Objective: To assess the efficacy of magnetic resonance imaging (MRI) in objectively defining a state of remission in rheumatoid arthritis (RA) after treatment.
Methods: Ten patients with RA involving the wrist were evaluated before treatment with methotrexate and hydroxychloroquine, and then mean 14 mo later with a followup evaluation. Clinical variables, laboratory measurements, and MRI using various techniques (T1 weighted image, T2 weighted image, fat suppression T2 weighted image, postcontrast T1 weighted image, postcontrast dynamic image, postcontrast 3 dimensional image) were observed. Remission was defined by ACR criteria. MRI changes were observed using 3 variables: extent of synovial proliferation; extent of bone marrow edema; and development of new erosion. In 6 of 10 patients, synovial signal intensity time curve changes at 30 s (E30 ratio) were determined for quantitative assessment of synovitis.
Results: Four patients achieved remission and 6 did not. All patients in remission showed decrease in extent of synovial proliferation and bone marrow edema with no newly developed erosion after treatment, compared to baseline. Five of 6 patients in nonremission showed newly developed erosions with variable changes in extent of synovial proliferation and bone marrow edema. E30 ratio was determined in 3 patients in the remission group and 3 in the nonremission group, with 48% reduction in the former compared to 9% reduction in the latter.
Conclusion: MRI is feasible for objectively defining remission and assessing the therapeutic effect of antirheumatic drugs; utility of MRI measures in clinical remission criteria remains to be verified.