Background & aimsQuantitative magnetic resonance cholangiopancreatography (MRCP) metrics showed prognostic potential in primary sclerosing cholangitis (PSC). This international multi-centre study aimed to provide the first reference range for quantitative metrics in PSC and assess the additional role of quantitative metrics in prognostication.MethodsQuantified MRCP (MRCP+) and clinical data were collected from six European tertiary referral and transplantation centres. A healthy cohort was available for comparison. Least Absolute Shrinkage and Selection Operator analysis was used to derive variables for a prognostic model in a derivation cohort, referred to as quantitative MRCP augmented Amsterdam Oxford Model (qmAOM). Composite endpoint included PSC-related mortality, transplantation, or hepatic decompensation, without hepatic decompensation as secondary endpoint. Performance was assessed in the validation cohort, expressed as C-statistic [95% CI], and compared with the Amsterdam Oxford Model (AOM), Mayo Risk and MRCP+, bilirubin and aspartate aminotransferase (M+BA) scores.ResultsIn total, 457 participants with PSC were included for the reference range, which differed significantly in comparison to the healthy controls. Prognostic analysis included 320 participants. qmAOM included: age at PSC diagnosis, IBD presence, serum alkaline phosphatase, aspartate aminotransferase, albumin, bilirubin, platelets, number of strictures, number of ducts with strictures or dilatations and proportion of 3-5mm ducts. qmAOM, AOM and M+BA demonstrated 0.83 [0.77-0.93], 0.79 [0.68-0.91] and 0.65 [0.64-0.84], respectively. In secondary endpoint analysis, qmAOM and Mayo Risk Score demonstrated 0.84 [0.76-0.86] and 0.74 [0.68-0.81], respectively. In bootstrap analysis using the entire prognostic cohort, qmAOM performed significantly better than AOM and M+BA (0.82; 0.75; 0.70, respectively; p < 0.001) CONCLUSIONS: This study provides the first reference range of quantitative metrics in PSC and indicates that quantitative biliary metrics improve discriminative performance in event-free survival in PSC.Impact and implicationsThis study establishes a reference range for quantitative MRCP metrics in primary sclerosing cholangitis and demonstrates their additive value predicting event-free survival. These findings support the incorporation of multi-domain approaches in prognostic modelling and potential of quantitative imaging as surrogate endpoint in clinical trials.