Magnetic resonance cholangiography compared with endoscopic retrograde cholangiography in the diagnosis of primary sclerosing cholangitis

Magnetic resonance cholangiography (MRC) has gained popularity for diagnosing primary sclerosing cholangitis (PSC). We determined the accuracy of MRC compared with endoscopic retrograde cholangiography (ERC) for diagnosing PSC. This retrospective case-control study was conducted on patients referred to an outpatient gastroenterology clinic from 2001 to 2013. Patients with established diagnosis of PSC who had undergone MRC and ERC within a 6-month interval were included. Controls were selected from patients who had undergone imaging for reasons other than PSC evaluation. Disease outcome at the study time and liver biochemistry data at diagnosis and 1-year thereafter were retrieved. Diagnostic accuracy of MRC in comparison with ERC was evaluated. A total of 46 definite PSC patients (age at diagnosis = 36.8 ± 11.6 years, 33 male) were found. Diagnostic imaging for PSC was ERC alone in 12, MRC alone in 23, and ERC plus MRC in 11 patients. Controls were 89 patients mostly with bile stones. The sensitivity, specificity, and positive and negative likelihood ratios of MRC was 90.9%, 95.5%,20.23, and 0.10, respectively. Early PSC was found more frequently by MRC compared with ERC (30.4% vs. 8.3%, P = 0.146). No significant difference was found between imaging modalities with regards to patients’ outcome (P = 0.786) or liver biochemistry at diagnosis or 1-year thereafter (P >0.05). Starting diagnostic imaging for PSC with MRC seems better and may provide diagnosis of PSC at its earlier phase. Further studies with larger sample of patients and longer follow-ups are warranted.