title: Helical CT demonstration of dilated right inferior phrenic arteries as extrahepatic collateral arteries of hepatocellular carcinomas.
abstract: OBJECTIVE
  The purpose of this work was to demonstrate the appearance of the right inferior phrenic artery (RIPA) on CT in patients with hepatocellular carcinoma (HCC).
  
  
  METHODS
  We assessed the biphasic helical CT scans using 10 mm collimation in 16 patients with arteriographically proven HCCs supplied by the RIPAs. Size of the right and left inferior phrenic arteries and origin of the RIPA were evaluated and correlated with arteriographic images.
  
  
  RESULTS
  Helical CT showed dilated RIPAs on the right diaphragmatic crus as foci of high attenuation on arterial-phase images in all patients. Diameter of the RIPA (average 3.3 mm) was larger than that of the left inferior phrenic artery (average 1.5 mm). The origin of the RIPAs was correctly predicted in 13 of 16 (celiac artery 6, abdominal aorta 5, right renal artery 2) patients.
  
  
  CONCLUSIONS
  Asymmetric dilatation of the RIPA as an indicator of extrahepatic collateral of HCC can be demonstrated on the right diaphragmatic crus with arteriographic images of biphasic helical CT.
authors.affiliation: Department of Radiology, Showa University School of Medicine, Tokyo, Japan. gokan@med.showa-u.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Gokan
authors.forename: T
authors.initials: T
authors.lastname: Hashimoto
authors.forename: S
authors.initials: S
authors.lastname: Matsui
authors.forename: T
authors.initials: T
authors.lastname: Kushihashi
authors.forename: H
authors.initials: H
authors.lastname: Nobusawa
authors.forename: H
authors.initials: H
authors.lastname: Munechika
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001158:Arteries / Q000473:pathology*; D006528:Carcinoma, Hepatocellular / Q000098:blood supply / Q000175:diagnosis / Q000000981:diagnostic imaging*; D003097:Collateral Circulation; D004106:Dilatation; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000098:blood supply / Q000175:diagnosis / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D014057:Tomography, X-Ray Computed / Q000379:methods