To compare colour Doppler (CD) versus power Doppler (PD) semiquantitative and quantitative scoring of synovial vascularisation and to evaluate the relationship between semiquantitative and quantitative scores in patients with rheumatoid arthritis (RA).
One hundred RA patients underwent B-mode, PD, and CD assessments of 12 joints at two European centres. Each joint with synovial hypertrophy (SH) detected on B-mode was semiquantitatively scored (0-3) for PD (SPD score) and CD (SCD score) synovial signal. PD and CD synovial signal were also quantitatively scored (0-100%) (QPD and QCD scores, respectively) using a software integrated in the US equipment for counting the colour fraction.
We found SH in 184 joints. SPD and SCD agreed in 92.3% (95%CI: 88.4; 96.2%) of paired scores, with Kendall rank correlation coefficient tau-b=0.95. QPD and QCD scores were highly correlated (Pearson's coefficient=0.70) but Blamd-Altman plot showed insufficient agreement, being the QCD scores systematically slightly higher than the QPD scores. The comparison of mean values of QPD and QCD between scores of SPD and SCD, respectively, showed significant differences between grade 0 and grade 1 (p<0.001), and grade 2 and grade 3 (p=0.042 and p=0.007, respectively) but not between grade 1 and 2 (p=0.154 and p=0.150, respectively).
The SPD and SCD scores were concordant and the QPD and QCD scores highly correlated but were not concordant. There was an overlap between SPD and SCD mild and moderate scores regarding QPD and QCD scores.