolar gradient field, 405 electromagnet, 404 FOV, 405 gradient coils, 405, 406f internal superconducting magnet, 405, 405f magnetic field gradient, 405 quench, 405 RF coils, 405 shim coils, 405 superconducting air-core magnet, 405, 405f superconductivity, 404, 405 MR signal classical physics model, 414 electromagnetic RF wave, 414, 414f flip angles, 414–415, 415f quantum mechanics model, 413 resonance frequency, 413 RF excitation pulse, 413 MR signal localization frequency encode gradient, 441–442, 442f, 443f gradient sequencing, 444, 444f 1018 Index Magnetic resonance basics (Continued) magnetic field gradients, 438–439, 438f, 439f, 439t phase encode gradient, 443–444, 443f slice select gradient, 440–441, 440f, 442f MR system, 406, 406f Magnetic Resonance Imaging acquisition time, 449–460 ancillary equipment, 488–491 angiography, 465–469, 466f–469f artifacts, 474–486 biological effects, 496–497 blood oxygen level-dependent (BOLD), 470–471, 471f centric k-space filling, 456–457, 456f chemical shift artifacts, 480–483, 481f–483f coil quality factor, 462–463 cross-excitation, 463 data synthesis, 452–453, 452f diffusion weighted imaging, 471–473, 472f echo planar image acquisition, 454–456, 455f fast spin echo (FSE) acquisition, 453–454, 453f field uniformity, 492–493 flip angle, 414–415, 415f flow-related enhancement, 464–465, 465f functional MRI (fMRI), 470–471, 471f gradient field artifacts, 476–477, 476f gradient recalled echo acquisition, 454, 454f, 455t gradient sequencing, 444–445, 445f image acquisition, 463 image quality, 463–464 image reconstruction, 463 keyhole filling method, 456f, 457 K-space errors, 478, 479f K-space filling methods, 456–457 localization of signal, 422 machine-dependent artifacts, 474–475 magnet siting, 491–492, 492f, 493f magnetic field exposure limit, 497 noise limit, 497 magnetic field strength, 463 magnetic resonance spectroscopy, 486–488, 487f, 488t magnetization transfer contrast, 473–474, 473f motion artifacts, 479–480, 480f MR bioeffects and safety, 495–499 acoustic noise limits, 497 guidelines, 496t MR personnel, 498–499, 498f pediatric patient concerns, 498 pregnancy-related issues, 497 RF exposure, 497 safety zones, 498–499, 498f specific absorption rate, 497 static magnetic fields, 496–497 time-varying magnetic fields, 497 multislice data acquisition, 451–452, 451f parallel imaging, 457, 458f, 459 partial volume artifacts, 486 perfusion, 469–470, 470f phase encode gradient, signal localization, 455, 455f PROPELLER, 457, 458f quality control, 493–495, 494f, 494t radiofrequency coils, 489–491, 490f multi-channel encoding coils phased array coils, 489–490, 490f RF receiver coils, 489 RF transmitter coils, 489 surface coils, 489 volume coils, 489 RF artifacts, 477–478, 478f RF bandwidth, 461–462, 462f RF coil artifacts, 477, 477f RF coil quality factor, 462–463 ringing artifact, 483–484, 484f, 485f signal averages, 461 signal from flow flow-related enhancement, 464–465, 465f gradient moment nulling, 469, 469f MR angiography, 465 phase contrast angiography, 467–469, 468f, 469f time-of-flight angiography, 465–466, 466f, 467f signal-to-noise ratio, 460–461 small flip angle, gradient recalled echo, 454 spatial resolution and contrast sensitivity, 460 spin-lattice relaxation, defined, 475 spin-spin interaction spiral filling method, 456f, 457 subcomponents, 491, 491f susceptibility artifacts, 475–476, 475f three-dimensional Fourier transform imaging, signal localization, 459–460, 459f two-dimensional data acquisition, 450–451, 450f voxel volume, 461 wraparound artifact, 485–486, 485f Magnetic Resonance Imaging (MRI), 8–9, 9f Magnetic Resonance Spectroscopy (MRS), 486–488, 487f, 488t Magnetic susceptibility, 407 Magnetic tape, 114 Magnetism, 403 Magnets See Magnetic Resonance basics, magnets Magnets air core magnets, 404, 404f bipolar gradient field, 405 electromagnet, 404 FOV, 405 gradient coils, 405 gradients, coil pairs, 405, 406f internal superconducting magnet, 405, 405f magnetic field gradient, 405 quench, 405 RF coils, 405 shim coils, 405 superconducting air-core magnet, 405, 405f superconductivity, 404, 405 Magnification blurring, 209f definition, 207 edge gradient, 209 Magnification in nuclear imaging, 683–685, 690, 691f Magnification modes, fluoroscopy, 294–296 Magnification techniques, mammography, 257–258 Mammography, 5–6, 6f accreditation and certification, 277 anode, 241 automati, 251–252 average glandular dose, radiation dosimetry, 274 backup timer, 252 breast digital tomosynthesis, 272–273 Bucky factor, 256–257 cathode, 240–241 collimation, 250 compression of breast, 253–255 computer-assisted detection and diagnosis, 270 contrast, 239, 239f contrast degradation factor, 255 diagnostic procedure, 238 digital detectors and imaging, 263–268 film film and film processing, 260–261 film viewing conditions, 262–263 focal spot, 241–244 half-value layer, 247–248 magnification techniques, 257–258 mid-breast dose, radiation dosimetry, 276 molybdenum, 241 quality assurance, 281 radiation dosimetry, 274–276 reciprocity law failure, 252 regulatory requirements, 276–281 scattered radiation, antiscatter grid, 255–257 screen–film cassette and film emulsion, 258 technique chart, 252–253 tube port filtration, 244–247 x-ray generator, phototimer system, 250–253 x-ray tube design for, 188, 241, 242f Mammography Quality Standards Act (MQSA), 238 Mammography, radiation protection, 858 Management of Persons Contaminated with Radionuclides, 905 Manifest illness stage, acute radiation syndrome, 785–786, 786f, 790, 791t, 792f Mass attenuation coefficient, 47–48, 48f, 946t–954t Mass defect, 31 Mass energy absorption coefficient, 54 Mass energy transfer coefficient, 53 Mass number, 27 Matching layer, ultrasound, 516–517 Maximum