Objective: To study the value of 3 T dynamic contrast-enhanced (DCE)-MRI for assessment of synovitis of the interphalangeal joints in patients with erosive osteoarthritis (EOA) for treatment response monitoring.
Materials and methods: The interphalangeal joints of fingers two to five were examined at 3 T MRI in nine patients with EOA. Two musculoskeletal radiologists recorded erosions, bone marrow oedema (BME), synovitis and osteophytes. Interobserver reliability was calculated using κ statistics. In six patients, DCE-MRI time intensity curves of synovitis in two affected joints were analysed. The maximum upslope, absolute and relative enhancement of synovitis were compared with MRI after 12 months of anti-tumour necrosis factor treatment. Intraobserver reproducibility was calculated using intra-class correlation coefficient.
Results: Interobserver reliability was 'good' for detection of erosions (κ = 0.70), BME (κ = 0.77) and synovitis (κ = 0.77), but 'poor' for osteophytes (κ = 0.12). Post-treatment DCE-MRI showed decreasing maximum upslope (p = 0.002) and absolute (p = 0.002) and relative (p = 0.01) enhancement compared to the initial scan. Intraobserver reproducibility of DCE-MRI was 'almost perfect' or 'strong' for all parameters.
Conclusions: 3 T DCE-MRI demonstrates changes in time intensity curves of synovitis in EOA of the interphalangeal joints in a longitudinal study, indicating this technique is promising for monitoring therapy response.