QUANTIFICATION OF RHEUMATOID SYNOVITIS BY MAGNETIC-RESONANCE-IMAGING

Objective. To develop a method for quantifying acute synovial inflammation in rheumatoid arthritis (RA), utilizing magnetic resonance imaging (MRI). Methods. Gadolinium-diethylenetriamine pentaacetic acid-enhanced MRI was performed in 21 patients with knee synovitis. Changes in synovial membrane signal intensity were identified and quantified by line profile analysis. Multiple synovial biopsies were obtained by a blind biopsy technique, and standard clinical and laboratory measurements of disease activity were recorded. Results. The rate of synovial membrane enhancement correlated with histologic features of acute inflammation (r = 0.63, P < 0.01), but not with clinical or laboratory assessments. Conclusion. Dynamic MRI is a valuable technique for assessing acute synovial inflammation in RA.