Magnetic resonance imaging–determined synovial membrane volume as a marker of disease activity and a predictor of progressive joint destruction in the wrists of patients with rheumatoid arthritis

Objective To evaluate the synovial membrane volume, determined by magnetic resonance imaging (MRI), as a marker of joint disease activity and a predictor of progressive joint destruction in rheumatoid arthritis (RA). Methods Twenty‐six patients with RA, randomized to receive disease‐modifying antirheumatic drug (DMARD) therapy alone (11 patients) or DMARDs in combination with oral prednisolone (15 patients), were followed up for 1 year with contrast‐enhanced MRI of the dominant wrist (months 0, 3, 6, and 12), conventional radiography (months 0 and 12), and clinical and biochemical examinations. Bone erosion (by MRI and radiography) and synovial membrane volumes (by MRI) were assessed. Results Significant synovial membrane volume reductions were observed after 3 and 6 months in the DMARD + prednisolone group, and after 6 and 12 months in the DMARD‐alone group (P < 0.01–0.02, by Wilcoxon‐Pratt analysis). The rate of erosive progression on MRI was highly correlated with baseline scores and, particularly, with area under the curve (AUC) values of synovial membrane volume (Spearman's σ = 0.69, P < 0.001), but not with baseline or AUC values of local or global clinical or biochemical parameters, or with prednisolone treatment. In none of 5 wrists with baseline volumes