title: Whole-body CT angiography with low tube voltage and low-concentration contrast material to reduce radiation dose and iodine load.
abstract: OBJECTIVE
  The purpose of this study was to prospectively evaluate the contrast enhancement, vascular depiction, image quality, and radiation dose of low-tube-voltage whole-body CT angiography (CTA) performed with low-concentration iodinated contrast material.
  
  
  METHODS
  Whole-body CTA was performed on 109 patients with a 64-MDCT scanner. Patients were randomized into three groups: CTA with 240-mg/mL contrast material at 80 kVp (240-80 group), 300-mg/mL at 80 kVp (300-80 group), and 370-mg/mL at 120 kVp (370-120 group). Signal-to-noise ratio (SNR), arterial depiction, image quality, and radiation dose were assessed. Figure of merit was computed to normalize signal-to-noise ratio, estimated effective dose, and iodine weight.
  
  
  RESULTS
  In the 240-80 group, the mean load of administered iodine was 21.6 g; for the 300-80 group, 26.8 g; and the 370-120 group, 34.0 g (p < 0.05). The ranges of mean vascular enhancement were 508-521 HU, 546-593 HU, and 435-442 HU (p < 0.05). Arterial depiction and image quality were comparable for the 240-80 and 370-120 groups and were greater for the 300-80 group than the other two groups in selected arteries (p < 0.05). Effective dose was higher (p < 0.05) in the 370-120 group (2.8-5.4 mSv) than in the others (2.3-4.3 mSv). The figure of merit in the 240-80 group was greater than (p < 0.05) or comparable to that in the 370-120 group.
  
  
  CONCLUSIONS
  Use of 240-mg/mL contrast material at 80 kVp seems appropriate for routine whole-body CTA and beneficial for reduction of iodine load and radiation dose, whereas use of 300-mg/mL contrast material may marginally improve delineation of selected small arteries.
authors.affiliation: 1 Department of Radiology, Gifu University Hospital, 1-1 Yanagido, Gifu 501-1194.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kanematsu
authors.forename: Satoshi
authors.initials: S
authors.lastname: Goshima
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Miyoshi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kondo
authors.forename: Haruo
authors.initials: H
authors.lastname: Watanabe
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Noda
authors.forename: Kyongtae T
authors.initials: KT
authors.lastname: Bae
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000379:methods*; D003287:Contrast Media / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D007472:Iohexol / Q000008:administration & dosage; D007479:Iopamidol / Q000008:administration & dosage; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011829:Radiation Dosage; D059629:Signal-To-Noise Ratio; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014283:Triiodobenzoic Acids / Q000008:administration & dosage; D014652:Vascular Diseases / Q000000981:diagnostic imaging*; D051598:Whole Body Imaging
chemical_list: D003287:Contrast Media; D014283:Triiodobenzoic Acids; D007472:Iohexol; D007479:Iopamidol; C054871:ioversol