Preoperative Evaluation of Malignant Perihilar Biliary Obstruction: Negative-Contrast CT Cholangiopancreatography and CT Angiography Versus MRCP and MR Angiography.

Objective: The purpose of this study was to compare negative-contrast CT cholangiopancreatography (CTCP) and CT angiography (CTA) with MRCP and MR angiography (MRA) for the preoperative evaluation of malignant perihilar biliary obstruction.

Materials And Methods: Twenty-one patients with pathologically proven malignant perihilar biliary obstructions who had undergone both CT and MRI examinations were reviewed retrospectively. Two reviewers independently analyzed the two image sets-the negative-contrast CTCP and CTA images (i.e., CT set) and the MRCP and MRA images (i.e., MRI set)-in preoperatively evaluating the classification of malignant perihilar biliary obstruction, hepatic artery and portal vein invasion, nodal metastasis, and organ spread. The results were compared with surgical and pathologic records.

Results: For the classification of malignant perihilar biliary obstruction on the two image sets, the accuracy was not statistically significant (p = 1.000 for reviewer 1 and p = 0.500 for reviewer 2). For the evaluation of portal vein invasion, nodal metastasis, and organ spread, the accuracies were also not statistically significantly different (p = 0.335, 0.339, and 0.781 for reviewer 1; and p = 0.403, 0.495, and 0.325 for reviewer 2, respectively). In the assessment of hepatic artery status, the accuracy was statistically significant (p = 0.046 for reviewer 1 and p = 0.036 for reviewer 2).

Conclusion: Compared with the MRI set, the CT set provides equivalent performance in assessing the classification of malignant perihilar biliary obstruction, portal vein involvement, nodal metastasis, and organ spread, but has higher accuracy in assessing arterial invasion.