title: Comparison of standard- and low-tube voltage MDCT angiography in patients with peripheral arterial disease.
abstract: OBJECTIVE
  We investigated the effect of low-tube-voltage CT angiography with a reduced volume of contrast agent on qualitative and quantitative parameters and the radiation dose in patients with peripheral arterial disease.
  
  
  METHODS
  Eighty consecutive patients were divided into two groups; the protocol was 120 kVp and 1.8 ml/kg contrast agent (300 mgI/ml) in one group and 80 kVp and 1.2 ml/kg in the other. For quantitative analysis we calculated the mean arterial attenuation, the mean difference between maximum and minimum attenuation values, contrast-to-noise ratio (CNR), and figure of merit (FOM). For qualitative evaluation, we used visual scores.
  
  
  RESULTS
  There were no significant intergroup differences in mean arterial attenuation (120 vs. 80 kVp: 331.6 ± 61.6 vs. 354.9 ± 61.9 HU) and in the mean difference between maximum and minimum attenuation (120 vs. 80 kVp: 52.2 ± 25.5 vs. 61.5 ± 27.5 HU). While the mean CNR was significantly higher at 120 than 80 kVp (38.4 ± 18.8 vs. 31.1 ± 15.3), the mean FOM was not significantly different (120 vs. 80 kVp: 1.3 ± 1.5 vs. 1.2 ± 1.2), and there was no significant intergroup difference in visual scores. The mean dose-length product was significantly lower at 80 than 120 kVp (1,024.3 ± 151.3 vs. 1,464.7 ± 208.7 mGy·cm).
  
  
  CONCLUSIONS
  The 80-kVp protocol allows for reduction of the radiation dose by approximately 30% and the volume of contrast agent by more than 30% without deterioration of vascular enhancement and image quality.
authors.affiliation: Department of Diagnostic Radiology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1, Honjo, Kumamoto-shi, Kumamoto, 860-8556, Japan. utsunomi@kumamoto-u.ac.jp
authors.forename: Daisuke
authors.initials: D
authors.lastname: Utsunomiya
authors.forename: Seitaro
authors.initials: S
authors.lastname: Oda
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Funama
authors.forename: Kazuo
authors.initials: K
authors.lastname: Awai
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nakaura
authors.forename: Yumi
authors.initials: Y
authors.lastname: Yanaga
authors.forename: Toshinori
authors.initials: T
authors.lastname: Hirai
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yamashita
mesh_terms: D000368:Aged; D000792:Angiography; D003287:Contrast Media; D005260:Female; D006801:Humans; D007866:Leg / Q000098:blood supply*; D008297:Male; D058729:Peripheral Arterial Disease / Q000000981:diagnostic imaging*; D011829:Radiation Dosage; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods
chemical_list: D003287:Contrast Media