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

We assessed the imaging characteristics of hilar cholangiocarcinoma in magn etic resonance imaging (MRI) and magnetic resonance cholangiography (MRC). Breathhold MRI (T2-weighted turbo spin echo sequences, unenhanced T1-weight ed gradient echo sequences, and gadolinium-enhanced fat-suppressed gradient echo sequences) and breath-hold MRC (fat-suppressed two-dimensional projec tion images) performed in 12 patients with histologically confirmed hilar c holangiocarcinoma were retrospectively reviewed for morphological tumor cha racteristics and contrast enhancement patterns. MRC demonstrated a signific ant 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 MRT. and M RC in 11. Mass lesions were seen in nine patients and circumferential tumor growth in three, including the patient diagnosed by MRC only. The tumor ap peared hypointense relative to liver parenchyma in 10 of 11 patients in une nhanced T1-weighted images. T2-weighted sequences showed isointense or only slightly hyperintense signal in 5 of 11 patients, 3 of whom demonstrated d esmoplastic reactions by histology. The other 6 patients revealed strongly hyperintense signal intensities. Contrast enhancement was increased compare d 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 cholangiocarcino mas. The variable imaging characteristics are most probably related to the inhomogeneous histological appearance of this tumor entity.