title: Early hepatocellular carcinoma: three-phase helical CT features of 16 patients.
abstract: OBJECTIVE
  To evaluate the three-phase helical CT features of early hepatocellular carcinomas, based on the new Japanese classification.
  
  
  METHODS
  Over the course of an eight-year period, we collected 16 pathologically proven early hepatocellular carcinomas from 16 patients having undergone a three-phase helical CT prior to surgery. The three-phase CT images were acquired at 20-35 sec (arterial phase), 70 sec (portal phase), and 180 sec (equilibrium phase) from the beginning of intravenous injection of contrast material. All the CT images were retrospectively analyzed by two radiologists in consensus, based on their description of morphologic (size, margin, fibrous capsule and mosaic pattern) and enhancement patterns of tumors.
  
  
  RESULTS
  Only seven (44%) of the 16 early hepatocellular carcinomas having undergone a CT were described (mean diameter, 1.2 cm; range, 0.4-2.5 cm). All the tumors had an ill-defined margin with no fibrous capsule. The mosaic pattern was found in only one tumor. Only three (43%) of the seven tumors detected on CT were hyperattenuating during the arterial phase. The four remaining tumors (25%) were hypoattenuating throughout the three phases.
  
  
  CONCLUSIONS
  Despite the higher resolution provided by the three phase scans, the contrast-enhanced CT provides only limited detection of the variable morphologic and enhancement features of early hepatocellular carcinomas.
authors.affiliation: Department of Radiology and Center of Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. wjlee@skku.edu
authors.forename: Jongmee
authors.initials: J
authors.lastname: Lee
authors.forename: Won Jae
authors.initials: WJ
authors.lastname: Lee
authors.forename: Hyo Keun
authors.initials: HK
authors.lastname: Lim
authors.forename: Jae Hoon
authors.initials: JH
authors.lastname: Lim
authors.forename: Nami
authors.initials: N
authors.lastname: Choi
authors.forename: Mi-hyun
authors.initials: MH
authors.lastname: Park
authors.forename: Sang Won
authors.initials: SW
authors.lastname: Kim
authors.forename: Cheol Keun
authors.initials: CK
authors.lastname: Park
mesh_terms: D000328:Adult; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D036542:Tomography, Spiral Computed