title: Enhancement characteristics of cholangiocarcinomas on mutiphasic helical CT: emphasis on morphologic subtypes.
abstract: OBJECTIVE
  The purpose of this study was to characterize the differences in CT enhancement pattern among the morphologic subtypes of cholangiocarcinomas.
  
  
  METHODS
  Unenhanced, hepatic arterial (HAP), and portal venous phase (PVP) CT images of 84 patients with pathologically proven cholangiocarcinoma were retrospectively reviewed. Tumors were of the following types: 27 mass-forming, 39 periductal-infiltrating, and 18 intraductal. The CT attenuation values of tumors were measured at each phase. The tumor enhancement ratio (ER) on HAP and PVP was calculated.
  
  
  RESULTS
  Each cholangiocarcinoma subtype produced characteristic enhancement relative to liver on HAP and PVP images: mass-forming tumors demonstrated hyperenhancing periphery and hyopenhancing centers; periductal-infiltrating tumors, hyperenhancing; and intraductal tumors, hypoenhancing. The ER of the tumor types was significantly different (P<.001, HAP, PVP): periductal-infiltrating tumors showed the highest ER (2.5; 3.8); the centers of mass-forming tumors, lowest (1.5; 2.2); the peripheries of mass-forming tumors, high (2.1; 3.0); intraductal tumors, low (1.9; 2.6).
  
  
  CONCLUSIONS
  Cholangiocarcinoma subtypes tended to exhibit distinct enhancement characteristics. Knowledge of these enhancement patterns may aid diagnosis and surgical planning.
authors.affiliation: Department of Radiology, and Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Na Ra
authors.initials: NR
authors.lastname: Kim
authors.forename: Jeong Min
authors.initials: JM
authors.lastname: Lee
authors.forename: Se Hyung
authors.initials: SH
authors.lastname: Kim
authors.forename: Su Kyung
authors.initials: SK
authors.lastname: An
authors.forename: Chang Jin
authors.initials: CJ
authors.lastname: Han
authors.forename: Seung Hong
authors.initials: SH
authors.lastname: Choi
authors.forename: Joon Koo
authors.initials: JK
authors.lastname: Han
authors.forename: Hye Seung
authors.initials: HS
authors.lastname: Lee
authors.forename: Ja Jun
authors.initials: JJ
authors.lastname: Jang
authors.forename: Byung Ihn
authors.initials: BI
authors.lastname: Choi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D001653:Bile Ducts, Intrahepatic / Q000000981:diagnostic imaging / Q000473:pathology; D018281:Cholangiocarcinoma / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D036542:Tomography, Spiral Computed