intensity projection (MIP) magnetic resonance imaging, 466–467, 466f, 467f x-ray computed tomography, 161 Mean, statistics, 81–82, 81f, 667 Mean life, radiopharmaceutical dosimetry, 621 Median, statistics, 80, 80f, 667–668 Medical internal radiation dosimetry (MIRD) method, of radiopharmaceutical dosimetry, 617–625, 618f MIRD formalism, internal dosimetry, 617 radiopharmaceutical doses Memory, computer, 70–72, 71f Index 1019 Metastable state, 28 nuclear transformation, 589 Microcephaly, in utero irradiation, 826 Minification gain, output phosphor, 236 MIRD See Medical internal radiation dosimetry Mirror image artifact, ultrasound, 566f, 567 Mobile fluoroscopy, 303 Mobile radiography and fluoroscopy systems, radiation protection, 858–859 Mode, statistics, 80, 80f Modem, 142 Modulation transfer function (MTF) Fourier transform, 991–995, 992f–994f and image quality, 270–271, 270f, 271f, 272f limiting resolution, 72, 72f Nyquist frequency, 73–74, 73f, 74f practical measurement, 72 presampled MTF, 74–75 RECT input function, 75–76, 75f resolution test phantoms, 76, 76f SINC function, 75, 75f Molybdenum breakthrough See Mo-99/Tc-99m radionuclide generator Molybdenum-99, decay schemes, 580, 581t, 591f Momentum, 916 Monitor pixel formats, 125–126 Monte Carlo dose computation, 382–383 Mo-99/Tc-99m radionuclide generator, 603–604 quality control, 607–608 molybdenum breakthrough, 607 MR See Magnetic Resonance basics, Magnetic Resonance Imaging MR signal localization frequency encode gradient, 441–442, 442f, 443f Gradient Sequencing, 444, 444f magnetic environment, 438, 438f magnetic field gradients, 438–439, 438f, 439f, 439t phase encode gradient, 443–444, 443f slice select gradient, 440–441, 440f, 442f MTF See Modulation transfer function Multichannel analyzers (MCAs) system, pulse height spectroscopy, 653–654, 654f Multi-channel encoding coils, 490 Multienergy spatial registration, 685, 685f Multi-path reflection artifact, ultrasound, 566f, 567 Multiple detector arrays, x-ray computed tomography, 313–314, 317–318, 329–333, 314f, 317f, 318f, 329f, 330f, 331f, 332f Multiple exposure, rating chart, 142 Multiplication factor, nuclear reactor, 600 Multiply damaged sites (MDS), DNA, 754 Multirow detector CT scanners (MDCTs), radiation protection, 858, 865–867 Multislice data acquisition, magnetic resonance imaging, 431 Multitarget model, cell survival curves, 764–765, 764f, 766f Mutual induction, 925–926, 926f 1020 Index N Narrow-beam geometry, 48, 48f National Electrical Manufactures Association (NEMA), specifications, scintillation camera, 694 Nationwide Evaluation of X-Ray Trends (NEXT), 879 Near field, ultrasound beam, 520–521, 521f Negative predictive value (NPV), 99 Negatrons See beta minus particle and beta minus decay Neurovascular radiation syndrome, 790 Newton’s laws, 915 Noise, and image quality, 524f, 562 Nonionizing radiation, 22 NRC See Nuclear Regulatory Commission Nuclear binding energy, 31 Nuclear chain reaction, 599, 600f Nuclear fission, 31, 32f nuclear reactor produced radionuclide, 598–599 Nuclear forces, atom, 27–28 Nuclear fusion, 32 Nuclear magnetic moment, 407 Nuclear magnetic moment, 407 Nuclear magnetic resonance (NMR), 402 Nuclear medicine, 880–892 distance, exposure, 880–882, 881t exposure time, 880, 880t patient protection, 887–891, 889t radioactive material spills, 887 radioactive waste disposal, 891–892 radionuclide generator, 607t shielding, 882–887 Nuclear medicine planar images, 11, 12f Nuclear reactor, 598–603 Nuclear reactor-produced radionuclide chain reaction containment structure, 602 fast neutron, 599 meltdown, 600 multiplication factor, 600 uranium 235, 598, 599f fission, 598–599 neutron activation, 602–603, 603t Nuclear Regulatory Commission (NRC), 629, 896t Nuclear stability, 28, 30, 30t, 29f Nuclear terrorism, radiation protection, 903–904, 904f Nuclear transformation, 582–593 alpha decay, 583–584, 583f beta-minus decay negatron, 584–585, 584f, 585f beta-plus decay positron emission, 585–587, 586f decay schemes, 589–593, 589f–592f, 593t fluorine-18, 581t, 592f molybdenum-99, 580, 581t, 591f phosphorus-32, 581t, 589, 590f radon-220, 589, 590f technetium-99m, 580, 581t, 592f electron capture decay, 587–588, 588f isomeric transition, 588–589 metastable state, 589 metastable states, 588 pure beta emitter, 590 radioactive decay, 582 radioactivity, 579 Nucleon, 27 Nuclide classification, 28, 28t Number system binary form, 101–102, 102t conversion, decimal form, binary form, 102, 103t decimal form, 101 Nyquist frequency, 73–74, 73f, 74f, MRI, 444 Doppler ultrasound, 546–547, 547f O Occupancy factor (T), radiation shielding, 861 Off-focus radiation, anode, 185, 186f, 241 Ohm’s law, 921 Optical coupling, fluoroscopy, 287 Optical density, light transmission relationship, 259 Optically stimulated luminescent (OSL), 845–846, 845f, 846f Optics, 285–286 Orbital binding energy, 24–25 Organ conversion factors, 383t Organ dose, 384–385, 384t, 955, 958t Organ response to radiation See Tissue reactions Organogenesis, radiation effects on the fetus, 825 OSL See Optically stimulated luminescent (OSL) Output phosphor, fluoroscopy, 286–287, 286f P PACS See Picture archiving and communication system Packet, 134 Pair production, 44, 45f Pancake probe, radiation protection, 851 Par speed system, 258 Parallel beam geometry, x-ray computed tomography, 316 Parallel-hole collimator, 678, 678f Paralyzable model, of pulse mode, for radiation detection, 635, 635f Paramagnetic materials, 928 Parent nuclide, 30 Partial saturation, 421 Partial volume effect, 745 x-ray computed tomography, 368–369, 369f Particulate radiation, 22–24, 23t Path length, particle, 35 PEG See Phase encode gradient Period, 21 Peripheral angiography suites, 302–303 Personnel