Etiology of biliary stenosis at MR Cholangiography: correlation with pathology findings

OBJECTIVE: To evaluate the accuracy of MR cholangiography to differentiate between the benign and malignant etiology of biliary strictures, excluding bilioenteric anastomoses. MATERIALS AND METHODS: 49 patients (26 males, 23 females) with suspected biliary stricture underwent MR cholangiography at 1.5T (Siemens Symphony). RARE and HASTE sequences were acquired in the coronal, oblique and axial planes. MR cholangiography findings were reviewed by two independent radiologists and correlated with the final histological diagnosis. Sensitivity, specificity, and agreement were calculated with a 95% confidence interval. RESULTS: Benign stenosis was identified in 23 patients (47%) and malignant stenosis in 26 (53%). The sensitivity of MR cholangiography was 64% and the specificity was 96%. The agreement between results at MR cholangiography and histology was moderate. The inter-observer agreement for MR cholangiography was good with a Kappa value of 0.61. CONCLUSION: MR cholangiography has the potential to replace diagnostic cholangiography in patients with suspected biliary stricture. Direct cholangiography could be reserved for patients where a therapeutic procedure is anticipated.