Qualitative and quantitative analysis of wrist joint in rheumatoid arthritis by contrast-enhanced ultrasound and its clinical value

Abstract

Objective To evaluate the value of contrast-enhanced ultrasound (CEUS) in detection of synovial hyperplasia in wrist joint of patients with rheumatoid arthritis (RA) and to explore the correlation with disease activity. Methods Thirty-nine RA patients with their wrist involved were examined by CEUS. The imaging features of synovitis were observed and the analysis of time intensity curve (TIC) was performed by contrast dynamic software. Some quantitative parameters were obtained from these fitting curves including basic intensity (a0), increased intensity(a1), descending slope(a2), ascending slope(a3), time to peak (TTP), peak intensity (PI), actual peak intensity (PI-a0), arrival time (AT), and area under the curve (AUC). And the correlation between these parameters with clinical activity index was analyzed. Results 35.9% (14/39) synovitis showed a centripetal enhancement pattern supplied by ring-like or arc-shaped arterials peripherally while 64.1% (25/39) showed diffusely entire enhancement. All the lesions were heterogeneous enhanced, 87.2% (34/39) of which exhibited hyperenhancement. The detection rate of perfusion defects was 41.0% (16/39). The disease activity in the diffuse enhancement group was higher than that in the centripetal enhancement group (4.64±1.09 vs 3.69±0.67, P=0.005). CEUS quantitative parameters a3 and (PI-a0) were positively correlated with erythrocyte sedimentation rate (ESR) (r=0.465, P=0.006; r=0.325, P=0.043), however TTP had a negative relationship (r=-0.352, P=0.041). Conclusions Active synovitis usually represents as a diffuse enhancement pattern. A higher a3 and PI, and a shorter TTP indicate a higher disease activity. CEUS plays a great role in monitoring RA disease activity both from qualitative and quantitative aspect. Key words: Contrast-enhanced ultrasonography; Arthritis, rheumatoid; Synovitis; Musculoskeletal ultrasound