dosimetry direct ion storage dosimeter, 846, 847f dosimeter placement, 847–848 dosimeter use, 847 film badge, 843–844, 844f pocket dosimeter, 848–849, 849f, 850t problems with, 849–850 protective aprons, 848 thermoluminescent dosimeter (TLD), 845–846, 845f, 846f PET See Positron emission tomography PET/CT imaging artifacts attenuation correction artifacts, 740, 740f spatial misregistration, 739, 739f truncation artifacts, 741 attenuation correction, 737–738, 738t PET/MRI system, 741–742 Phase encode gradient (PEG), magnetic resonance imaging, 443–444, 443f signal localization, 455, 455f Phased array coils, magnetic resonance imaging 489–490 Phased array transducer, ultrasound, 518–519, 519f, 559, 559f Phosphorus-32, decay schemes, 581t, 589, 590f Photodiode computed tomography, 329, 330f, 645 scintillation detector, 647 TFT array, 226, 265–266, 266f Photoelectric absorption See Photoelectric effect Photoelectric effect, 20 Photoelectron, 41–44, 43f, 44f Photomultiplier tube (PMT) scintillation camera, 676, 676f scintillation detector, 645, 647, 647f Photon, 18 Photopeak, 656, 656f Photopeak efficiency, scintillation camera, 686 Photostimulable phosphor, 648 Photostimulable storage phosphor (PSP), 214, 871 Phototimer system exposure timing, 198 mammography, 250–253 Physical constants, 938t–939t Picture archiving and communications systems (PACS), 143–144, 144t, 209 ambient viewing conditions, 156 challenges, 156–157 DICOM, 147–148 digital images, 124t, 145–146, 146f display workstations, 154–156 hospital information system, 148–149 IHE, 149 image display, 154 image storage, 150–154, 152t, 153f image transfer, 146–147 quality control, 157–159 radiology information system, 148–149 teleradiology, 145 Piezoelectric crystal, ultrasound, 513–515, 514f Pincushion image distortion, in fluoroscopy, 298–299 Pinhole camera, focal spot size, 183, 185f Pinhole collimator, 678f, 679 Pocket dosimeter, 848–849, 849f, 850t Point spread function (PSF), 61–63, 61f, 62f Poisson distribution, 84–85, 84f, 86t Polyenergetic x-ray beam, 51 Portable ionization chamber, 851–852 radiation protection, 642f Positive predictive value (PPV), 99 Index 1021 Positron emission tomography (PET), 12–14, 14f, 597, 597f annihilation coincidence detection, 721–723, 723f attenuation and attenuation correction, 732–734, 733f, 734f clinical importance, 722interaction timing and coincidence detection, 726 photomultiplier tubes, 723–725, 724f, 725t, 726f quality control, 735 quantitative imaging, 744–746 radiation protection, 842 radiopharmaceuticals, 742–743 random coincidence, 723, 723f scatter coincidence, 723, 723f, 727 SPECT, compared, 743–744, 744f time of flight, 730 transverse image reconstruction, 730 true coincidence, 723, 723f true vs random coincidences, 726–727 two-and three dimensional data acquisition, 727–730, 728f, 729f Positrons, 22, 722–723 Potential energy, 916 Power Doppler, 553–554, 554f Prefixes, units, 938t–939t Preimplantation, 824 Pressure, ultrasound, 501f, 504–506, 506t Primary barrier, radiation protection, 861–862 Primary x-rays, 375 Primordial radionuclides, 838 Probability density functions, 588 Procedural pause, fluoroscopy, 308 Prodromal stage, acute radiation syndrome, 785, 786f, 787t Projection imaging, Projection radiography, 207–209, 207f–209f absorption efficiency, 225–226, 225f conversion efficiency, 225–226, 225f densitometer, 261 latitude, 213–214 overall efficiency, 244 Promotion, cancer development stages, 794 PROPELLER, magnetic resonance imaging, 457, 458f Proportional counter, gas-filled radiation detector, 641 Proportional region, gas-filled radiation detector, 639 Protective aprons, 848 Protocol, computer network, 134 Proton, magnetic resonance imaging, 409–410, 410f Pulse echo operation, ultrasound, 10, 10f Pulse height analyzers (PHAs), 651 multichannel analyzer, 653–654, 654f single channel analyzer, 652–653, 652f, 653f Pulse height spectroscopy, 651–659 cesium-137, spectrum of, 655–657, 656f iodine-125, spectrum of, 657–658, 658f technetium-99m, spectrum of, 657, 657f Pulse mode, radiation detection, 634–635, 635f non-paralyzable mode, 635, 635f paralyzable model, 635, 635f Pulse repetition frequency (PRF), ultrasound, 530, 530f Pulse repetition period (PRP), ultrasound, 530, 530f 1022 Index Pulse sequences, Magnetic resonance imaging contrast-weighted images, 421 gradient echo coherent GE, 432–434, 433f, 434t FID signals, 431 flip angle, 431, 342f GE acquisition, 436 GE sequences, 437, 437f incoherent GE, 434–436, 435f magnetic field gradient, 430 Mxy signal, 431 rotating frame, 428f, 431f short TR, 432, 433f spoiled GE, 434–436, 435f steady-state free precession (SSFP), 436, 436f, 437f inversion recovery FLAIR, 429–430, 430f RF sequence, 428, 428f steady-state equilibrium, 427 STIR, 428–429, 428f, 429f spin echo contrast weighting, 422–423 90-degree pulse, 422, 422f 180-degree RF pulse, 422, 423f proton density weighting, 424–425, 425f, 427t SE parameters, 424, 427f, 427t T1 weighting, 423, 424f T2 weighting, 425–426, 426f Pulsed fluoroscopy, 293–294, 294f radiation protection, 872 Q Quality control dose calibrator, 665–666, 666f mammography, 260–262 PET, 735 scintillation, 695–697, 696f, 697f SPECT, 13, 717–721 thyroid probe, 663 well counter, 663 Quality factor, ultrasound, 516 Quanta, 18 Quantization, data conversion, 108 Quantum detection efficiency (QDE), 225, 291f radiation detection, 637 Quantum levels, electron, 24 Quantum limited detector., 219 Quantum mechanics model, 413 Quantum noise, 80 Quantum number, electron shell, 24 R Rad definition, 54 roentgen to rad conversion factor, 274 RADAR formalism, internal dosimetry, 618–620, 619f Radiation absorption, 18 electromagnetic radiation, 18–22 electromagnetic spectrum, 19f