Figure 2a. Application of ROIs. (a) On coronal US image, two ROIs of 1 x 1 cm are located on hepatic parenchyma (left ROI) and renal cortex (right ROI) so as not to contain large vessels or renal sinus within the ROI. ROIs were selected along the focusing area, ensuring similar distances from the probe, and near the center line of the image to avoid distorting effects in ultrasonic wave patterns. (b) On transverse image, ROI of 2 x 2 cm was applied to fully include portal vein branch of segment VIII and adjacent structures.