Measurement of the contrast values for the hepatic vessels and hepatic parenchyma on a representative image obtained 50 s after injection for the anesthesia protocol. The contrast values of the aorta (AO), caudal vena cava (CVC), portal vein (PV), and hepatic parenchyma (HP) were measured by placing the region of interest (ROI) in the center of the AO, center of the CVC, the center of the PV, and right lateral lobar parenchyma, respectively. ROIs demarcated by red lines have an area of 40 mm2 and those in blue have an area of 200 mm2.