Primary sclerosing cholangitis: meta-analysis of diagnostic performance of MR cholangiopancreatography.

Purpose: To determine the diagnostic accuracy of magnetic resonance cholangiopancreatography (MRCP) for detection of primary sclerosing cholangitis (PSC) in patients with biochemical cholestasis.
Materials and Methods: Two reviewers searched MEDLINE, EMBASE, and other electronic databases to identify prospective studies in which MRCP was evaluated and compared with endoscopic retrograde cholangiopancreatography (ERCP), clinical examination, and/or histologic analysis for diagnosis of PSC in cholestasis and control cases. Main study inclusion criteria were (a) use of ERCP or percutaneous transhepatic cholangiography (PTC) as part of the reference standard for the diagnosis of PSC, (b) inclusion of patients with hepatobiliary disease other than PSC (ie, nonhealthy control subjects), (c) blinding of MRCP image readers to reference-standard results, (d) prospective study with ERCP or MRCP performed after subject recruitment into the study, and (e) inclusion of raw data (for true-positive, false-positive, true-negative, and false-negative results) that could be found or calculated from the original study data. Major exclusion criteria were duplicate article (on a primary study) that contained all or some of the original study data and inclusion of fewer than 10 patients with PSC. Methodologic quality was assessed by using the Quality Assessment of Diagnostic Accuracy Studies tool. Bivariate random-effects meta-analytic methods were used to estimate summary, sensitivity, specificity, and receiver operating characteristic (ROC) curves.
Results: Six manuscripts with 456 subjects (with 623 independent readings)--185 with PSC--met the study inclusion criteria. The summary area under the ROC curve was 0.91. High heterogeneity (inconsistency index, 78%) was found but became moderate (inconsistency index, 36%) with the exclusion of one study in which the diagnostic threshold was set for high sensitivity. There was no evidence of publication bias (P = .27, bias coefficient analysis). Sensitivity and specificity of MRCP for PSC detection across all studies were 0.86 and 0.94, respectively. Positive and negative likelihood ratios with MRCP were 15.3 and 0.15, respectively. In patients with high pretest probabilities, MRCP enabled confirmation of PSC; in patients with low pretest probabilities, MRCP enabled exclusion of PSC. Worst-case-scenario (pretest probability, 50%) posttest probabilities were 94% and 13% for positive and negative MRCP results, respectively.
Conclusion: MRCP has high sensitivity and very high specificity for diagnosis of PSC. In many cases of suspected PSC, MRCP is sufficient for diagnosis, and, thus, the risks associated with ERCP can be avoided.