electromagnetic wave characteristics, 21, 21f electron interaction bremsstrahlung radiation, 37 elastic, 36 inelastic, 37 electron transitions, 26–27 frequency, 21 Gamma ray, 20, 30 interaction with matter, 18 attenuation, electromagnetic radiation, 38–44 linear attenuation coefficient, 45–47, 46f mass attenuation coefficient, 47–48, 48f particle interactions, 33–38 internal conversion electrons, 30 ionization, defined, 633 ionizing radiation, 22 leakage, 187 mass-energy equivalence, 23–24 neutron interactions, 38, 38f particle characteristics, 21–22 photon, 21 quanta, 18 particle interaction annihilation, 726 Bragg peak, 35 delta rays, 33 excitation, 33–37, 34f ionization, 34–37, 34f, 35f linear energy transfer, 36 radiative loss, 33–37, 37f secondary ionization, 33 specific ionization, 34–35, 35f particulate radiation, 22–24, 23t photon, 18, 22 quanta, 18 quantities and units fluence, 52 flux, 52 gray, 53 kerma, 52–53 rad, 54 rem, 57 roentgen, 55 sievert, 56 radio frequency, 18 scattering, 18 types of, 18 uncharged particle interaction, 36 wavelength, 21 wave-particle duality, 18, 20, 20f weighting factor, 56 x-ray, 18, 26 Radiation biology acute radiation syndrome, 785–791 biological effects classification of, 752 determinants of, 751–752 deterministic, 752 stochastic, 752 cellular radiobiology adaptive response, 770–771 bystander effect, 771–772 cell survival curves, 764–765, 764f, 766f cellular radiosensitivity, 766–770, 770t genomic instability, 772 deterministic effects See Tissue reactions hereditary effects of radiation exposure, 821–823 organ response to high dose See Tissue reactions radiosensitivity, 774, 774f, 775t regeneration/repair, 773, 773f reproductive organs, 777, 781–782 skin, 774–777, 778t, 779f, 780f, 781t threshold doses, adults, 783t, 784t radiation-induced carcinogenesis, 788–818 age and gender risk estimates, 811–814, 811t–812t, 813f, 814f age as risk factor, 797–798 BEIR VII report, 806 breast cancer, 819–821, 820t cancer developmental stages, 794 dose rate and fractionation, 797 dose-response models, 804–809, 807f, 808f environmental risk factors, 794–795 epidemiologic investigations, 799–802, 800f–801f, 801t, 803t, 804t genetic susceptibility, 798–799 incidence rate, 791–792 leukemia, 816, 818f lifetime risk estimate, cancer incidence and mortality, 792, 793t low-dose, low-LET radiation, 802, 805–806 molecular biology and cancer, 793–794 multiplicative and additive risk models, 809–811, 810f, 810t population radiation risk estimates, 814–816, 815f, 815t, 817f radiation quality, 796–797, 797f risk expressions, 795–796 thyroid cancer, 817–819 radiation-induced DNA damage and response chromosomal aberrations, 762–763, 763f DNA damage spectrum, 757–760, 759f, 760f DNA repair, 761–760, 761f tissue/radiation interaction, 752–757, 753f, 756f, 757f in utero, radiation effects gestation, 824–831 radionuclides, 828, 830–831 Radiation detection anions, 633 cation, 633 counters, 634 current mode, 634–635, 635f dead-time, 634 detector types, 633–637 dosimeter, 634 efficiency, detection, 636–637, 637f energy-compensated detectors, 642 exposure rate, 639 gas-filled radiation detector, 637–643 Geiger-Mueller counter, 641–643, 642f ionization chamber, 639–641, 640f proportional counter, 641 Geiger-Mueller region (GM region), 639 Index 1023 ionization chamber region, 639 proportional region, 639 pulse height spectrum, 635–636, 636f pulse mode, 634–635 non-paralyzable model, 635, 635f paralyzable model, 635, 635f recombination region, 639 reverse bias, 647 scintillation detector See Scintillation detector semiconductor detector, defined, 651 spectrometers, defined, 634 spectroscopy, defined, 635, 636f systematic error, 667 thermoluminescent dosimeter, 648 TLD, 648 Radiation dose annual cosmic radiation doses, 998, 1003f vs effective dose, 998, 1003f emission of radiation, 998, 1000f estimated effective doses vs.standard myocardial perfusion, 998, 1001f ICRP tissue weighting factors, 998, 999t imparted energy, 55–56 life expectancy, 998, 1002t natural and artificially produced sources, 998, 1003t organ equivalent doses, 998, 1000f public and occupational radiation exposure, 998, 1002t Radiation Dose Structured Report (RDSR), 875 Radiation protection accident, 902–903 acute radiation syndrome, 906–907 advisory bodies International Commission on Radiological Protection, 893 National Council on Radiation Protection and Measurement, 893 bone mineral densitometry x-ray system, 859 by-product material, 892 capita effective dose, 840f collective effective dose, 840, 840t committed dose equivalent, 894 computed tomography, patient protection, 874–877, 875t, 876t consumer products and activity, 841 contamination control and survey, 883, 885 controlled and uncontrolled areas, 855 decay chain, 838 dental and veterinary x-ray facilities, 859 design goals, 855, 856 diagnostic and interventional X-ray imaging patient protection, 869–879 personnel protection, 867–869, 868f, 870f dose limit, 894 dose optimization, 876–877 effective dose equivalent, 894 equipment, 850–852 Geiger-Mueller survey instruments, 850–851 portable ionization chamber, 851–852 error prevention, 897–899 exposure control See Exposure control 1024 Index Radiation protection (Continued) exposure rate constant, 881, 883t external radioactive contamination, 904–905 fluoroscopic imaging systems, 857 fluoroscopy, 872–874 gonadal shielding, 871 imaging of pregnant patients, 901–902 intake and derived air concentration, 894–895 internal radioactive contamination, 905, 906t leaded glasses, 869 leakage radiation, 856, 856f mammography, 858 management, 899–900 management of persons contaminated with radionuclides, 905 MDCTs, 858 medical events, 887 mobile radiation barrier, 869 mobile