Development of a prognostic MRCP-score (DiStrict) for individuals with large-duct primary sclerosing cholangitis

BACKGROUND & AIMS: Magnetic resonance cholangiopancreatography (MRCP) is used for the diagnosis and follow-up of individuals with primary sclerosing cholangitis (PSC). The aim of our study is to develop an MRCP-score based on cholangiographic findings previously associated with outcomes and assess its reproducibility and prognostic value in PSC. METHODS: The score (DiStrict score) was developed based on the extent and severity of cholangiographic changes of intrahepatic and extrahepatic bile ducts (range 0–8) on 3D-MRCP. In this retrospective, multicentre study, three pairs of radiologists with different levels of expertise from three tertiary centres applied the score independently. MRCP examinations of 220 consecutive individuals with PSC from a prospectively collected PSC-cohort, with median follow-up of 7.4 years, were reviewed. Inter-reader and intrareader agreements were assessed via intraclass correlation coefficient (ICC). After consensus, the prognostic value of the score was assessed using Cox-regression and outcome-free survival rates were assessed via Kaplan-Meier estimates. Harrell's C-statistic was calculated. RESULTS: Forty patients developed outcomes (liver transplantation or liver-related death). Inter-reader agreement between experienced radiologists was good (ICC 0.82; 95% CI 0.74–0.87, and ICC 0.81; 95% CI 0.70–0.87, respectively) and better than the agreement for the pair of experienced/less-experienced radiologists (ICC 0.48; 95% CI 0.05–0.72). Agreement between radiologists from the three centres was good (ICC 0.76; 95% CI 0.57–0.89). Intrareader agreement was good to excellent (ICC 0.85–0.93). Harrell's C was 0.78. Patients with a DiStrict score of 5–8 had 8.2-fold higher risk (hazard ratio 8.2; 95% CI 2.97–22.65) of developing outcomes, and significantly worse survival (p <0.001), compared to those with a DiStrict score of 1–4. CONCLUSIONS: The novel DiStrict score is reproducible and strongly associated with outcomes, indicating its prognostic value for individuals with PSC in ...