Portal Venous-Phase CT of the Liver in Patients without Chronic Liver Damage: Does Portal-Inflow Tracking Improve Enhancement and Image Quality?

Abstract

Purpose: This study was undertaken to determine if portal-inflow bolus tracking outperforms aortic bolus tracking with respect to the image quality of contrast-enhanced portal venous-phase CT of the liver in patients without chronic liver damage. Materials and Methods: Contrast-enhanced CT of the liver was performed in 132 consecutive patients without chronic liver damage. Patients were prospectively assigned to three protocols: Protocol A-a portal venous-phase scan delay of 6 seconds after superior mesenteric venous (SMV) enhancement increased by 70 HU or 14 seconds after SMV enhancement was visually confirmed, and Protocols B and C-40 and 50 seconds, respectively, after abdominal aortic enhancement increased by 100 HU. Enhancement (HU) of abdominal aorta, portal trunk, and liver parenchyma and diagnostic acceptability were assessed. Results: HU of aorta was higher for protocol A than for protocols B and C (P < 0.05), whereas HU of portal trunk was higher for protocol B than for protocols A and C (P < 0.05). HUs of liver were similar in three protocols. No difference was found between diagnostic acceptabilities of three protocols. Conclusion: Portal-inflow bolus tracking did not outperform aortic tracking in terms of optimization of portal venous-phase CT in patients without chronic liver damage.