What an MRI Can Tell You About Rheumatoid Arthritis
Rheumatoid arthritis is an autoimmune disease that affects the lining of your joints. When you have rheumatoid arthritis, your immune system mistakenly attacks its own tissues, leading to painful, swollen joints; the inflammation produced can even affect other systems of your body. For many years, doctors relied on blood tests and x-rays to make a diagnosis of rheumatoid arthritis. While these tools are still routinely used, advanced imaging systems like MRI (magnetic resonance imaging) may allow for an earlier diagnosis and treatment of this disease.
What’s happening in your body when you have rheumatoid arthritis?
Rheumatoid arthritis generally occurs on both sides of your body. It often starts in your smaller joints, like your fingers or toes, and may spread to bigger joints as the disease progresses. While we don’t know what actually triggers the start of the disease, we do know your immune system cells attack the synovium, the lining of your joints, causing inflammation. This inflammation creates the uncomfortable symptoms of pain, swelling, and stiffness in your joints. If this persists over time, it can lead to permanent damage in the cartilage, tendons, and bones of the affected joints.
Blood tests can be ordered to check for the presence of antibodies involved in the immune response or to measure inflammation within the body. X-rays can show bone erosions, or loss of bone within the joint, and narrowing of the joint spaces.
But if your rheumatoid arthritis is still in its early stages, these changes may not yet be seen on x-ray. This is where MRI can be useful. MRI may show other changes in the joint that occur earlier in the disease process, allowing your doctor to detect it sooner.
What does rheumatoid arthritis look like on an MRI?
MRI provides very detailed pictures of your organs, tissues, and bones by using a strong magnet, radio waves, and a computer. With these clear images, bone erosions in your joints can be more easily identified on MRI than on x-ray.
MRI can also reveal issues within the joints that are unable to be seen on x-ray. Two features of rheumatoid arthritis that your doctor may look for include:
Inflammation: MRI can show inflammation of the lining of your joints, known as synovitis. This is an early sign of rheumatoid arthritis.
Bone marrow edema: This occurs when excess fluid builds up in your bone marrow. If bone marrow edema is present, it’s often an indicator of eventual bone erosions.
Bone erosions, inflammation, and bone marrow edema on MRI can help diagnose rheumatoid arthritis in its early stages.
Why is early diagnosis of rheumatoid arthritis important?
Treatment for rheumatoid arthritis has come a long way, especially with the development of a type of medication known as disease-modifying antirheumatic drugs (DMARDs). But DMARDs work best when rheumatoid arthritis is caught early and treatment is initiated quickly. DMARDs can help decrease symptoms and slow the progression of rheumatoid arthritis, helping to avoid permanent damage to the joints and other parts of the body, such as the skin, eyes, lungs and heart. In some cases, DMARDs can even lead to remission from the disease. Common DMARDs include:
Methotrexate (Trexall, Otrexup, Rasuvo)
Newer DMARDs, known as biologics, are also available. These drugs, derived from living organisms, target specific parts of your immune system, attempting to stop the inflammatory response. Biologics prescribed for RA include:
Can MRI help determine the best treatment for you?
MRI can also be a useful tool for monitoring your response to treatment. After you have a baseline established, subsequent MRIs can determine the effectiveness of your current medication regimen by assessing if your inflammation or bone marrow edema is improving or worsening. Researchers are hopeful, as we learn more about using MRI to guide treatment decisions, eventually systems can be developed to help newly diagnosed individuals determine what types of treatment will work best for them.
The trade-off is MRIs are expensive and require specially trained doctors to interpret them. Other imaging systems like ultrasound may be able to provide important information as well, and ultrasound is often more readily available and more cost effective. Further research and time will help decide the best method of diagnosing and evaluating rheumatoid arthritis. If you have rheumatoid arthritis, or are concerned that you might, ask your doctor if any advanced imaging systems can be helpful in your diagnosis and treatment.