M.R.I.'s ~ The Scan That Didn't Scan: different conclusions/how skilled is the radiologist who reads your scans/C.T. scans or X-rays .. NY Times 10/14/08

[Guest guest]

http://www.nytimes.com/2008/10/14/health/14scan.html The Scan That

Didn’t Scan By GINA

KOLATA NY Times October 14, 2008 This is a story about M.R.I.’s, those amazing scans that

can show tissue injury and bone damage, inflammation and fluid accumulation.

Except when they can’t and you think they can. I found out about

magnetic resonance imaging tests when I injured my forefoot running. All of a

sudden, halfway through a run, my foot hurt so much that I had to stop. But an M.R.I. at a

local radiology center found nothing wrong. That, of course, was

what I wanted to hear. So I spent five days waiting for it to feel better,

taking the anti-inflammatory drugs ibuprofen and naproxen, using an elliptical

cross-trainer, and riding my road bike with its clipless pedals that attach

themselves to my bicycling shoes. By then, my foot hurt so much I had to walk

on my heel. I was beginning to doubt that scan: it was hard to believe nothing

was wrong. So I went to the Hospital for Special Surgery in

New York for a second opinion from Dr.

G. Kennedy, an orthopedist who specializes in sports-related lower-limb

injuries. And there I had another M.R.I. It showed a serious stress fracture, a

hairline crack in a metatarsal bone in my forefoot. It was so serious, in fact,

that Dr. Kennedy warned that I risked surgery if I continued activities like

cycling and the elliptical cross-trainer, which make such injuries worse. And I

had to stop taking anti-inflammatory drugs, since they impede bone healing. As I hobbled around

the office on crutches, one of my colleagues, Glanz, asked what had happened.

As we chatted, it turned out that he had had a much more sobering experience

than mine. Jim, the

Baghdad bureau chief for The New York Times, was playing

touch football in New York in late 2005 when he landed hard while diving to make a catch, both elbows

hitting the ground at once. The next day, his fingers and hands hurt so much he

couldn’t type. But an M.R.I. showed

nothing except some bulging disks in his neck that, he was told, were common in

people his age, 50. He was advised to do neck exercises, and eventually he felt

better. About a year later, he

fell again while playing football. His symptoms came roaring back. The worst was when he

woke up in the morning, Jim said. The two middle fingers on each hand were so

stiff they would not even bend. He would massage his fingers and loosen them,

but his hands and knuckles ached all day. He tried ibuprofen, to little avail. Finally, last spring,

he sought help at New York University, where he had another

M.R.I. It turned out he had a nerve impingement so serious that he was warned

that he risked permanent paralysis if he did not

have surgery. So this summer, he had a major operation called a French-door

laminoplasty, in which his surgeon, Dr. Moskovich at the N.Y.U. Hospital

for Joint Diseases, opened and widened four or five vertebrae to free the

trapped nerves. How could

M.R.I.’s have come to such different conclusions for both Jim and me? Jim asked his doctors

whether he could have really had nothing wrong at the time of his first scan.

Unlikely, they replied, although they cautioned that no one had directly

compared the two scans. I asked Dr. Kennedy

the same question and received the same answer. He explained that in my case

the quality of the two images was vastly different. “It’s like the

difference between a black-and-white TV and HDTV,” he said. All well and good, but

how was I supposed to know? The radiology center I first went to is accredited

by the American

College of Radiology, and there is no

way I can tell a good M.R.I. image from a bad one. In fact, I never even saw

the images. All I saw were the radiologists’ reports. Academic radiologists

say that, unfortunately, they see patients like Jim and me all the time. “That’s

the bane of our existence in an academic medical center,” said Dr.

P. Forman, a professor of diagnostic radiology at Yale University School of Medicine. And it’s not

just patients who have to deal with the problem, said Dr. C. Black, a

professor of radiology and community and family medicine at

Dartmouth Medical School . Doctors do, too.

Radiology centers send written reports to doctors, but the doctors may have no

idea whether the M.R.I. was done well and interpreted well. “It’s a

huge problem,” Dr. Black said. Unlike C.T. scans or

X-rays, which transmit radiation through the body to produce images,

M.R.I.’s use powerful magnets and radio waves to manipulate protons in

the body’s hydrogen atoms. The idea, said Dr. H. Haims, a

diagnostic radiologist at Yale, is that protons in different types of tissue

respond in distinctive ways to this pushing and prodding. The differing

responses reveal the characteristics of the tissue. Magnetic resonance

machines, though, vary enormously, and not just in the strength of their

magnets. Even more important, radiologists say, is the quality of the imaging

coils they put around the body part being scanned and the computer programs

they use to control the imaging and to analyze the images. And there is a huge

variability in skill among the technicians doing the scans. Dr. Forman said that

at the very least, patients should go to radiology centers accredited by the

American

College of Radiology. But he added that accreditation

does not tell you whether your scan will be done with a machine that is several

generations removed from the best available today; whether the scanning is

programmed to pick up your particular problem; or whether the receiving coil

that picks up signals from the magnet is sufficiently sensitive. G. Gazelle, a

professor of radiology at Harvard Medical School ,

shared Dr. Forman’s opinions. “People

don’t understand that there are these differences,” he said, adding

that radiology centers that do not keep up will be doing a less than ideal job.

“The pace of technology development is staggering,” he said. Then there is the

question of how skilled is the radiologist who reads your scans. At Massachusetts General Hospital, for

example, Dr. Gazelle said, “musculoskeletal M.R.I.’s are read by

someone who does musculoskeletal imaging every day” — and not

“by someone who reads chest M.R.I.’s one day and musculoskeletal

M.R.I.’s the next.” Dr. Forman says it

pays to check the credentials of a center’s radiologists. “If you say,

‘Who will be reading my scan?’ and they say, ‘One of our

radiologists,’ you don’t go to a place like that,” he said.

(I checked the Web site of the first center I went to. The radiologist who read

my scan was a generalist with no special training.) Of course, it may not

be feasible to go to an academic medical center where subspecialists will read

your images. And even if you do, said Dr. Thrall, chairman of the board

of chancellors of the American College of Radiology, “scans, as good as

they are, are not perfect.” ”I

wouldn’t equate a negative scan as being an 100 percent indicator that

nothing is wrong,” he added. So if you are told nothing is wrong because

a scan was negative and you are having alarming symptoms, you may want to seek

a second opinion. And don’t

forget, said Dr. Jarvik, a professor of radiology and neurological

surgery at the University of Washington, the point of an

M.R.I., or any imaging study, is to help make a diagnosis that will improve

your health. Often imaging is unnecessary: a good exam will reveal what’s

wrong, and the treatment will be the same with or without the scan. Just as big a problem

as the erratic quality of scans is the tendency of doctors and patients to rely

on them too much. “There’s

been a shift in medicine toward relying on imaging instead of a history and

examination,” Dr. Jarvik said. And I suspect that

that was one reason Jim and I were so misled. “Pain is a way

for Mother Nature to talk to us,” Dr. Thrall told me. “And when our

invented process for understanding is at odds with what Mother Nature is

telling us, we had better listen to Mother Nature.”