title: Clinical evaluation of automatic tube voltage selection in chest CT angiography.
abstract: OBJECTIVE
  To evaluate the clinical impact of automatic tube voltage selection on chest CT angiography (CTA).
  
  
  METHODS
  Ninety-three patients were prospectively evaluated with a CT protocol aimed at comparing two successive CTAs acquired under similar technical conditions except for the kV selection: (1) the initial CTA was systematically obtained at 120 kVp and 90 ref mAs; (2) the follow-up CTA was obtained with an automatic selection of the kilovoltage (Care KV; Siemens Healthcare) for optimised CTA.
  
  
  RESULTS
  At follow-up, 90 patients (97 %) underwent CTA with reduced tube voltage, 100 kV (n = 26; 28 %) and 80 kV (n = 64; 69 %), resulting in a significant dose-length-product reduction (follow-up: 87.27; initial: 141.88 mGy.cm; P < 0.0001; mean dose reduction: 38.5 %) and a significant increase in the CNR at follow-up (follow-up: 11.5 ± 3.5 HU; initial: 10.9 ± 3.7 HU; P = 0.03). The increase in objective image noise at follow-up (follow-up: 23.2 ± 6.7 HU vs. 17.8 ± 5.1 HU; P < 0.0001) did not alter the diagnostic value of images.
  
  
  CONCLUSIONS
  Automatic tube voltage selection reduced the radiation dose delivered during chest CT angiograms by 38.5 % while improving the contrast-to-noise ratio of the examinations.
  
  
  CONCLUSIONS
  • As low a dose as possible must be used for CT angiography. • Automatic tube voltage selection permits reduced patient exposure. • Lowering the kVp enables increased intravascular attenuation. • Automatic tube voltage selection does not compromise the overall image quality.
authors.affiliation: Department of Thoracic Imaging, Hospital Calmette (EA 2694), University Lille Nord de France, 59000, Lille, France.
authors.forename: Tilo
authors.initials: T
authors.lastname: Niemann
authors.forename: Simon
authors.initials: S
authors.lastname: Henry
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Faivre
authors.forename: Kanna
authors.initials: K
authors.lastname: Yasunaga
authors.forename: Sofiane
authors.initials: S
authors.lastname: Bendaoud
authors.forename: Ariana
authors.initials: A
authors.lastname: Simeone
authors.forename: Jacques
authors.initials: J
authors.lastname: Remy
authors.forename: Alain
authors.initials: A
authors.lastname: Duhamel
authors.forename: Thomas
authors.initials: T
authors.lastname: Flohr
authors.forename: Martine
authors.initials: M
authors.lastname: Remy-Jardin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011829:Radiation Dosage; D011835:Radiation Protection / Q000379:methods*; D011856:Radiographic Image Enhancement / Q000379:methods*; D013902:Radiography, Thoracic / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*