Quantitative power Doppler signal assessment in the subchondral bone region of the metacarpophalangeal joint is an effective predictor of radiographic progression in the hand of rheumatoid arthritis: a pilot study

Ultrasonography is useful for assessment of synovitis in the hand of rheumatoid arthritis (RA) patients. The aim of this study was to investigate the predictive value of the quantitative power Doppler (PD) signal assessment in the subchondral bone region of the metacarpophalangeal (MCP) joint in patients with RA showing radiographic progression of the hand by comparing with those of previously reported scoring systems. Twenty-two patients (20 women) with RA who underwent power Doppler ultrasonography (PDUS) of the bilateral one to five MCP joints at baseline were included in the study. Radiography of both hands was performed at baseline and at 1year. PDUS of the synovial space was evaluated according to semi-quantitative scoring (0-3) and quantitative measurement (0-100%). The PD signal in the subchondral bone region was qualitatively (0, 1) and quantitatively (mm(2)) assessed. The performance of PDUS assessment was compared using the area under the curve (AUC) of the receiver operating characteristic (ROC) curve and the risk ratio (RR). As a predictor for radiographic progression, the quantitative PD signal assessment in the subchondral bone region (AUC=0.842, p<0.01) was equivalent to quantitative vascularity (AUC=0.817, p<0.05) and semi-quantitative scoring (AUC=0.754, p<0.05). As for the RR of the PD signal in the subchondral bone region for radiographic progression, the quantitative PD signal assessment was 5.40 (p