title: Peripheral cholangiocarcinoma of the liver: two-phase spiral CT findings.
abstract: OBJECTIVE
  To determine characteristic features of peripheral cholangiocarcinoma on two-phase spiral computed tomographic (CT) scans.
  
  
  METHODS
  Thirty-four patients with peripheral cholangiocarcinoma underwent two-phase spiral CT. Hepatic arterial phase and portal venous phase images were obtained 30 and 65 seconds, respectively, after the start of contrast material infusion.
  
  
  RESULTS
  Thin, mild, incomplete rimlike contrast enhancement at the tumor periphery was seen on CT scans from both phases in 23 patients. Thick, continuous rimlike contrast enhancement and marked homogeneous contrast enhancement were present on scans in four patients and one patient, respectively. No definite contrast enhancement pattern was seen on scans in six patients. Other findings included increased lobar or segmental hepatic attenuation in adjacent normal liver during the arterial phase (n = 10), markedly low attenuation with amorphous areas of slightly high attenuation in the tumor during both phases (n = 33), internal septumlike linear structures (n = 8), narrowing or obstruction of the portal vein as it traversed the tumor (n = 16), and a patent hepatic vein (n = 4).
  
  
  CONCLUSIONS
  Thin, mild, incomplete rimlike contrast enhancement at the tumor periphery and markedly low intratumoral attenuation with amorphous areas of slightly high attenuation during both scanning phases are typical findings of peripheral cholangiocarcinoma.
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Chongno-gu, Korea.
authors.forename: T K
authors.initials: TK
authors.lastname: Kim
authors.forename: B I
authors.initials: BI
authors.lastname: Choi
authors.forename: J K
authors.initials: JK
authors.lastname: Han
authors.forename: H J
authors.initials: HJ
authors.lastname: Jang
authors.forename: S G
authors.initials: SG
authors.lastname: Cho
authors.forename: M C
authors.initials: MC
authors.lastname: Han
mesh_terms: D001650:Bile Duct Neoplasms / Q000000981:diagnostic imaging*; D001653:Bile Ducts, Intrahepatic / Q000000981:diagnostic imaging*; D018281:Cholangiocarcinoma / Q000000981:diagnostic imaging*; D003287:Contrast Media; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007483:Iothalamic Acid / Q000031:analogs & derivatives; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007483:Iothalamic Acid; C019462:meglumine ioglicinate