Validation of MRI radiological reports in pediatric MS according to the McDonald 2017 criteria: A Danish nationwide multicenter cohort study

•Agreement between MRI reports and secondary review ranged 68%–100% for MS outcomes.•Kappa values for MS outcomes ranged from 0.42 (“moderate”) to 1.00 (“excellent”).•Agreement was higher when MRI outcomes were present.•Kappa for fulfilling McDonald criteria was 0.60 (95% CI=0.36–0.84) at baseline.•Kappa for a new lesion on follow-up MRI was 0.41 (95% CI=0.11–0.70).