Navigator-triggered isotropic three-dimensional magnetic resonance cholangiopancreatography in the diagnosis of malignant biliary obstructions: comparison with direct cholangiography.

PURPOSE: To compare the diagnostic accuracy of navigator-triggered isotropic three-dimensional (3D) MR cholangiopancreatography (MRCP) using parallel imaging for malignant biliary obstruction with direct cholangiography.

MATERIALS AND METHODS: A total of 23 patients with malignant biliary obstruction underwent MRCP and endoscopic retrograde cholangiopancreatography (ERCP)/percutaneous transhepatic cholangiography (PTC). Two observers retrospectively evaluated 3D-MRCP and ERCP/PTC and recorded the level of obstruction and extent of tumor along with their confidence. The quality of images and morphologic appearance of stricture were also evaluated by two reviewers. The results of MRCP and ERCP/PTC were compared with surgical and histopathological data.

RESULTS: 3D-MRCP was of diagnostic quality and free of artifacts in all patients, whereas ERCP/PTC examinations failed in three patients. For the evaluation of level of obstruction, there was no statistical significance between 3D-MRCP and ERCP/PTC. 3D-MRCP was superior to ERCP/PTC in the assessment of anatomical extent of hilar bile duct involvement, but did not show statistical significance. The accuracy of 3D-MRCP in determining tumoral extent of hilar cancer was higher than that of ERCP/PTC, but it was not statistically significant. The image quality of 3D-MRCP was superior to ERCP/PTC. There was good agreement between morphologic appearance at MRCP and those at ERCP/PTC.

CONCLUSION: 3D-MRCP can accurately assess the level of obstruction and extent of tumor in patients with malignant biliary obstruction.