title: CT features of an intraductal polypoid mass: Differentiation between hepatocellular carcinoma with bile duct tumor invasion and intraductal papillary cholangiocarcinoma.
abstract: OBJECTIVE
  To determine the CT features capable of differentiating hepatocellular carcinoma (HCC) with bile duct tumor invasion (BDTI) from intraductal cholangiocarcinoma (IDCC).
  
  
  METHODS
  Multiphasic CT images of 14 patients with HCC with BDTI and 18 patients with IDCC were retrospectively reviewed. Analysis of the CT findings included the size, location, and margin of the intraductal mass, the enhancement pattern of intraductal lesions, degree of ductal dilatation, presence of downstream ductal dilatation and ductal wall thickening, presence of parenchymal mass and its size, continuity of parenchymal mass with intraductal mass, and liver cirrhosis. Objective evaluation of the enhancement patterns of intraductal tumors was done by measuring the CT attenuation coefficients of the tumors and the uninvolved hepatic parenchyma in each phase. Among these findings, statistically significant variables were then determined using Fisher exact test or Mann-Whitney test.
  
  
  RESULTS
  Significant variables that helped differentiating HCC with BDTI from IDCC included the presence of parenchymal mass, liver cirrhosis, and the hyperattenuating intraductal tumor on the hepatic arterial phase (HAP). On unenhanced images, the tumor-to-liver contrast of IDCC (16.7 +/- 8.1) was greater than that of HCC with BDTI (6.4 +/- 10.4), but on HAP, that of HCC with BDTI (26.5 +/- 28.2) was greater than that of IDCC (5.9 +/- 18.7) (P < 0.05). In addition, there was a significant difference in the enhancement ratio of the intraductal tumors on portal venous phase (PVP) between the 2 conditions (P = 0.003).
  
  
  CONCLUSIONS
  Several objective and subjective multiphasic CT findings may help differentiating HCC with BDTI from IDCC.
authors.affiliation: Department of Radiology and Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Ah Young
authors.initials: AY
authors.lastname: Jung
authors.forename: Jeong Min
authors.initials: JM
authors.lastname: Lee
authors.forename: Seung Hong
authors.initials: SH
authors.lastname: Choi
authors.forename: Se Hyung
authors.initials: SH
authors.lastname: Kim
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Lee
authors.forename: Sun Whe
authors.initials: SW
authors.lastname: Kim
authors.forename: Joon Koo
authors.initials: JK
authors.lastname: Han
authors.forename: Byung Ihn
authors.initials: BI
authors.lastname: Choi
mesh_terms: D000328:Adult; D000368:Aged; D001650:Bile Duct Neoplasms / Q000000981:diagnostic imaging*; D001653:Bile Ducts, Intrahepatic; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging*; D018281:Cholangiocarcinoma / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008113:Liver Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000379:methods*