Slow-injection CT scanning for the detection of vascular invasion in biliary cancers

Preoperative diagnosis of vascular invasion is important to improve the operative planning. We performed ''Slow-injection dynamic CT scanning (SI-CT)'' and compared it with conventional angiography to evaluate the detecting of vascular invasion in biliary cancers. In SI-CT, the relationships between tumors and vessels were classified into four types. We hypothesized that Type I · II had not been invaded and Type III · IV had been invaded. The diagnostic accuracy of SI-CT was 91.1 % in common hepatic artery (CHA), 82.1 % in proper and right/left heaptic artery (PHA), and 87.5 % in portal vein (PV). On the other hand, that of angiography was 94.6 % in CHA, 85.7 % in PHA, and 85.7 % in PV. So, the accuracy of SI-CT in detecting vascular invasion by biliary cancers was comparable to that of angiography. The major advantage of SI-CT is the visualization not only the vessels, but also the tumors and surrounding organs. The resectability of cases with portal vein invasion varied according to the CT type; Type III lesion were often resectable whereas Type IV lesion were generally unresectable. (author)