Power Doppler sonography for detection of intraarticular vascularization in knee joints of patients with rheumatoid arthritis.

A series of 47 knee joints in 24 patients with rheumatoid arthritis were examined for intraarticular vascularization by power Doppler sonography. The intensity of vascularization was compared with the synovial effusion and proliferation evaluated by gray-scale sonography and the clinical findings in the patients. Vascularization was graded from 0 to 3 by counting the number of color-flow signals: grade 0, no signals; grade one, 1-4 signals; grade two, 5-8 signals; grade three, 9 or more signals. The grade of vascularization correlated with the grade of synovial effusion (P < 0.01), the grade of synovial proliferation (P < 0.05), and the serum levels of C-reactive protein (P < 0.05). It correlated inversely with disease duration (P < 0.01). Consistent with improvement of articular inflammation, a decrease in the number of color-flow signals was observed in two patients. Power Doppler sonography is suitable for evaluating the intensity of synovitis and for monitoring the clinical activity of rheumatoid patients.