radiography and fluoroscopy systems, 858–859 natural radiation, 839, 841 nuclear medicine, 880–892 distance, exposure, 880–882, 881t exposure time, 880, 880t patient protection, 887–891, 889t radioactive material spills, 887 radioactive waste disposal, 891–892 shielding, 882–887 occupational exposure, 841–842 optically stimulated luminescent dosimeters, 845–846, 845f, 846f pancake probe, 851 patient protection, 869 tube voltage and beam filtration, 870 x-ray image receptor, 871–872 personnel dosimetry direct ion storage dosimeter, 846, 847f dosimeter placement, 847–848 dosimeter use, 847 film badge, 843–844, 844f pocket dosimeter, 848–849, 849f, 850t problems with, 849–850 protective aprons, 848 thermoluminescent dosimeter (TLD), 845–846, 845f, 846f PET, 842 PET/CT and SPECT/CT shielding, 867 photostimulable storage phosphor (PSP), 871 primordial radionuclides, 838 protective gloves, 869 radioactive waste disposal, 891–892 radiographic room, 860f, 862, 863f radiological and nuclear terrorism, 903–904, 904f radionuclide therapy, 888–891 radon-222, 838, 839 RDSR, 875 regulatory agencies, 892–893 safety culture, 898 scattered radiation, 856, 856f secondary barrier, 862 sentinel event, 898 shielding barrier calculation CT scanner, 865–867, 865f, 866f radiographic room, 862–864, 863f, survey, 864–865 shielding terminology, 860–862, 860f, 861t workload distribution, 860–861 special nuclear material, 892 Radiation Risks of Diagnostic Imaging, 898 Radiation weighing factor, 56 Radiation-induced arteriole fibrosis, 774f Radio nuclide production, 594–608 Radioactive decay, 30, 579, 581t, 582 activity, 579 decay constant, 579–580 fundamental decay equation, 582 physical half-life, 580–581, 581t Radioactivity, 28, 30 Radiofrequency (RF) coils, 405 Radiography, 4–5, 4f, 5f absorption efficiency, 225–226 CCD chip amount of light, 218 dexel, 217 slot-scan X-ray systems, 219 X-ray quantum limited detector, 219 CMOS, 219–220 computed BaFBr, 214 F-center, 215, 216 imaging plates, 214 laser light stimulation, 214 PSP, 214 readout mechanics, 215f storage phosphor, 214 conversion efficiency, 225–226 detectors histogram values, 227 speed, 213 dose-related metrics, 377–382 dual-energy attenuation characteristics, 229 chest radiography, 229 Compton scattering component, 229 logarithmic weighted subtraction, 230 geometry of projection beam divergence, 207 detector, 207 SID, 208 intensifying screens, 210, 224–225 proprietary exposure index (EI), 228 scatter reduction, 235–236 scattered radiation anti-scatter grid See Anti-scatter Grid scatter-to-primary ratio, 231 X-ray, 230 scintillators, 224–225 screen-film See Screen-film radiography skin dose, 380 technique factors, 223–224 Radiology information system (RIS), 148–149 Radionuclide generator Mo-99/Tc-99m radionuclide generator, 603–604 nuclear medicine, 607t quality control, 607–608, 666 secular equilibrium, 606, 608f Sr-82/Rb-82 generator, 666–667 transient equilibrium, 604, 606, 606t Radionuclide production, 594–608 containment structure, 601 control rods, 600 cumulated activity, 620 cyclotron-produced radionuclide, 594–598, 595f, 597f effective half-life, 620 fission fragments, 598 fuel rods, 600 generator See Radionuclide generator mean life, 621 meltdown, 600 molybdenum breakthrough, 607 multiplication factor, 600 neutron activation, 601 nuclear reactor-produced radionuclide, nuclear fission 606–611,607f reactor, 600, 601f S factor, 618 supercritical, 600 thermalize, 599 time-integrated activity, 618 U.S Pharmacopeia (USP), 608 Radionuclide therapy, 1005–1007 radiation protection, 888–891 Radiopharmaceuticals, 608–616 absorbed dose, 976t–977t administration methods, 956t–967t adult dose, 968t–971t authorized user, 629 breast dose, 981t breast-feeding, 984–985 byproduct material, 629 clinical utility, 956t–967t dose from, 743 effective dose, 972t–973t newborn and infant, 978t ideal diagnostic high target/nontarget activity, 609, 613 low radiation dose, 609 safety, 613 internal dosimetry, 617 localization, 956t–967t localization mechanisms, 613–616 medical events, 630–631 medical imaging, 608–609 NDA, 628 physical characteristics of, 610t–612t quality control, 616 safety, 613 U.S Food and Drug Administration, regulation, 628 written directive, 629–631 Radon-220 decay schemes, 589, 590f Radon-222, 838, 839 Index 1025 Random error, counting statistics, 667 Random number generator, 382 Range, particle, 35 Rayleigh scattering, 38–39, 39f RDSR See Radiation Dose Structured Report (RDSR) Readout gradient, 441 Receive focus, ultrasound beam, 522, 522f Receiver operating characteristic (ROC) curves, and image quality, 96–99, 96f, 97f, 99f Reciprocity law failure, mammography, 252 Recovery stage, acute radiation syndrome, 785, 786f Rectifier circuit, x-ray, 192 Reference axis, x-ray beam, mammography, 243 Reference levels, 878–879 Reflection, ultrasound, 508–509, 508f, 509t Refraction, ultrasound, 508f, 509–510 Refraction artifacts, ultrasound, 563, 564f Relative biological effectiveness (RBE), 756 Relative risk (RR), radiation biology, 795 Remote fluoroscopy rooms, 301–302 Resonance transducers, ultrasound, 515, 515f Reverberation, ultrasound, 563–564, 565f Reverse bias, photodiodes, 647, 650 RF coil safety, magnetic resonance imaging, 491 RF receiver coil, 489 RF transmitter coils, 489 Road mapping, fluoroscopy, 297 ROC See Receiver operating characteristic Roentgen definition, in exposure rate constants, 882–883 to rad conversion factor, 274 Roentgenography, 4–5, 4f, 5f Rotating anode, 180 Rotating frame, magnetic resonance imaging, 411 Rotor/stator, x-ray tubes, 176, 180–182, 180f, 181f Routers, 140 S S distortion, fluoroscopy, 290 Sampling analog-to-digital converters, 108 image quality and, 62, 64, 64f Sampling