title: Portal venous and segmental anatomy of the right hemiliver: observations based on three-dimensional spiral CT renderings.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the segmental anatomy of the right hemiliver and to assess whether the right hepatic vein and right portal trunk are accurate indicators of the position of the right and transverse scissurae, respectively.
  
  
  METHODS
  We examined 26 patients with spiral CT using 5-mm slices, reconstructed at 2-mm intervals. Three-dimensional renderings of the portal and hepatic venous structures were created. The portal ramification pattern and relationship between the hepatic veins and portal system were evaluated.
  
  
  RESULTS
  In the right hemiliver, an anterosuperior sector and a posteroinferior sector were present in all patients. In addition, in nine patients, a total of 15 accessory portal sectors were present, each arising directly from the portal bifurcation or the right portal trunk. Further subdivision of the portal sectors showed marked individual variability, with no prevailing branching pattern. The scissura between the anterosuperior and posteroinferior sectors showed an angled orientation--its cranial part was tilted posteriorly (average, 58.4 degrees) and its caudal part was tilted anteriorly (average, 2.8 degrees)--relative to the coronal plane. In 24 patients, portal branches crossed the plane of the right hepatic vein. No transverse scissura could be seen in the anterosuperior or posteroinferior sector.
  
  
  CONCLUSIONS
  The right hemiliver could be divided into anterosuperior and posteroinferior sectors in all patients studied. Many patients have accessory sectors. Further subdivision into portal segments can be described only after the individual portal branching pattern has been studied. The right hepatic vein is an inaccurate indicator of the position of the right scissura. No clear transverse scissura can be seen in the right hemiliver.
authors.affiliation: Department of Radiology, University Hospital Utrecht, The Netherlands.
authors.forename: M S
authors.initials: MS
authors.lastname: van Leeuwen
authors.forename: J
authors.initials: J
authors.lastname: Noordzij
authors.forename: M A
authors.initials: MA
authors.lastname: Fernandez
authors.forename: A
authors.initials: A
authors.lastname: Hennipman
authors.forename: M A
authors.initials: MA
authors.lastname: Feldberg
authors.forename: E H
authors.initials: EH
authors.lastname: Dillon
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006503:Hepatic Veins / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008099:Liver / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011169:Portal Vein / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed