Power Doppler assessment of overall disease activity in patients with rheumatoid arthritis

PURPOSE: To examine synovial vascularity and flow patterns in hand and wrist joints--metacarpophalangeal (MCP) joints and ulnar stiloid (USTL) regions--of patients with rheumatoid arthritis (RA) using power Doppler sonography (PDUS) and spectral Doppler analysis and to assess the accuracy of PDUS in detecting overall disease activity in RA patients. METHODS: Two hundred forty MCP joints and 48 USTL regions in 24 RA patients were examined. Patients were categorized into 2 groups--active and inactive--according to the American College of Rheumatology remission criteria. Resistance indexes (RIs) were measured. RESULTS: Flow signals were detected in 50 MCP joints (in 13 patients) and 24 USTL regions (in 16 patients) and spectral analysis was performed in 46 MCP joints (12 patients) and 23 USTL regions (16 patients). The sensitivity and specificity of PDUS in detecting disease activity in RA were 92% and 40%, respectively. There was a negative correlation between flow signal number and RI, with higher scores of flow signals corresponding to lower RIs. CONCLUSION: PDUS appears to be a reliable method for assessing inflammatory activity in rheumatoid synovium.