pitch computed tomography, 338 mammography, 265 Scatter (contrast) degradation factor mammography, 255 Radiography, 235 Scattered radiation antiscatter grid mammography, 255–257 in nuclear imaging, 681 in projection radiography system, 207–209, 207f–209f radiation protection, 856, 856f scatter coincidences, 727 Scattered x-rays, 375 Scintillation camera collimator, 677–679, 678f efficiency, 688–690, 689f, 690t resolution, 688–690, 689f, 690t 1026 Index Scintillation camera (Continued) design, 686–694 collimator resolution, and collimator efficiency, 688–690, 689f, 690t detector, 676–677, 676f electronics, 676–677, 676f intrinsic spatial resolution, and intrinsic efficiency, 686–688, 687t spatial linearity, and uniformity, 691–694, 692f, 693f system spatial resolution, and efficiency, 690–691, 691f energy resolution, 686 image formation principles, 680–681, 680f intrinsic efficiency, 686–687, 686–688, 687t intrinsic resolution, 683 intrinsic spatial resolution, and intrinsic efficiency, 686–688, 687t multienergy spatial registration, 685, 685f multiple window spatial registration, 685 National Electrical Manufactures Association (NEMA), specifications, 694 operation/quality control, 695–697, 696f, 697f performance, 682–686 measures, 682–686, 683f–685f photopeak efficiency, 686 radiation, 18, 36 region of interest (ROI), 701 scintillation camera, 674–704 spatial linearity, 691–694, 692f, 693f spatial resolution, 682 system efficiency, 685 uniformity, 691–694, 692f, 693f Scatter-to-primary ratio (SPR), 231 Scintillation detector, 643–648 afterglow, defined, 643 excited electron, 647–648 photostimulable phosphor, 648 thermoluminescent dosimeters, 647 inorganic crystalline scintillator, 644–645, 646t luminescence, 643 photodiode, 647 photomultiplier tube, 645, 647, 647f photostimulable phosphors, 648 Scintillators, 224–225 Screen-film combination, screen-film system, 258 Screen-film radiography characteristic curve H and D, 212 film contrast, 213 intensity of light, 213 latitude, 214 double-sided screen-film, 210f film processing, 211–212, 212–213 grain shape, 211 indirect detection process, 211f latent image center, 211 Screen-film systems projection radiography, 209 Screening mammography, 238 Screens composition and construction, 210 intensifying, 224–225 Secondary barrier, radiation protection, 862 Secondary ionization, 33 Secondary quantum sink, 219 Sector scanning, ultrasound imaging, 10 Secular equilibrium, 606, 608f SEG See Slice encode gradient Segmentation, three-dimensional image display, x-ray computed tomography, 161 Selectivity, grids, 235 Self-induction, 924–925 Self-magnetism, 407 Semiconductor detector, radiation detection, 648–651, 649f, 650f Sensitivity speck, film processing, 211 Sensitometer, 261, 261f Sentinel event, radiation protection, 898 Septa, scintillation camera collimator, 677 Server, 133 Shadowing artifact, ultrasound, 563, 564f Shielding barrier calculation, 866–867, 866f calculation, 862–864, 863f CT scanner, 864–866, 865f, 866f diagnostic radiology, 854 exposure control, 854 installation, 864 nuclear medicine, 882–887 PET/CT and SPECT/CT, 867 Shift invariant, point spread function, 62 Shim coils, magnetic resonance imaging, 405 SID See Source-to-Imager Distance Side lobe artifact, ultrasound, 523f, 524f, 565f, 566–567 Side lobe, ultrasound beam, 523, 523f, 524f Sievert, 56 Signal averages, magnetic resonance imaging, 461 Signal-to-noise ratio (SNR), 91–92, 92f Similar triangles, basic geometric principles, 207 Simple backprojection, x-ray computed tomography, 351–352 Simple kinetic model, internal dosimetry, 620, 621f Single channel analyzers (SCAs), pulse height spectroscopy, 652–653, 652f, 653f Single exposure, rating chart, 200 Single film emulsion, single screen, mammography, 258 Single phase x-ray generator, 195, 197, 200 Single photon emission computed tomography (SPECT), 12, 13f attenuation correction in, 712–713, 712f axis of rotation (AOR), 717–718, 718f collimator, 714, 714f conventional planar imaging, compared, 716 coronal and sagittal image generation, 713 head tilt camera, 719–720, 719f image acquisition, 706–707, 709, 709f multienergy spatial registration, 717 multihead cameras, 714–715 oblique image generation, 713–714 phantoms, 720, 720f, 721t positron emission tomography, compared, 743–744, 744t principle, 706, 707f, 708f quality control, 717 quantitative imaging, 744–746 spatial resolution, 715, 716f transverse image reconstruction, 709–711, 710f, 711f, 712f uniformity, 718–719, 718f X and Y magnification factors, 717 Sinogram, tomographic reconstruction, 355f, 721 Skin dose, 380–382 Skin, response to radiation, 774–777, 778t, 779f, 780f, 781t Slice encode gradient (SEG), magnetic resonance imaging, signal localization, 459 Slice sensitivity profile, x-ray computed tomography, 360, 361f, 362f Slice thickness contrast resolution, x-ray computed tomography, 366 magnetic resonance imaging, 460–461 single detector array scanners, computed tomography, 333–334 spatial resolution, x-ray computed tomography, 366 ultrasound, 567–568, 568f Slip-ring technology, helical scanner, x-ray computed tomography, 372 Slit camera, focal spot x-ray tube, 183 Smoothing, spatial filtering, computer image processing See Spatial filtering SNR See Signal-to-noise ratio SOD See Source-to-object distance (SOD) Sodium iodide scintillator, 676 Sodium iodide thyroid probe/well counter, 660–663, 660f, 662f Sodium iodide well counter, 661–662, 662f Software applications programs, 112, 141, 937 computer languages high-level languages, 937 machine language, 937 operating system, 937 Solid-state detector, x-ray computed tomography, 329 Sound See Ultrasound Source to imager distance (SID), 208 Source-to-object distance (SOD), 871 