Liver segment S8 is the upper right anterior lobe of the liver. This segmentation belongs to the most commonly used Couinaud segmentation method in imaging, which is based on the anatomical relationship of the hepatic vessels to divide the liver into 8 segments: First, the liver is divided into left and right lobes longitudinally by the middle hepatic vein; then into anterior and posterior segments by the right hepatic vein; then into medial and lateral segments by the falciform ligament; and finally into upper and lower segments by following the trunks of the right and left portal veins horizontally in the first porta hepatis. Thus, the eight segments of the liver are: S1 is the caudate lobe, S2 is the upper segment of the left outer lobe, S3 is the lower segment of the left lower lobe, S4 is the left inner lobe, S5 is the lower segment of the right anterior lobe, S6 is the lower segment of the right posterior lobe, S7 is the upper segment of the right posterior lobe, and S8 is the upper segment of the right anterior lobe.