Dynamic helical biphasic CT emerges as a potential tool for the diagnosis of proximal arterioportal shunting.

BACKGROUND/AIMS: This article reports our preliminary observation regarding the diagnostic ability of dynamic helical biphasic computed tomography (CT) for proximal arterioportal shunting in hepatoma patients as compared with that of conventional angiography.

METHODOLOGY

Three hundred and sixty patients with clinically-suspected liver lesions received both dynamic helical biphasic CT scan and conventional angiography of the liver. The criteria for diagnosis of proximal arterioportal (AP) shunting in dynamic helical biphasic CT included early and strong enhancement of main portal vein or its major branches approaching the density of the aorta, or enhancement of the portal vein earlier than opacification of the splenic vein and superior mesenteric vein in the arterial phase. The angiographic diagnosis of proximal AP shunting was made if there was early opacification of the main portal vein or its major branches in the arterial phase. Peripheral subsegmental small AP shunting was excluded from our study. The existence and extent of AP shunting were compared in these two imaging modalities.

RESULTS

Dynamic helical biphasic CT scan demonstrated proximal AP shunting in 23 patients. All of these patients harbored hepatoma. Conventional angiography showed proximal AP shunting in 20 patients, which were all positive on dynamic helical CT. Dynamic helical biphasic CT demonstrated the presence of proximal AP shunting in 3 more patients than conventional angiography did. The extent of AP shunting was well correlated between these two imaging modalities in 17 patients.

CONCLUSIONS

From our preliminary experience, the diagnostic accuracy of dynamic helical biphasic CT for proximal AP shunting in patients with hepatoma seemed to be comparable to, or even surpassed that of conventional angiography. It seems that faint AP shunting in patients with large hepatoma might be missed by conventional angiography.