Detection and characterization of hepatocellular carcinoma: value of dynamic CT during the arterial dominant phase with uniphasic contrast medium injection.

Abstract

Our goal was to assess the effect of dynamic CT during the arterial dominant phase with uniphasic injection of intravenous contrast material (5 ml/s) in the detection and characterization of hepatocellular carcinomas (HCCs). Three-phase incremental dynamic CT was performed in 66 patients with 84 HCCs diagnosed by pathologic findings, characteristic angiographic findings, and clinical manifestations. One hundred fifty milliliters of nonionic contrast medium was administered intravenously by using a power injector at a flow rate of 5 ml/s for 30 s, and three-phase images were obtained at 20-45 s (arterial dominant phase), 55-80 s (portal venous phase), and 2-4 min (equilibrium phase) after the start of uniphasic intravenous injection. Three-phase images in 66 patients were compared and assessed for the detectability and enhancement pattern of the tumors. The arterial dominant phase images of dynamic CT showed a moderate to marked hyperattenuation in 73 (87%) of the 84 HCCs, isoattenuation in 6 (7%), and hypoattenuation in 5 (6%). The portal venous phase images showed hyperattenuation in 6 (7%), isoattenuation in 45 (54%), and hypoattenuation in 33 (39%). In the equilibrium phase, CT findings showed hypoattenuation in 67 (80%) and isoattenuation in 17 (20%). The detectability of HCCs in the arterial dominant, portal venous, and equilibrium phase was 93, 46, and 80%, respectively. The detectability of HCCs in the arterial dominant phase was significantly (p < 0.0001) superior to that in both the portal venous phase and the equilibrium phase. Dynamic CT during the arterial dominant phase with uniphasic injection of intravenous contrast medium (5 ml/s) is a useful method in the detection and characterization of HCCs.