[Transient heterogeneous enhancement on dual-phase helical CT of liver]

Transient heterogeneous enhancement was seen on the arterial phase of dual phase helical CT of the liver. The shape of the enhancement was appeared wedged or patchy. These phenomena without liver tumor were observed in 23 (2.3%) of 1012 patients with suspected hepatobiliary disease. Plain CT showed no attenuation difference in the liver. Twenty-two of these 23 cases were diagnosed as scarred liver, A-P shunt caused by liver biopsy, acute cholecystitis, liver abscess, liver cirrhosis, or advanced pancreas head cancer. The diagnosis of one case was uncertain. These phenomena were thought to be caused by 1) a regional direct increase in hepatic arterial flow due to arterial-portal (A-P) shunt, or hypervascular tumor ; or 2) a compensatory increase in hepatic arterial flow as a result of decreased portal venous flow caused by tumor invasion or severe liver cirrhosis.