Why the X-Ray Is Superior to the MRI in Rheumatoid Arthritis, For Now
While the traditional x-ray is still the radiologic tool most used by rheumatologists to diagnose rheumatoid arthritis, magnetic resonance imaging (MRI) has slowly but surely developed a following among some rheumatologists. This is because MRI studies can show much more detail than the plain x-ray.
The question, however, remains to be answered: Does the use of MRI change how a rheumatologist treats his patients, the ultimate goal being the achievement of remission?
Traditional x-rays are often preferred when investigating presumed damaged joints, for obvious reasons: x-rays are much less expensive, much more available, easy to perform, and acceptable to most patients. On the other hand, full-body MRI studies are generally not immediately available, often require insurance approval, and are dreaded by the more claustrophobic patients.
So-called "peripheral MRIs" are an alternative to the coffin-like image that is conjured up when many of us hear the letters "M" "R" "I". The peripheral MRI is a much smaller machine, and portable. It allows for the targeted examination of joints: a patient is able to place his hand or foot into the machine, avoiding having to crawl into the tube of the full MRI machines: this is not only less expensive, potentially allowing for greater use of MRI, but it also solves the claustrophobia problem.
Despite the advances in MRI machine design, experts, including those representing the viewpoint of the American College of Rheumatology, have their doubts about the true usefulness of the MRI in evaluating and treating rheumatoid arthritis.
These experts feel that x-rays and a thorough history and physical examination offer as much practical information as the MRI studies.
However, other rheumatoid arthritis experts feel the peripheral MRI should be used more frequently in the typical rheumatologist's practice. These experts feel that the MRI can provide evidence of more serious bone destruction before it becomes evident on a plain x-ray; this information in turn helps the treating rheumatologist to decide how aggressive to be in terms of treatment. For example, more serious disease deserves early and more aggressive intervention. These same experts believe that the cost of the MRI should not be a consideration, as the cost of incorrectly treating a rheumatoid arthritis patient can be rather high. Such costs can include the disability from deformities in a patient who may have avoided this fate if the rheumatologist had had the information to justify early aggressive treatment with biologic agents.
There is much evidence showing that patients who begin anti-tumor necrosis factor treatments early can experience remission of their disease compared to patients taking the more traditional disease-modifying drugs. But there is also evidence that these MRI studies are showing destructive bone changes even in patients who do not have a joint disease.
The bottom line here is that the debate on the need for the MRI in the treatment of rheumatoid arthritis is far from over. More studies need to be done. In my opinion, this need in and of itself indicates to me that the MRI is not ready for the doctor's office.