title: Angiographic assessment of the right hepatic artery for encasement by hilar cholangiocarcinoma: comparison between antero-posterior and right anterior oblique projections.
abstract: OBJECTIVE
  To evaluate the usefulness of right anterior oblique (RAO) arteriography for evaluating encasement of the right hepatic artery (RHA) by hilar cholangiocarcinoma.
  
  
  METHODS
  Celiac arteriography was performed in both the antero-posterior (AP) and RAO projection in ten patients with cholangiocarcinoma. The lengths of the arteries between the bifurcation of the anterior and posterior branch of the liver and the following points were measured: (a) the bifurcation of the left and right hepatic artery (AP-LR), (b) the bifurcation of the proper hepatic artery and the gastroduodenal artery (AP-PG). Additionally, image quality in investigating the invasion of the RHA was evaluated.
  
  
  RESULTS
  On the AP images, the average lengths of AP-LR and AP-PG were 24.5 +/- 5.1 mm and 30.0 +/- 4.9 mm, respectively. On RAO images, the lengths were 28.2 +/- 4.6 mm and 32.7 +/- 4.8 mm, respectively. Every length was different between the two projections (p < 0.01). In 6 of 10 patients with hilar cholangiocarcinoma, images in RAO projections were superior to AP images for evaluation of encasement.
  
  
  CONCLUSIONS
  We conclude that angiography obtained in the RAO projection yields images that are superior to those obtained in the conventional AP projection for assessment of RHA encasement.
authors.affiliation: Department of the Diagnostic Radiology, National Cancer Center Hospital, 5-1-1, Tsukiji, Chuo-ku, Tokyo 104, Japan. hsfuruka@gan2.ncc.go.jp
authors.forename: H
authors.initials: H
authors.lastname: Furukawa
authors.forename: R
authors.initials: R
authors.lastname: Iwata
authors.forename: N
authors.initials: N
authors.lastname: Moriyama
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018281:Cholangiocarcinoma / Q000000981:diagnostic imaging*; D005260:Female; D006499:Hepatic Artery / Q000000981:diagnostic imaging*; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D011859:Radiography