title: Optimal phases of dynamic CT for detecting hepatocellular carcinoma: evaluation of unenhanced and triple-phase images.
abstract: BACKGROUND
  To determine the optimal phases of dynamic computed tomography (CT) for detecting hepatocellular carcinoma (HCC).
  
  
  METHODS
  Fifty-two patients with 85 HCC nodules were examined by means of unenhanced and triple-phase CT images of the whole liver. The time for obtaining the arterial-phase images was 25-55 s after intravenous bolus injection of contrast material, the time for obtaining the portal venous-phase images was 65-100 s, and the time for obtaining late-phase images was 145 s to 4 min. Detectability of the HCC nodules for all phases was statistically compared.
  
  
  RESULTS
  The detection rates for the arterial- and late-phase images were significantly higher than for the unenhanced and portal venous-phase images (p < 0.01). The combination of arterial- and late-phase images showed the same number of HCC nodules in the same number of patients as did the combination of unenhanced and triple-phase images.
  
  
  CONCLUSIONS
  The combination of the arterial- and late-phase imagings was best for detecting HCC nodules.
authors.affiliation: Department of Radiology, Osaka University Medical School, 2-2 Yamadaoka, Suita City, Osaka 565-0871, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kim
authors.forename: T
authors.initials: T
authors.lastname: Murakami
authors.forename: S
authors.initials: S
authors.lastname: Takahashi
authors.forename: K
authors.initials: K
authors.lastname: Tsuda
authors.forename: K
authors.initials: K
authors.lastname: Tomoda
authors.forename: Y
authors.initials: Y
authors.lastname: Narumi
authors.forename: H
authors.initials: H
authors.lastname: Oi
authors.forename: M
authors.initials: M
authors.lastname: Sakon
authors.forename: H
authors.initials: H
authors.lastname: Nakamura
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D006528:Carcinoma, Hepatocellular / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000473:pathology; D003287:Contrast Media / Q000008:administration & dosage; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007275:Injections, Intravenous; D007479:Iopamidol / Q000008:administration & dosage; D008113:Liver Neoplasms / Q000098:blood supply / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D003287:Contrast Media; D007479:Iopamidol