Advanced Power Doppler Technique Increases Synovial Vascularity Detection in Patients with Rheumatoid Arthritis

We compared the diagnostic performance of an advanced power Doppler technique (superb microvascular imaging [SMI]) with that of power Doppler Imaging (PDI) and B-mode ultrasound (US) in patients with early rheumatoid arthritis (RA) and RA under treatment with rituximab. Thirty patients (21 women aged 45 ± 11 y) affected by RA with remission to moderate disease activity were examined. Both hand joints were evaluated using US, PDI and SMI. Two radiologists reviewed all video clips and evaluated synovial vascularity intensity using a semi-quantitative scoring system. SMI revealed the presence of synovial vascularity in a significantly larger number of patients than PDI (p = 0.02). Inter-observer agreement for US, PDI and SMI was moderate (κ = 0.59), very good (κ = 0.87) and very good (κ = 0.82), respectively. We conclude that SMI detects more vessels than PDI in RA patients. This may allow increased sensitivity for early diagnosis of synovial inflammation, monitoring of its dynamic changes under therapy and evaluation of true imaging remission.