Diagnostic yield of magnetic resonance imaging for cholangiocarcinoma in primary sclerosing cholangitis: A meta-analysis

Aim of the study: Combined magnetic resonance imaging and magnetic resonance cholangiopancreatography (MRI/MRCP) can identify biliary strictures and diagnose primary sclerosing cholangitis (PSC). Diagnosis of cholangiocarcinoma in patients with PSC remains challenging, and the accuracy of MRI/MRCP has not been completely established. We aimed to determine the sensitivity and specificity of MRI/MRCP in the diagnosis of cholangiocarcinoma among patients with PSC from the published literature. Material and methods: We searched Embase, PubMed, Cochrane, Scopus, ClinicalTrials.gov, and abstracts from relevant scientific meetings and performed a systematic review and meta-analysis to estimate the diagnostic yield of MRI/MRCP in patients with PSC. Sensitivity and specificity were calculated from pooled estimates of cholangiocarcinoma cases identified and lesions missed. Modifying variables were included in a meta-regression model. Results: Our literature search yielded 302 articles and 9 conference abstracts; 8 studies involving 846 liver patients from 5 countries were included in the final analysis. Of those, 531 had PSC and received MRI/MRCP. Thirty-six (6.8%) patients were diagnosed with cholangiocarcinoma (33 true positive, 3 false negative and 1 false positive). Pooled sensitivity was 98.9% (95% CI: 98.6-99.3%). Cholangiocarcinoma cases missed by MRI/MRCP were diagnosed as beading irregularities of the central hepatic ducts, or PSC-related diffuse stricture. Metaregression revealed that neither publication year, study design, nor sample size had a significant effect on observed cancer rates (p = 0.9, 0.3, and 0.3, respectively). Conclusions: MRI/MRCP followed by endoscopic retrograde cholangiopancreatography (ERCP) is a sensitive and specific tool to diagnose cholangiocarcinoma among patients with PSC. Further research should estimate MRI/ MRCP diagnostic accuracy for cholangiocarcinoma using prospective methodology and longer term outcomes.