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THURSDAY, July 3, 2003 (HealthDayNews) -- When patients are first diagnosed with rheumatoid arthritis (RA), it's often difficult for doctors to predict what their future holds: Some will have only mild symptoms, while others will be disabled by the disease.
But a new study now says magnetic resonance imaging (MRI) may predict who will have an aggressive form of RA, letting doctors target the strongest medicines to the patients who really need it.
The six-year study, which appears in the July issue of Arthritis and Rheumatism, found patients who had bone swelling at the start of the project were 6.5 times more likely to have serious joint damage at the end of the study.
"MRI is proving to be a useful tool with which to investigate disease processes in RA," study author Dr. Fiona McQueen, from Auckland Hospital in New Zealand, says in a news release.
Rheumatology experts aren't so sure, however. Both Dr. Robert Quinet, chairman of rheumatology at Ochsner Clinic Foundation in New Orleans, and Dr. Martin Pevzner, chairman of rheumatology at Beaumont Hospital in Royal Oak, Mich., feel MRIs are too expensive to be used as screening tools.
"The problem is MRIs are so expensive, insurance companies often won't cover them," Pevzner says. And Quinet echoes that thought, adding there are other, less expensive tests that can be used to predict what course an individual's RA might take. These include blood tests, X-rays and functional assessment questionnaires.
But, Pevzner concedes, those tests are not "an exact science" and there currently is no "definitive predictor."
Rheumatoid arthritis affects 2.1 million Americans, according to the Arthritis Foundation. Nearly three times as many women as men are affected by the disease. Its symptoms include joint pain, stiffness, swelling and redness, and it usually appears in middle age, but can begin earlier. In some people, rheumatoid arthritis is so severe it actually destroys the bone and cartilage in affected joints.
For this study, McQueen and her colleagues recruited 42 people who were in the early stages of RA. All of the volunteers had an MRI and an X-ray of the wrist in their dominant hand. The tests were repeated at one year and at six years. At the six-year follow-up, only 31 of the original participants were able to be included.
MRI is an imaging technique that uses magnetic field and radio waves to produce precise images of the body; it gives doctors more detailed images than X-rays.
The people who showed signs of bone swelling in the first MRI scan were the most likely to have developed bone erosion by the end of the study.
The study also found MRIs were more effective at picking up bone erosion than X-rays. The first MRIs showed bone erosion in 45 percent of the study participants, compared to only 15 percent found in X-rays.
"There are some innovative aspects to this study," says Quinet, who cites the long follow-up of patients and the way the researchers correlated their MRI findings with X-rays. But he adds, "In terms of its application, I don't think it will have a major impact now. It has potential for the future."
Pevzner agrees, saying, "In the future, it may provide another clue to who needs aggressive treatment."
That's important, he adds, because early intervention helps control the disease and limits its damage.