Magnetic resonance imaging-determined synovial membrane volume as a markerof 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 predi ctor of progressive joint destruction in rheumatoid arthritis (RA), Methods. Twenty-six patients with RA, randomized to receive disease-modifyi ng antirheumatic drug (DMARD) therapy alone (11 patients) or DMARDs in comb ination with oral prednisolone (15 patients), were followed up for 1 year w ith contrast-enhanced MRI of the dominant wrist (months 0, 3, 6, and 12), c onventional radiography (months 0 and 12), and clinical and biochemical exa minations. Bone erosion (by MRI and radiography) and synovial membrane volu mes (by MRI) were assessed, Results. Significant synovial membrane volume reductions were observed afte r 3 and 6 months in the DMARD + prednisolone group, and after 6 and 12 mont hs in the DMARD-alone group (P < 0.01-0.02, by Wilcoxon-Pratt analysis). Th e rate of erosive progression on MRI was highly correlated with baseline sc ores End, particularly, with area under the curve (AUC) values of synovial membrane volume (Spearman's a 0.69, P < 0.001), but not with baseline or AU C values of local or global clinical or biochemical parameters, or with pre dnisolone treatment. In none of 5 wrists with baseline volumes <5 cm(3), bu t in 8 of 10 wrists with baseline volumes greater than or equal to 10 cm(3) , erosive progression was found by MRI and/or radiography, indicating a pre dictive value of synovial membrane volumes. MRI was more sensitive than rad iography for the detection of progressive bone destruction (22 versus 12 ne w bone erosions). Conclusion. MRI-determined synovial membrane volumes are closely related to the rate of progressive joint destruction. Quantitative MRI assessment of synovitis may prove valuable as a marker of joint disease activity and a pr edictor of progressive joint destruction in RA.