Michael H. Weisman, MD, director of the division of rheumatology at Cedar Sinai Medical Center in Los Angeles, argued that peripheral MRIs should not be part of common practice in dealing with RA until the devices are proven to be better diagnostic tools. He says that the added expense of peripheral MRI does not yet appear to outweigh the information that can be gathered by traditional x-rays, CT scans, and physical examination methods. He acknowledged that MRIs would allow doctors to see some new details, such as inflammation of the synovium, but biopsies can also reveal such information. Dr. Weisman considered the advantages of the information obtained from a more expensive MRI machine with that from the less expensive approach.
Bone erosion is another area where MRI images seem to be of potential usefulness. Dr. Weisman said that bone erosions appear earlier on MRIs and often in greater numbers than those seen on x-rays. However, he cautioned that these MRI images do not fepict well the boundaries of bone erosion. On x-rays and CT scans, bone appears bright, but it tends to fade in MRI-produced images. There also appears to be no information on whether these MRI devices can distinguish between RA and other diseases found in the joint.
The question facing rheumatologists is whether this added level of sensitivity moves diagnosis or treatment of RA patients forward enough.
Some In Favor of the Technology
Despite the questions, some rheumatologists believe peripheral MRIs should be utilized more widely in common practice. Paul Emery, MA, MD, of Leeds University in England, supports integrating peripheral MRIs into rheumatology practice now. He acknowledges that some questions remain, but that overall, MRI provides detailed images that may be the difference between simply managing an illness and putting a disease into remission.
Cost, when compared with traditional x-rays, should not be a consideration when trying to provide patients with the fastest and most accurate diagnosis of the earliest stages of RA, Dr. Emery said. “The cost of mismanaging a patient is extraordinarily high,” he noted.
A key advantage of MRI is its ability to detect changes in the joint before they become visible on x-rays. Such a head start can be critical for determining which patients would most benefit from biologic treatments. Putting patients on biologics early can make a long-term difference in managing RA, said Dr. Emery.
Britain’s National Health Service has already accepted the benefits of peripheral MRI and allows their use by doctors as a diagnostic tool, Dr. Emery noted.
