How much different is the semi-quantification of synovitis according to the ultrasound system and the blood flow...

To compare synovial blood flow scoring between different technologies and ultrasound (US) systems in active and inactive rheumatoid arthritis (RA).

Fifty-nine RA patients underwent B-mode, power Doppler (PD), colour Doppler (CD), B-Flow and High-Resolution (High-Res) PDI assessments of 6 joints with two US systems at two European centres. Each joint was semi-quantitatively scored for all ultrasound parameters. PD, CD and High-Res PDI synovial signal was also quantitatively scored.

Correlations between the total score of SH with system 1 and 2 were very high (≥ 0.90, p<0.0001). Baseline correlations between systems for PD and CD total scores were moderate to very high (0.44-0.96, p<0.05). At baseline, there were no significant differences between ultrasound systems for PD or CD semiquantitative-based total scores in active or inactive patients (p>0,05). B-Flow and High-Res total scores were significantly lower than PD or CD total scores (p<0.05).

A high-end and an entry-level US system were interchangeable for scoring SH and showed similar sensitivity and responsiveness in scoring synovial blood flow by PD and CD but not interchangeability. B-Flow and High-Res PDI were responsive, but they showed different sensitivity to detect synovial blood flow compared to conventional Doppler.