title: Detection of hypervascular hepatocellular carcinoma with dynamic magnetic resonance imaging with simultaneously obtained in-phase and opposed-phase echo images.
abstract: OBJECTIVE
  The technique of double-phase echo chemical shift gradient-echo magnetic resonance (MR) imaging with the fast low-angle shot sequence (double-echo FLASH) provides in-phase and opposed-phase (double-phase) images simultaneously. The purpose of this study was to assess whether the dynamic study with a combination of in-phase and opposed-phase (double-phase) echo images improves the detectability of hypervascular hepatocellular carcinoma (HCC) compared with that with either in-phase or opposed-phase images alone.
  
  
  METHODS
  Thirty-seven patients with 107 hypervascular HCCs who underwent the whole-liver double-phase echo dynamic MR imaging were enrolled in the study. Three radiologists blindly read in-phase images alone, opposed-phase images alone, and then double-phase images together. Sensitivity and positive predictive values as well as the areas below the alternative-free response receiver operating characteristic curve (Az values) for each imaging technique were calculated and compared statistically.
  
  
  RESULTS
  The mean sensitivity, positive predictive values, and Az values for hypervascular HCCs were 51%, 77%, and 0.52 for in-phase imaging; 55%, 86%, and 0.58 for opposed-phase imaging; and 57%, 84%, and 0.63 for double-phase imaging, respectively. The mean sensitivity for opposed-phase imaging was significantly higher than that for in-phase imaging (P < 0.05), and the mean sensitivity for double-phase imaging was higher than that for in-phase imaging (P < 0.01). The mean Az value for the double-phase imaging was significantly higher than that for in-phase imaging (P < 0.01).
  
  
  CONCLUSIONS
  Dynamic MR imaging with double-phase images was recommended for the detection of hypervascular HCC.
authors.affiliation: Department of Radiology, Osaka University Graduate School of Medicine, Suita-city, Osaka, Japan. sugihara@radiol.med.osaka-u.ac.jp
authors.forename: Eiji
authors.initials: E
authors.lastname: Sugihara
authors.forename: Takamichi
authors.initials: T
authors.lastname: Murakami
authors.forename: Tonsok
authors.initials: T
authors.lastname: Kim
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Hori
authors.forename: Manabu
authors.initials: M
authors.lastname: Takamura
authors.forename: Shuji
authors.initials: S
authors.lastname: Kawata
authors.forename: Atsuya
authors.initials: A
authors.lastname: Okada
authors.forename: Azzam Anwar
authors.initials: AA
authors.lastname: Khankan
authors.forename: Kaname
authors.initials: K
authors.lastname: Tomoda
authors.forename: Hironobu
authors.initials: H
authors.lastname: Nakamura
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis* / Q000453:epidemiology; D004311:Double-Blind Method; D017352:Echo-Planar Imaging; D005189:False Positive Reactions; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D019043:Vascular Neoplasms / Q000175:diagnosis* / Q000453:epidemiology