Source-to-skin distance (SSD), 377–378, 379f Space charge effect cathode, 178f mammography, 250 Space charge limited, cathode, x-ray tubes, 178f Spatial filtering, nuclear imaging, 701 Spatial resolution, 298–299, 299f convolution, 994 Fourier transform, 991, 993f, 995 image quality, 60–65 line spread function, 730 ultrasound beam, 524–527 x-ray computed tomography Spatial resolution, line spread function, 689f x-ray computed tomography, 675 Index 1027 Specific ionization, 34–35, 35f SPECT See Single photon emission computed tomography Spectroscopy defined, 635–636, 636f radiation detection, 635–636, 636f SPECT/X-ray CT system myocardial perfusion imaging, 741 Speed artifact, ultrasound, 565f, 566 Speed, of sound, 501f, 502–504, 503t, 505f Spin echo, magnetic resonance imaging, 422 Spin-lattice relaxation, magnetic resonance imaging, 418 Spin-spin interaction, magnetic resonance imaging, 417f Spiral filling method, magnetic resonance imaging, 456f, 457 Spoiled gradient echo technique, magnetic resonance imaging, 434–436 Spurs, 753 Standard deviation, image quality, 363–364 Standardized uptake value (SUV), PET imaging, 745 Star pattern, focal spot size, 183, 184, 186f Static, frame mode acquisition, image acquisition, 699–700, 699f Stationary x-ray tube anode, 180 Stationary invariant, point spread function, 62 Stereotactic breast biopsy, 270–271 Stochastic effect, radiation-induced cancer, 752 Storage of images data compression, 152–154 image management, 151–152 schemes, 150–151 Storage phosphors, 214 Structure, atom See Atom structure Structure noise, 78f, 79 Subject contrast, and image quality, 87–88, 88f Sum peak, radiation spectrum, nuclear imaging, 658 Superconductivity magnets, magnetic resonance imaging, 404, 405 Surface coils, magnetic resonance imaging, 489 Surface rendering, three-dimension image display, x-ray computed tomography, 161 Susceptibility artifacts, magnetic resonance imaging, 407 System efficiency, scintillation camera, 685 Systematic error, counting statistics, 667 Systeme International (SI), 914 T T1 weighting, magnetic resonance imaging, 423, 424f T2 weighting, magnetic resonance imaging, 425–426, 426f Target exposure index, 228 TCP/IP See Internet Protocol Suite TDI See Time delay and integration Technetium-99m decay schemes, 580, 581t, 592f spectrum of, 657, 657f Technique chart, mammography, 252–253 Teleradiology quality control, 157–159 Temporal resolution, 300–301 1028 Index Teratogenic effects, in utero irradiation, 825–827 TFT See Thin-film transistor The Joint Commission, 897–899 Thermionic emission cathode, 177, 178f Thermoluminescent dosimeter (TLD), 648 radiation detection, 648 radiation protection, 845–846, 845f, 846f Thin-film-transistor (TFT) displays, 220 flat panel radiographic detector, 220–222 Three-dimensional Fourier transform imaging, signal localization, 459–460, 459f Three-phase x-ray generator, 195 Threshold, radiation exposure, 807, 807f Thyroid cancer, radiation induced carcinogenesis, 817–819 Thyroid probe-well counter, sodium iodide, 660–663, 660f, 662f Thyroid shields, radiation protection, 869 Thyroid uptake measurements, 661 Time delay and integration, 219 Time of echo (TE), magnetic resonance imaging, 420–421 Time of inversion (TI), magnetic resonance imaging, 421 Time of repetition (TR), magnetic resonance imaging, 420 Time-activity curve (TAC), scintillation camera, 701 Tissue weighting factors, 384t Tissue reactions, radiation 772–784, 783–784t ocular effects, 782–783 radiosensitivity, 774, 774f, 775t regeneration/repair, 773, 773f reproductive organs, 777, 781–782 skin, 774–777, 778t, 779f, 780f, 781t threshold doses, adults, 783–784t Tissues magnetization properties free induction decay amorphous structure, 416 antenna coil, 415 inhomogeneities, 416 magnetic field domains, 416 phase coherence, 416 sinusoidal electronic signal, 415, 416f T2 relaxation time, 416, 417f longitudinal magnetization equilibrium, 417 spin-lattice relaxation, 417, 417f, 418f, 419f T1 relaxation time, 418 tumbling frequencies, 418, 419f T1 and T2 comparison, 419–420, 419f, 420t TLD See Thermoluminescent dosimeter (TLD) Tomographic emission images, 12, 13 Tomographic reconstruction See Image reconstruction Transducer arrays, ultrasound, 513–519, 513f, 514f, 515f, 516f, 527 Transducer, ultrasound, 513–519, 513f, 514f, 515f, 516f Transformers, x-ray, 191–194, 192f Transient equilibrium, 604, 606, 606t Transmission Control Protocol/Internet Protocol See Internet Protocol Suite Transmission imaging, Transmit focus, ultrasound beam, 22–23, 23f Transmit/receive switch, ultrasound system, 529 Transmittance, optical density, film, 259 Transverse magnetization, 412 True-positive fraction (TPF), 97 Tube output, mammography, 248–250 Tube port and filtration mammography, 244–247 Tube, x-ray See X-ray, tube Tumor suppressor genes, 793 Tungsten atom, de-excitation of, 27f Two dimensional data acquisition, magnetic resonance imaging, 450–451, 450f “Two-pulse” waveform, x-ray generator circuit designs, 197 U Ultrasound, 500–576 See also Doppler ultrasound absorption, 507 acoustic impedance, 507, 507t acoustic power, pulsed ultrasound intensity, 572–574, 573f, 573t ambiguity artifact, 567 A-mode transducer, 533f, 534–535 analog to digital conversion, 531, 532f array transducer, 521–524, 522f artifacts, 560–568 attenuation, 511–513, 511t, 512f axial resolution, and image quality, 524–525, 525f beam former, 529 beam steering, 532, 532f biological mechanism, effect, 574–575, 576f B-mode, transducer, 536, 537f characteristics 501–506 contrast sensitivity, noise, and image quality, 562 damping block, 515–516, 516f decibel, 506, 506t demodulation and envelope detection, 534 Doppler performance measurements, 571 dynamic focusing, 