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

Background and AimsMRCP is used for diagnosis and follow-up of patients with primary sclerosing cholangitis (PSC). Interest in the prognostic value of MRCP is increasing. 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.MethodsThe 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, ethics review board approved, multicentre study, three pairs of radiologists with different levels of expertise from three tertiary centres applied the score independently. MRCP- examinations of 220 consecutive PSC-patients from a prospectively collected PSC-cohort, with median follow-up of 7.4 years, were reviewed. Interreader 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.Results40 patients developed outcomes (liver transplantation or liver-related death). Interreader 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 radiologist (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 DiStrict-score of 5 – 8 had 8.2 times higher risk (HR=8.2; 95%CI:2.97–22.65) for developing outcomes, and significantly worse survival (P ConclusionsThe novel DiStrict-score is reproducible and strongly associated with outcomes, indicating its value for PSC-patient prognoses in clinical practice.Lay summaryDiagnosis of primary sclerosing cholangitis (PSC) is based on magnetic resonance cholangiopancreatography (MRCP). However, the role of MRCP in the prognosis of PSC is still unclear. We developed a novel, simple, and reproducible risk-score, based on MRCP findings, that showed a strong association with PSC patient prognoses (DiStrict score). This score can be easily used in clinical practice and thus has the potential to be useful in clinical trials and in patient counselling and management.