Table Of ContentHow X-
CT, MRI
Ultrasound,
and Other
Medical
Images Are
Created rt and How
They Help
Physicians
ANTHONY BRINTON WOLBARST
Looking Within
‘Thepublae grat
achnoledes the generous
contrition this bok
Provided bythe General
ndoeoment Ferd
Ihe Ascites of the
nicer of California Press
Looking Within
How X-Ray, CT, MRI, Ultrasound,
and Other Medical Images Are Created,
and How They Help Physicians Save Lives
ANTHONY BRINTON WOLBARST
Iustrtons by Gordon Cook
UNIVERSITY OF CALIFORNIA PRESS
Nesey Las Angle Landon
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eyed angi aoa
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For Eleanor
"She openeth her mouth with wisdom;
and inher tongue isthe law of kindness”
Proverbs
Contents
Acknowledgments
Preface
From the Watching of Shadows
Shadows on X-Ray Fim: Radlography / Mammography
Shadows on Telviion tv: Foroscopy
Shadows in Computers: Going Dita
‘ices of Life: Computed Tomography (CT)
Uke Embers nthe Darke Nuclear Medicine
Shadows rom Echoes: Utrasound
‘AWatery Miror: Magnetic Resonance Imaging (MR)
Eploge: Looking Forward
‘Append A Protons, Protas, ond A Tho:
A Brief Review of Atoms and Rediton 177
‘Aopend 8. More bout MRI:
1 and Poon Spin Relaxation 183
Notes 197
Sugestons fr Forte Reading 99
Index 201
Acknowledgments
“Many people have helped me with this undertaking, and Tam extremely
satel forthe time and thought they contributed tot They fallinto three
general groups: physicians, medical physicists, and family nd friends
‘ot professionally involved with medicine
Gregory Curt, clinical director of the National Cancer Institute, led me
In the construction of about half ofthe patient ease studies. Thanks, Greg,
Je was fn, and it was great to hea it from sucha wonderful guide.
‘Three radiologists John Chotkowsli, Will McCann, and Dennis Patton,
sand especially an internist, Kevin Nealon, read the whole manuscript
carefully and provided valuable input. Bruce Bowen and Mohsen Gharib,
also radiologists, kindly gave me the elie images and the interpreta.
tions of them that [used inputting together several ofthe casestudies.
Robert Zamenhof, a medial physicist who taught me much of what 1
know ofthe physics imaging, scrutinized all of Laoting Within—twice—
with his usual insight and good humor, nd offered many ideas fo im-
provements. Seong K. Mun and Allan Richardson aio gave it care,
reading, and my thesis advisr, Bill Doyle, commented on the pars on
“MRI Steve Bacharach provideda very helpfl update on clinical PET; Al-
lan Cormack on several occasions talked with me about the easy days of
(CTyand Bll endee made sensible (as always) suggestions concerning my
speculations onthe future of imaging in chapter 9.
Several family members and other good frends who are not medially
Inclined were wiling to be voluntered to read the manuscript from the
point of view of nonmedical people. They found many areas that needed
simplification or more lucid explanation, and their observations helped
me eliminate a numberof stumbling blocks. My thanks to Pete Detgen Jay
Hardgrove, Peter Head, Tom Fisher, Joe Mazzet, and especally to my
‘eatiful and clever country cousin, Ramsey Ludlow Sherratt, who sid,
tall the right places, "'m ust not sure this is completely cleat.”
‘ran into Dana (Hastings) Murphy onthe Metro, and she's just as sharp
and funny as when she was freshman at Smith those few yeas ago. Dana
agreed todo some sanding and polishing and, as result, Loking Within s
good deal more readable than before she got tot. My copy editor atthe
University of California Pres, Madeleine Adams, alo did a splendid job
in that regard,
‘Two people helped to turn what sometimes fl lke to years at hard
labor into a pleasure. My editor at the University of California Pres,
Howard Boyer, isa wise and supportive counselor, and has become a
{00d frend. So also Gordon Cook, a gentle and amusing guy who isa de-
light to work with, and whose drawings (bth here and in my PysesofRa-
ology) are nothing shor of superb.
‘A number of physicians and other medical professionals took time
from ther busy schedules to respond to my requests for photographs.
have acknowledged them in the fgure captions but I also want to give
them my deep thanks here. In selecting photograph from among those
sent by equipment manufacturers, Ihave attempted to achieve a fair and
representative balance—weighted somewhat, admit, bythe degree to
‘which they made serious efforts to provide images appropriate for «book
such this. But most important, Ihave chosen the photos that feel most
clearly illustrate the point. In no case should the wie ofa photograph be
Interpreted a an endorsement of a product.
ave tied hard to ensure the accuracy of what Ihave written, but may
Ihave et some erors creep in. Or a5 we say in Washington, mistakes may
have been made. I would appreciate hearing fom readers who ind any.
Finally, offer my deepest appreciation and my love to Eleanor Nealon, my
‘ride ofa dozen years. Shes one tough literary ec, the coauthor of my
‘reams, andthe loveliest lady know. Heanor, thank you for sharing yout
life with me.
Preface
‘Acentury ago, doctor had no vay to view the inside ofa patient's body
other than to cu it open.
‘That changed literally overnight on th evening of November 8 805,
‘when Wilhelm Conrad Roentgen happened upon X rays. His extrordl
rary and mysterious radiation immediately covered the front pages of
revespapers everywhere, and within months physicians throughout the
‘world were using the pictures it produced to set broken bones and remove
bullets. Roentgen had found “anew kind of ras,” ase called them—and
{nso doing, he had discovered a splendid window for looking within the
body and painlessly examining the organs and bones.
‘Medical imaging evlved steadily bt slowly fom then until the 5708
sas researchers continually devised better ways to provide linia infor
‘mation. The developments over the past few decades, by contrast, have
‘been nothing short of revolutionary. Made possible and driven largely by
the availablity of powerfl and inexpensive computers, computed
‘ography (CT) and then magnetic resonance imaging (MRI) have radi
cally altered patient treatment and, beyond that even the ways in which
physicians perceive and think about the body.
‘American health care providers now perform over a quate billion
imaging examinations annualy—one ayer for every man, woman, and
child, on average—and the curious among us would natural lke to know
how those studies are made and what they are doing for and ows. Look
ing Witinis intended to explain how X-ray, marnmography, CT, MRI. nu:
lear medicine, ultrasound, and other medical images are created and
