title: Radiological anatomy of the medial segmental bile duct of the liver assessed by CT cholangiography.
abstract: OBJECTIVE
  To analyze drainage areas and points of confluence of the medial segmental bile ducts of the liver, 72 patients with obstructive jaundice underwent computed tomography cholangiography.
  
  
  METHODS
  We divided the medial segmental ducts into the following three subsegmental branches: B4a was defined as the inferior branch, B4b as the superior branch, and B4c as the dorsal branch.
  
  
  RESULTS
  In 62 (86%) of the 72 patients, each B4a and B4b branches joined to form a single medial segmental duct, which joined the left hepatic duct in 25 patients (35%), the confluence of the lateral inferior (B3) and superior (B2) branches in 18 patients (25%), B3 in 15 patients (20%), the confluence of the right and left hepatic ducts in 4 patients (6%). In addition, these medial segmental ducts primarily entered the left hepatic duct in the final half of its length or more distant portion from the hepatic hilum in 43 (77%) of the 62 patients.
  
  
  CONCLUSIONS
  Thus, in most cases the inferior area of the medial segment should be preserved when right-sided resection of the liver is indicated for hilar bile duct cancer.
authors.affiliation: Department of Academic Surgery, Chiba University Graduate School of Medicine, 1-8-1 Inohana, Chuou-ku, Chiba 260-0856, Japan. cho@insei.m.chiba-u.ac.jp
authors.forename: Akihiro
authors.initials: A
authors.lastname: Cho
authors.forename: Munemasa
authors.initials: M
authors.lastname: Ryu
authors.forename: Taira
authors.initials: T
authors.lastname: Kinoshita
authors.forename: Noriaki
authors.initials: N
authors.lastname: Kawano
authors.forename: Masaru
authors.initials: M
authors.lastname: Konishi
authors.forename: Yukimasa
authors.initials: Y
authors.lastname: Miyazawa
authors.forename: Shinichi
authors.initials: S
authors.lastname: Okazumi
authors.forename: Takenori
authors.initials: T
authors.lastname: Ochiai
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001653:Bile Ducts, Intrahepatic / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D002758:Cholangiography; D002779:Cholestasis / Q000000981:diagnostic imaging / Q000209:etiology; D004067:Digestive System Neoplasms / Q000150:complications; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D036542:Tomography, Spiral Computed