That's the conclusion of a new study, which acknowledges that rapid magnetic resonance imaging (MRI) tests may provide physicians a clearer view of the anatomy than an X-ray, and quickly. However, their use doesn't help resolve back problems. In fact, the researchers say the costly MRIs are much more likely than X-rays to lead to disc surgery, a procedure with limited value to all but a few people with low back pain.

"MRI scanning clearly is an important imaging method for the spine and it gives us some of the best pictures we have of the anatomy. But unfortunately the anatomy doesn't always match very closely with peoples' symptoms," says study co-author Dr. Richard Deyo, a professor of medicine at the University of Washington in Seattle. "It really is a much better picture, but sometimes a picture is more than you want to know."

Deyo's group reports its finding in the June 4 issue of the Journal of the American Medical Association. The study looked at a relatively new form of MRI called rapid MRI, which is similar to the conventional imaging test but takes only a fraction of the time to conduct. In the process, it provides detailed pictures of the anatomy that X-rays can't touch.

The study followed 380 men and women with low back pain who were being seen at Seattle-area clinics. Half underwent rapid MRI as a first resort, while the rest had more conservative spinal X-rays to detect the cause of their discomfort.

After a year, most patients had improved significantly. Yet the two groups were equally likely to report continued back disability, back pain and other measures of distress. That suggests the group that got rapid MRI wasn't receiving more finely tuned treatment, Deyo says.

However, those who had the MRI test were 2.5 times as likely to have undergone spinal surgery to correct a problem than those in the X-ray group -- 10 people versus four.

Dr. Jeffrey Jarvik, a neurosurgeon at the University of Washington and lead author of the study, says he was somewhat surprised by the results: "I really thought the rapid [MRI] might in fact improve patient outcomes, or at least there might not be the suggestion that it was a more expensive alternative."

By doing an early scan, Jarvik says, the hope was to rule out serious problems and avoid more expensive tests later on. That happened to a degree, he adds, but it was more than outweighed by the additional back surgeries.

Dr. Nortin Hadler says back surgery should be consigned to the waste bin of medical procedures. "There's absolutely no evidence that it works," says Hadler, a professor of medicine at the University of North Carolina and author of an editorial accompanying the journal article. "It ought to be a vanishingly rare procedure."

Hadler, who is wary of the perpetual "medicalization" of minor complaints, says most Americans experience major back pain at least once a year and almost every adult has some spine abnormalities. "Once you show someone that anomaly on the MRI it grows in their mind, and it's hard for them to think that it's not meaningful," he says.

Doctors need to do a better job of helping people cope with problems such as back pain that are uncomfortable but almost always minor, Hadler says. "My hope is some day a patient can go to an American doctor and say, 'My back is killing me, but I want to make sure there's nothing special here so I can cope with the pain.'"

More information

To learn more about back pain and what to do for it, try the National Institutes of Health or the Neurology Channel.