532, 532f dynamic range, 534 electronic scanning and real-time display, 537–539, 538f, 539f elevational resolution, and image quality, 524f, 527, 527f enhancement artifact, 563, 564f frequency, 501f, 502–504, 503t, 505f grating lobe artifact, 523f, 524f, 565f, 566–567 harmonic imaging, 556–559, 557f, 558f image data acquisition, 527–536 image quality, 560–568 intensity, 501f, 504–506, 506t interaction with matter, 506–513 lateral resolution, and image quality, 525–526, 526f logarithmic amplification, 534 longitudinal wave, 502 matching layer, 516–517 measurements area, distance, volume, 554–555, 555f mechanical energy, propagation, 501–502, 501f mechanical scanning and real-time display, 537 mirror image artifact, 566f, 567 M-mode, transducer, 535, 535f multipath reflection artifact, 566f, 567 phased array, 519 piezoelectric crystal, 513–515, 514f preamplification, 531, 532f pressure, 501f, 504–506, 506t pulse echo operation, 529–531, 530f, 531t pulse echo technique, 507, 507t pulser, 529 quality assurance, 567f, 568–571, 568f, 571t receiver, 532–534, 533f rectification, 534 reflection, 508–509, 508f, 509t refraction, 508f, 509–510 resonance transducers, 515, 515f reverberation, 563–564, 565f scan converter, 536 scattering, 510–511, 510f shadowing artifact, 563, 564f side lobe artifact, 523f, 524f, 565f, 566–567 signal summation, 532, 532f slice thickness, 567–568, 568f sound, characteristics of See Sound, characteristics of spatial compounding, 539 spatial resolution, 527f, 535f, 561–562 special purpose transducer assemblies, 559 specular reflector, 510 speed artifact, 565f, 566 speed of, 501f, 502–504, 503t, 505f system performance, 567f, 568–571, 568f, 571t three-dimensional imaging, 560, 561f transducer, 513–519, 513f, 514f, 515f, 516f transmit/receive switch, 529 two-dimensional image display and storage, 536–542 ultrasound contrast agents, 555–556 wave interference patterns, 505f Ultrasound beam far field, 521 Fraunhofer region, 521 Fresnel region, 520 grating lobes, 523, 523f, 524f Huygen’s principle, 520 nearfield, 520–521, 521f properties of, 514 side lobes, 523, 523f, 524f spatial resolution, 524–527 Ultrasound imaging, 9–11, 10f Uncharged particle interaction, 36 Units, radiation See Radiation quantities U.S Food and Drug Administration Radiopharmaceuticals, regulation, 628 U.S Nuclear Regulatory Commission, 893–896 radiopharmaceuticals regulation, 663 regulation, ALARA principle, 896 regulatory dose limits and comparison to ICRP 103 recommended dose limits, 896t U.S Pharmacopeia (USP), 608 Use factor, radiation shielding, 861–862 Useful beam, sources of exposure, radiation protection, 856 V Variable frame rate, pulsed fluoroscopy, 293–294 Varying magnetic field effects, biological effects, magnetic resonance imaging, 497 Vector versus Scalar Quantities, 913–914, 914f Index 1029 Veiling glare, 122, 123, 287 Video cameras, fluoroscopy, 288–289, 288f Video interface, 117 Voltage, Bremsstrahlung spectrum, 171 Voltage ripple, x-ray, 197–198, 197f Volume coils, 489 Voxel volume computed tomography, 325–327, 325f magnetic resonance imaging, 461 W WAN See Wide area network Wavelength electromagnetic wave, 21 ultrasound, 501f, 502–504, 503t, 505f Wave-particle duality, 18–20 White noise, 87 Wide area network, 133, 138f Windowing, 127–128 Word, digital data representation, 105 Word mode, digital image formats in nuclear medicine, 698 Workload, radiographic, fluoroscopic, CT computed tomography, 867 radiation protection, 860 radiographic distribution, 861 Wrap-around artifacts, magnetic resonance imaging, 485–486, 485f Written directive, radiopharmaceuticals, 629–631 X Xenon detector, x-ray computed tomography, 640 X-ray collimator, 187, 188f emission, factors affecting, 202–206 exposure timing electronic switch/timer, 198 falling-load generator control circuit, 198–199 mechanical contactor switch, 198 phototimer switch, 198–199, 199f filtration, 189–190 generator components autotransformers, 191–194 diodes, 193 filament circuit, 177 rectifier circuit, 192 transformers, 191–194, 192f exposure timing, 176–177 line voltage compensation, 196 phototimer switch, 198–199, 199f types constant potential generator, 197, 197f, 198 inverter generator, 195, 195f single phase x-ray generator, 195, 197, 200 three-phase x-ray generator, 195 voltage ripple, 197–198, 197f positive beam limitation, 187 production bremsstrahlung process, 171–174, 172f, 173f x-ray spectrum, 174–175, 174t, 175f, 175t, 176f 1030 Index X-ray (Continued) tube anode angle, 181f, 182–184, 182f, 184f, 185f configuration, 180–182, 180f, 181f focal spot size, 182–184 heel effect, 184–185, 186f off-focus radiation, 185, 186f pinhole camera, 183, 185f rotating, 180–182, 181f slit camera, 183 star pattern, 184 stationary, 180–182 biased focusing cup, 178–179, 179f cathode, 177–179, 178f, 179f cathode block current, 176 getter circuit, 187 grid biased tube, 188 housing, 171, 176 mammography tube, 188 insert, 171, 177f leakage radiation, 187 port, 176 space charge effect, 178f thermionic emission, 177, 178f voltage, 176 X-ray beam filters, 171 X-ray cable sockets, 176 X-ray computed tomography detector type, 329–335 fan beam geometry, 316 filtered backprojection, 352–354, 353f, 354f, 355f Hounsfield units, 324 iterative reconstruction, 357–358, 357f, 358f partial volume, 368–369, 369f simple backprojection, 351–352, 352f, 353f third-generation, 371–372, 372f X-ray dosimetry absorbed dose, 386–387 CT See CT dosimetry dose estimation, 400 effective dose See Effective dose equivalent dose See equivalent dose Monte Carlo Dose computation, 382–383 organ doses See Organ dose X-ray generator, 171 X-ray spectrum, 174–175, 174t, 175f, 175t, 176f X-ray tube output, dose-related metrics, 377, 378f, 378t