Intrahepatic cholangiocarcinoma: findings on spiral CT during arterial portography

To attempt to determine the characteristic imaging features of intrahepatic cholangiocarcinoma on spiral CT during arterial portography (CTAP), spiral CTAP examinations of 17 patients with pathologically confirmed intrahepatic cholangiocarcinoma were reviewed in consensus by three radiologists. The diameter of the tumors ranged from 1 to 12 cm (mean diameter, 6.6 cm). All tumors (100%) were hypoattenuating masses on spiral CTAP. In 11 cases, the tumor was homogeneous in attenuation (65%). Tumor margins were smooth and regular in 11 cases (65%). Vascular invasion was found in 14 cases (82%). Intrahepatic bile duct dilatation was present in seven cases (41%). This review shows that intrahepatic cholangiocarcinoma is associated with a constellation of findings on spiral CTAP. The presence of a low attenuation homogeneous intrahepatic mass with vascular invasion and intrahepatic bile duct dilatation on spiral CTAP images should raise the possibility of intrahepatic cholangiocarcinoma. However, these findings can be associated with other types of primary and secondary malignant hepatic tumors.