Stepwise evaluation of liver sectors and liver segments by endoscopic ultrasound

Figure 14 Hepatic veins dividing liver segments. A: Image showing left lobe segments; B: The upper and lower tributaries of the hepatic vein indicate the upper and lower segments of the left lateral and left medial sectors. Segments II, III, IVa, and IVb veins are seen. In this case, the imaging is done from the visceral surface of the liver and from an area close to the antrum and body. Hence, segment IV appears closer to the probe than segment III. It must be clear that while imaging from the lower end of the esophagus that the left lateral segment is closer while during imaging from the visceral surface of the liver that the orientation of a segment may vary depending on the location of probe (for example, near the antrum segment IV is closer than segment III, and near the fundus and proximal body segment III is closer than segment IV). The white line is an extrapolated line that has been drawn in an approximate axis from the upper part of the umbilical part of the left branch of the portal vein; C: A line going through the middle hepatic vein separates the left medial and right anterior sectors; D: A line along the upper part of the transverse fissure (along the upper edge of the portal vein) subdivides the upper and lower segments of the left medial (segments IVa and IVb) and right anterior (segments VIII and V) segments. MHV: Middle hepatic vein; IVC: Inferior vena cava; PV: Portal vein.