title: Reduced radiation dose and improved image quality at cardiovascular CT angiography by automated attenuation-based tube voltage selection: intra-individual comparison.
abstract: OBJECTIVE
  To evaluate the effect of automated tube voltage selection on radiation dose and image quality at cardiovascular CT angiography (CTA).
  
  
  METHODS
  We retrospectively analysed paired studies in 72 patients (41 male, 60.5 ± 16.5 years), who had undergone CTA acquisitions of the heart or aorta both before and after the implementation of an automated x-ray tube voltage selection algorithm (ATVS). All other parameters were kept identical between the two acquisitions. Subjective image quality (IQ) was rated and objective IQ was measured by image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and figure of merit (FOM). Image quality parameters and effective dose were compared between acquisitions.
  
  
  RESULTS
  Overall subjective image quality improved with the percentage of cases scored as adequate or higher increasing from 79 % to 92 % after implementation of ATVS (P = 0.03). SNR (14.1 ± 5.9, 15.7 ± 6.1, P = 0.009), CNR (11.6 ± 5.3, 13.2 ± 5.6, P = 0.011), and FOM (19.9 ± 23.3, 43.8 ± 51.1, P < 0.001) were significantly higher after implementation of ATVS. Mean image noise (24.1 ± 8.4 HU, 22.7 ± 7.1 HU, P = 0.048) and mean effective dose (10.6 ± 5.9 mSv, 8.8 ± 5.0 mSv, P = 0.003) were significantly lower after implementation of ATVS.
  
  
  CONCLUSIONS
  Automated tube voltage selection can operator-independently optimize cardiovascular CTA image acquisition parameters with improved image quality at reduced dose.
  
  
  CONCLUSIONS
  • Automatic tube voltage selection optimizes tube voltage for each individual patient. • In this population, overall radiation dose decreased while image quality improved. • This tool may become valuable for improving dose/quality ratio.
authors: Department of Radiology and Radiological Science, Medical University of South Carolina, Ashley River Tower, MSC 226 25 Courtenay Drive, Charleston, SC, 29425, USA.
authors: Aleksander W
authors: AW
authors: Krazinski
authors: Felix G
authors: FG
authors: Meinel
authors: U Joseph
authors: UJ
authors: Schoepf
authors: Justin R
authors: JR
authors: Silverman
authors: Christian
authors: C
authors: Canstein
authors: Carlo N
authors: CN
authors: De Cecco
authors: Lucas L
authors: LL
authors: Geyer
mesh_terms: D000368:Aged; D000465:Algorithms; D000792:Angiography / Q000379:methods*; D003287:Contrast Media; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging*; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media