Breathhold unenhanced and gadolinium-enhanced magnetic resonance tomography and magnetic resonance cholangiography in hilar cholangiocarcinoma.

We assessed the imaging characteristics of hilar cholangiocarcinoma in magnetic resonance imaging (MRI) and magnetic resonance cholangiography (MRC). Breathhold MRI (T2-weighted turbo spin echo sequences, unenhanced T1-weighted gradient echo sequences, and gadolinium-enhanced fat-suppressed gradient echo sequences) and breathhold MRC (fat-suppressed two-dimensional projection images) performed in 12 patients with histologically confirmed hilar cholangiocarcinoma were retrospectively reviewed for morphological tumor characteristics and contrast enhancement patterns. MRC demonstrated a significant bile duct stenosis with intrahepatic bile duct dilatation in all cases except in one patient who received an endoprothesis prior to imaging. Hilar cholangiocarcinoma was diagnosed by MRC only in one patient and MRI and MRC in 11. Mass lesions were seen in nine patients and circumferential tumor growth in three, including the patient diagnosed by MRC only. The tumor appeared hypointense relative to liver parenchyma in 10 of 11 patients in unenhanced T1-weighted images. T2-weighted sequences showed isointense or only slightly hyperintense signal in 5 of 11 patients, 3 of whom demonstrated desmoplastic reactions by histology. The other 6 patients revealed strongly hyperintense signal intensities. Contrast enhancement was increased compared to liver in 5 of 11 patients and decreased in 6 of 11 patients. MRI with MRC seem to be a sensitive tools in the detection of hilar cholangiocarcinomas. The variable imaging characteristics are most probably related to the inhomogeneous histological appearance of this tumor entity.