The value of CT portography in diagnosis of cancer embolus

Objective: To evaluate the characteristics of vein cancer embolus on helical CT portography(CTP).Methods: The pre-and post contrast helical CT scans were performed in 30 cases,multiplanar reformation(MPR) and additional CTP were done in all the cases.After the therapy,12 patients were followed up by the use of CT.Results: 18 cases(60%) vein cancer embolus showed inhomogeneous hyper attenuation at arterial phase.25 cases(83%) were well demonstrated at portal venous phase and the main CT feature was strip filling defect.The feature was poorly displayed at the balance phase,and only the portal venous was displayed enlarge.So the portal vein cancer embolus could be clearly demonstrated on CTP images at portal venous phase.The direct CT features of the portal vein cancer embolus were the enlarged portal vein and intraluminal hyperdensity or filling defect.The indirect findings included enhancement of vessel wall(33%),demonstration of collateral circulation formation(43%),cavernous transformation of the portal vein(40%) and hemodynamic changes in the peripheral circulation.CT was no more clear than MPR in the two cases.Between that,SSD CTP was dimentionaly clear,but small cancer embolus was displayed poorly but it would be perfect in combination with MIP CTP.Conclution: Helical CT portography(CTP) can provide the comprehensive information about the portal vein cancer embolus.