Doppler sonographic analysis of synovial vascularization in knee joints of patients with rheumatoid arthritis: increased color flow signals and reduced vascular resistance

Power Doppler and spectral Doppler measurements of knee-joint synovitis in rheumatoid arthritis patients with superficial pattern signals and in those with deep pattern signals

Power Doppler and spectral Doppler ultrasonography were used to scan 127 knee joints of 72 patients with rheumatoid arthritis (RA). Synovial effusion thickness and synovial proliferation (pannus) thickness, as well as the flow signal diameter, were measured on ultrasonogram prints of the power Doppler using digital calipers. In addition, color-flow signal grades on power Doppler and the resistance index (RI) values on spectral Doppler were evaluated. The values of these five variables were compared among 58 joints with superficial pattern flow signals and 69 joints with deep pattern flow signals. Compared with the joints with deep pattern signals, the joints with superficial pattern signals had significantly higher mean values of effusion thickness (P < 0.0001) and flow signal grades (P < 0.0001), and significantly lower mean RI (P < 0.0001). On the other hand, the joints with deep pattern signals had a significantly higher value of signal diameter (P = 0.0125) and had a trend to higher value of pannus thickness (P = 0.079) as well. Significant correlations were observed between effusion thickness and signal grades (P < 0.0001); effusion thickness and RI (P < 0.0001); signal diameter and pannus thickness (P = 0.0102); signal diameter and RI (P < 0.0001); and signal grades and RI (P < 0.0001). The ultrasonographic measurements of synovitis in RA patients provide valuable information on synovial inflammation.

Doppler sonographic comparative study on usefulness of synovial vascularity between knee and metacarpophalangeal joints for evaluation of articular inflammation in patients with rheumatoid arthritis treated by infliximab

We used Doppler sonography to evaluate the therapeutic effects of infliximab on the knee and metacarpophalangeal (MCP) joints of 10 patients with rheumatoid arthritis (RA), based on the color flow signals (CFS) and resistance index (RI) of synovial vascularity. After three injections of infliximab, we observed significant improvement in numbers of tender joints (P < 0.01), values of C-reactive protein (CRP) (P < 0.01), erythrocyte sedimentation rate (ESR) (P < 0.001), disease activity scores including tender joints, swollen joints, and ESR (DAS28-E3) (P < 0.0001), and CFS of knee (P < 0.001) and MCP (P < 0.05) joints. There was no significant improvement in RI values of knee or MCP joints after the therapy. We observed significant correlation between CFS of knee joints (knee-CFS) and values of CRP (P < 0.01), ESR (P < 0.01), and DAS28-E3 (P < 0.05), but not between CFS of MCP joints (MCP-CFS) and values of CRP, ESR, and DAS28-E3. However, no significant correlation was observed between 10 difference values (before values-after values) of CFS grades of knee or MCP joints and 10 difference values each of CRP, ESR, or DAS28-E3. The knee joints are more suitable than MCP joints for obtaining CFS in Doppler sonography, and are more useful than MCP joints for evaluation.

Comparison in values of color flow signals and vascular resistance of synovial vascularity demonstrated by Doppler sonography between knee and metacarpophalangeal joints of patients with rheumatoid arthritis

Synovial vascularity of 12 patients with rheumatoid arthritis (RA) was examined by Doppler sonography for color flow signals and vascular resistance on knee joints and metacarpophalangeal (MCP) joints, and the results were compared with each other and with C-reactive protein (CRP) levels of the patients. A significant correlation was observed between knee resistance index (RI) and MCP-RI (P = 0.0140), but not between knee color flow signals and MCP color flow signals (P = 0.1029). A significant correlation was also observed between knee color flow signals and knee RI (P = 0.0107), and knee pulsatility index (PI) (P = 0.0146). On the other hand, no correlation was observed between MCP color flow signals and MCP-RI (P = 0.828), and MCP-PI (P = 0.434). There was no significant correlation between CRP levels and grades of color flow signals, RI, and PI for both knee and MCP joints. Doppler sonographic evaluation of RI, especially knee RI, could be a useful marker for estimating synovial inflammation in RA patients.