title: Distinguishing intrahepatic cholangiocarcinoma from poorly differentiated hepatocellular carcinoma using precontrast and gadoxetic acid-enhanced MRI.
abstract: OBJECTIVE
  We aimed to gain further insight in magnetic resonance imaging characteristics of mass-forming intrahepatic cholangiocarcinoma (mICC), its enhancement pattern with gadoxetic acid contrast agent, and distinction from poorly differentiated hepatocellular carcinoma (pHCC).
  
  
  METHODS
  Fourteen mICC and 22 pHCC nodules were included in this study. Two observers recorded the tumor shape, intratumoral hemorrhage, fat on chemical shift imaging, signal intensity at the center of the tumor on T2-weighted image, fibrous capsule, enhancement pattern on arterial phase of dynamic study, late enhancement three minutes after contrast injection (dynamic late phase), contrast uptake on hepatobiliary phase, apparent diffusion coefficient, vascular invasion, and intrahepatic metastasis.
  
  
  RESULTS
  Late enhancement was more common in mICC (n=10, 71%) than in pHCC (n=3, 14%) (P < 0.001). A fat component was observed in 11 pHCC cases (50%) versus none of mICC cases (P = 0.002). Fibrous capsule was observed in 13 pHCC cases (59%) versus none of mICC cases (P < 0.001). On T2-weighted images a hypointense area was seen at the center of the tumor in 43% of mICC (6/14) and 9% of pHCC (2/22) cases (P = 0.018). Other parameters were not significantly different between the two types of nodules.
  
  
  CONCLUSIONS
  The absence of fat and fibrous capsule, and presence of enhancement at three minutes appear to be most characteristic for mICC and may help its differentiation from pHCC.
authors.affiliation: Department of Radiology, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan. asayama@radiol.med.kyushu-u.ac.jp.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Asayama
authors.forename: Akihiro
authors.initials: A
authors.lastname: Nishie
authors.forename: Kousei
authors.initials: K
authors.lastname: Ishigami
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Ushijima
authors.forename: Yukihisa
authors.initials: Y
authors.lastname: Takayama
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Fujita
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Kubo
authors.forename: Shinichi
authors.initials: S
authors.lastname: Aishima
authors.forename: Ken
authors.initials: K
authors.lastname: Shirabe
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshiura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Honda
mesh_terms: D000368:Aged; D001650:Bile Duct Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging*; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis / Q000000981:diagnostic imaging*; D018281:Cholangiocarcinoma / Q000175:diagnosis / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005260:Female; D019786:Gadolinium DTPA / Q000032:analysis; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008113:Liver Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged
chemical_list: C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA