title: Typical and atypical imaging findings of intrahepatic cholangiocarcinoma using gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging.
abstract: OBJECTIVE
  The objective of this study was to examine the imaging features of classic mass-forming intrahepatic cholangiocarcinoma (MICC) and nonclassic hypervascular MICC on gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging.
  
  
  METHODS
  Twenty pathologically confirmed MICCs were included. Two radiologists retrospectively reviewed the imaging characteristics on T2-weighted imaging, diffusion-weighted imaging, dynamic contrast-enhanced images, and hepatobiliary phase (HBP) of each MICC. For the morphologic feature of defect, HBP signal intensity (SI) ratio was calculated by dividing the SI of the MICC by nearby normal liver parenchyma SI.
  
  
  RESULTS
  Classic MICCs (n = 14) showed classic rim or peripheral enhancement at arterial dominant phase with centripetal enhance in the delayed phases. Hypervascular MICCs (n = 6) showed complete (n = 4) or near-complete (n = 2) arterial enhancement and washout (n = 6) on delayed phases. On HBP, 13 classic MICCs (93%) and 2 hypervascular MICCs (33%) showed cloud-like SI in the center ("EOB cloud") with peripheral defect. Mean SI ratio was 0.77 in classic MICCs and 0.59 in hypervascular MICC (P = 0.057).
  
  
  CONCLUSIONS
  Classic MICCs (70%) frequently showed progressive centripetal enhancement on dynamic phase, and central EOB-cloud appearance with distinct peripheral defect on HBP. Nonclassic hypervascular MICCs comprised 30% of the MICCs in this study. Compared with classic MICCs, hypervascular MICCs showed wash-in on arterial dominant phase and washout on delayed phase.
authors.affiliation: Department of Radiology, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea.
authors.forename: So Hee
authors.initials: SH
authors.lastname: Kim
authors.forename: Chang Hee
authors.initials: CH
authors.lastname: Lee
authors.forename: Baek Hui
authors.initials: BH
authors.lastname: Kim
authors.forename: Wan Bae
authors.initials: WB
authors.lastname: Kim
authors.forename: Suk Keu
authors.initials: SK
authors.lastname: Yeom
authors.forename: Kyeong Ah
authors.initials: KA
authors.lastname: Kim
authors.forename: Cheol Min
authors.initials: CM
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms; D001653:Bile Ducts, Intrahepatic; D018281:Cholangiocarcinoma / Q000175:diagnosis*; D003287:Contrast Media; D003937:Diagnosis, Differential; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008099:Liver / Q000473:pathology*; D008113:Liver Neoplasms / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012189:Retrospective Studies
chemical_list: D003287:Contrast Media; C073590:gadolinium ethoxybenzyl DTPA; D019786:Gadolinium DTPA