title: Volumetric low-tube-voltage CT imaging for evaluating hypervascular hepatocellular carcinoma; effects on radiation exposure, image quality, and diagnostic performance.
abstract: OBJECTIVE
  To assess the value of hepatic arterial-phase (HAP) imaging with a low tube voltage (80 kVp), using non-helical, volumetric acquisition with a 320-detector-rows area-detector CT (ADCT) scanner for evaluating hypervascular hepatocellular carcinoma (HCC) compared with routine 120-kVp HAP imaging.
  
  
  METHODS
  This study enrolled 128 patients with 148 HCCs. Seventy-six patients with 79 HCCs underwent HAP imaging with 80 kVp obtained using a 320-detector-rows ADCT scanner. The remaining 52 patients with 69 HCCs underwent routine HAP imaging with 120 kVp obtained by 64-slice helical acquisition. Image noise and tumor to liver contrast-to-noise ratio (CNR) of the two sets of images were compared. Three radiologists evaluated both sets of images using receiver operating characteristic analyses.
  
  
  RESULTS
  Although there was a two-fold increase in the mean image noise with 80 kVp over that with 120 kVp (p < 0.001), no significant differences were observed in CNR among the two sets. The mean area under the curve (Az value) and the sensitivity for detecting HCC with 80 kVp (0.980, 78/79, respectively) were higher than that of 120 kVp (0.892, 55/69, respectively).
  
  
  CONCLUSIONS
  HAP imaging with 80 kVp obtained by an ADCT scanner significantly improves the diagnostic performance for evaluating hypervascular HCC.
authors.affiliation: Department of Radiology, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi, Japan. ichikawa@yamanashi.ac.jp
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Ichikawa
authors.forename: Utaroh
authors.initials: U
authors.lastname: Motosugi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Morisaka
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Sano
authors.forename: Muhi
authors.initials: M
authors.lastname: Ali
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Araki
mesh_terms: D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000000981:diagnostic imaging*; D003287:Contrast Media; D005260:Female; D006801:Humans; D007472:Iohexol; D008099:Liver / Q000000981:diagnostic imaging; D008113:Liver Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011446:Prospective Studies; D012372:ROC Curve; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D036542:Tomography, Spiral Computed / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol