Assess the reliability of early erosions in rheumatoid arthritis (EERA) software for quantifying erosive damage to the metacarpophalangeal joints of patients with rheumatoid arthritis (RA).
One hundred magnetic resonance image sets from 68 patients with early referral RA were evaluated. Reliability was assessed using 95% limits of agreement and intraclass correlation coefficient (ICC) with 95% CI.
Limits of agreement linearly depended on erosion volume: 0.44× between readers and 0.19× within readers. Interrater ICC was 0.976 (95% CI 0.965–0.984) and intrarater ICC was 0.996 (95% CI 0.994–0.997).
EERA is highly reproducible for quantifying erosions in patients with early RA.