Reproducibility measurements

Two observers (SH and TT) conducted the examination to assess interobserver reproducibility. The intraobserver reproducibility of T2 value measurement, WORMS evaluation, MME distance, and osteophyte distance by MRI was as follows: interclass correlation coefficient (ICC) for interreader agreement 0.91 (95% CI 0.64–0.98) for T2 value, 0.94 (95% CI 0.91–0.96) for WORMS, 0.95 (95% CI 0.78–0.99) for MME, and 0.94 (95% CI 0.85–0.98) for osteophyte distance. Observers were blinded to any patient information during the evaluation process. The interobserver reproducibility was also high: ICC 0.91 (95% CI 0.63–0.97) for T2 value measurement, 0.90 (95% CI 0.86–0.93) for WORMS, 0.93 (95% CI 0.76–0.98) for MME, and 0.94 (95% CI 0.84–0.97) for osteophyte distance. The weighted kappa coefficients of inter- and intraobserver reliability for WORMS were 0.66 and 0.65, respectively.