MR imaging of peripheral cholangiocarcinoma.

A prospective study was performed to compare MR spin-echo (SE) sequences [repetition time/echo time (TR/TE) 2,000/80, 500/44 ms], unenhanced CT, and rapid intravenous contrast enhanced CT in eight consecutive patients with peripheral cholangiocarcinoma. All the tumors (ranging from 5 to 9.6 cm in size) were detected with all four techniques. Tumor contrast, however, was qualitatively greatest on long TR/TE SE images. With long TR/TE SE images, tumors were demonstrated as well-demarcated homogeneous regions of high signal intensity, and the anatomic relations between tumors and intrahepatic blood vessels were easily perceived. Detection of small intrahepatic metastatic foci was best on long TR/TE images. Tumor invasion of the portal vein's branches was also best seen on long TR/TE SE images. These results indicate that long TR/TE SE sequence is the most effective initial screening method in demonstrating the presence and determining resectability of peripheral cholangiocarcinoma.