Review
Copyright ©The Author(s) 2018.
World J Gastrointest Endosc. Nov 16, 2018; 10(11): 326-339
Published online Nov 16, 2018. doi: 10.4253/wjge.v10.i11.326
Table 1 The sectors and the segments of liver
Four hepatic sectorsEight hepatic segments
Segment I - the caudate lobe
Left lateral sectorSegment II - posterosuperior
Segment III - anteroinferior
Left medial sectorIVa - superior segment
IVb - inferior segment
Right anterior sectorSegment V - inferior segment
Segment VIII - superior segment
Right posterior sectorSegment VI - inferior segment
Segment VII - superior segment
Table 2 The home bases of imaging for liver segments
Home basesDefining of segments
Hepatic veinsLHV separates II and III from IV (a and b)
MHV separates IVa from VIII and IVb from V
RHV separates V from VI and VIII from VII
Portal vein and its branchesSuperior segments lie above and inferior segments lie below the transverse fissure
The LPV supplies segments II to IV
The RPV supplies segments V to VIII
IVCIVC passes through the bare area of the liver and is related to superior segments in the upper part, segment I for most of its course, and with segment VI close to the lower most part above the right kidney
IVC suprahepatic partA transverse plane defines the upper limit of superior segments (II, IV, VIII, and VII)
Ligamentum teresSeparates segment III from IVb
Ligamentum venosumSeparates I from IVa and II
GallbladderNeck lies close to segment V and fundus close to segment VI, from stomach IVb comes between the gallbladder and probe
Table 3 A difference in the segments of imaging from the three positions
StationCommentSegments visualized
Abdominal part of the esophagus and stomachProbe in the esophagus lies close to the left lobe of the liver and in the stomach close to the visceral surface of the liverSuperior segments and caudate lobe are in direct contact with the lower end of esophagus All segments except segment VIII on the visceral surface of liver are in contact with the stomach
Duodenal bulbProbe lies close to the hilum of the liverDirect contact with segment I and right lobe liver segments Left side segments are seen through caudate lobe, caudate process, and IVC
Second part of duodenum.Probe lies close to the hilum of the liverDirect contact with segment I and right lobe liver segments Left side segments are seen through caudate lobe, caudate process, and IVC
Table 4 The structures from three positions from station 1
Clockwise rotation from an open position to leftPart of portal veinPart of hepatic veinOther home base structuresMain sector of liver visualizedMain segments of liver visualizedFigure number for segment
Open position to leftPII and PIIILHVDiaphragm and heartLeft medial closer to left lateral1II, III, and IV2A, 2B, 3A, 5A
Neutral position after approximately 60° to 75° clockwise rotationFisheye appearance of LPVMHVLeft edge of transverse fissure attached to ligamentum venosum and ligamentum teresLeft medial closer to probe than right anteriorI and IV3A, 5B
Open position to right after further approximately 60° to 75° clockwise rotationRPV dividing into anterior and posterior branchesRHVRight edge of transverse fissure, IVC, gallbladder, and caudate processRight anterior closer to probe than right posteriorV, VI, VII, and VIII3A, 7A 7C, 7D
Table 5 The representation of liver segments
Home base structureCommentFigure No.
Hepatic veinsThe main left hepatic vein drains the two lateral segments of the left lobe (segments II and III)9D
The middle vein drains segment IV and the anterior sector of the right lobe (segments V and VIII)9B
The right vein drains the remainder of the right lobe (segments VI and VII) and a variable portion of segments Vand VIII9C
Hepatic vein tributariesThe higher tributary of LHV going towards the diaphragmatic and costal surface belongs to segment II9D
The higher tributary of MHV going towards the diaphragmatic and costal surface belongs to segment VIII9B, 14C, 14D
The higher tributary of RHV going towards the diaphragmatic and costal surface belongs to segment VII15A, 15C
The tributary of LHV going towards the liver hilum drains segment IVa14B
The tributary of MHV going towards the liver hilum drains segment IVb14D
The tributaries of RHV going towards the liver hilum drains segments Vand VIII9C
Right and left branches of the portal veinThe right branch of the portal vein supplies the right liver (segments Vto VIII)7A, 7B, 7C, 7D
The left branch of the portal vein supplies the left liver (segments II to IV)5A, 5B, 5C, 5D, 6A, 6B
The caudate lobe receives direct branches from both the right and left branches12C
Segmental branches of the portal veinThe extrahepatic part supplies segment I11D
The anterior branch of the RPV supplies segments Vand VIII7C
The posterior branch of the RPV supplies segments VI and VII7D
Right kidneyLies lateral to the infrahepatic part of the IVC8A
Caudate lobeForms an important anatomical landmark10A, 10B, 10D, 11A, 11B, 11C