Using Magnetic Resonance Angiography to Measure Abnormal Synovial Blood Vessels in Early Inflammatory Arthritis: A New Imaging Biomarker?

Abstract

Objective.To ascertain whether magnetic resonance angiography (MRA) can reliably detect synovial neovascularization in subjects with early inflammatory arthritis.Methods.Subjects with 6 weeks to 6 months of clinical evidence of inflammatory hand arthritis had a radiograph, power Doppler ultrasound (PDU) scan, magnetic resonance imaging (MRI), and contrast enhanced MRA performed on the more symptomatic hand. Ultrasound examination of the wrist and 2nd–5th metacarpophalangeal (MCP) joints was scored for erosions, synovial thickening, and synovial blood flow. MRI were assessed using the OMERACT Rheumatoid Arthritis MRI Score (RAMRIS). MRA was used to assess the number of abnormal vessels in the 2nd–5th MCP and in the wrist.Results.Of 30 subjects, 66.7% showed abnormal vasculature on MRA in the MCP and/or wrist; mean number of abnormal vessels was 5.24 (range 0–22). Number of abnormal vessels on MRA was strongly correlated with degree of blood flow seen in the corresponding area on PDU (r = 0.79, p ≤ 0.0001). The number of abnormal vessels was highly correlated with MRI MCP synovitis scores (r = 0.69, p ≤ 0.0001), MRI wrist synovitis scores (r = 0.73, p ≤ 0.0001), and ultrasound synovitis scores (r = 0.68, p ≤ 0.0001).Conclusion.In this cross-sectional pilot study, MRA identified abnormal vessels in patients with early inflammatory arthritis. This is the first report of MRA visualizing abnormal vessels in this patient population. If the degree of neovascularization in early inflammatory arthritis predicts disease course, MRA evidence of abnormal vessels could be a new imaging biomarker.