title: 320-row coronary computed tomography angiography (CCTA) with automatic exposure control (AEC): effect of 100 kV versus 120 kV on image quality and dose exposure.
abstract: OBJECTIVE
  To compare the impact of a 100 kV tube voltage protocol to 120 kV in terms of image quality and radiation dose by a 320 row coronary computed tomography angiography (CCTA) with automatic exposure control (AEC).
  
  
  METHODS
  Using a propensity matched analysis we compared a group of 135 patients scanned using a 100 kV tube voltage protocol with a group of 135 subjects scanned employing a 120 kV tube voltage setting. In all subjects the heart rate (HR) was <65 bpm and all CT scans were acquired using a prospective ECG gating and AEC strategy. Mean effective radiation dose and subjective and objective (Noise or N, signal to noise ratio or SNR, contrast to noise ratio or CNR) image quality, were evaluated. Subjective quality was assessed by two experienced radiologists using a 5-point scale (0: non diagnostic-4: excellent) using the 15-segment American Heart Association (AHA) coronary artery classification.
  
  
  RESULTS
  Mean effective dose and noise were non significantly different between the two groups: mean effective dose was 2.89 ± 0.7 mSv in the 100 kV group and 2.80 ± 0.57 mSv in the 120 kV group (p = 0.25) while noise was 28.9 ± 3.3 in the 120 kV group and 29.05 ± 3.6 in the 100 kV group (p = 0.72). Both SNR and CNR were significantly higher in the 100 kV group than in the 120 kV group. This data agrees with the evidence that subjective quality was significantly higher in the 100 kV group in the middle and distal segmental classes.
  
  
  CONCLUSIONS
  Our study shows that, in using a 320 row CCTA with AEC strategy it is better to employ a 100 kV tube voltage protocol because compared to 120 kV tube voltage setting, it appears to significantly improve both subjective and objective image quality without decreasing the mean effective radiation dose.
authors.affiliation: Department of Biotechnological and Applied Clinical, University of L'Aquila, Via Vetoio 1, 67100, L'Aquila, Italy. ernesto.dicesare@cc.univaq.it.
authors.forename: Ernesto
authors.initials: E
authors.lastname: Di Cesare
authors.affiliation: Department of Biotechnological and Applied Clinical, University of L'Aquila, Via Vetoio 1, 67100, L'Aquila, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Gennarelli
authors.affiliation: Department of Biotechnological and Applied Clinical, University of L'Aquila, Via Vetoio 1, 67100, L'Aquila, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Di Sibio
authors.affiliation: Department of Biotechnological and Applied Clinical, University of L'Aquila, Via Vetoio 1, 67100, L'Aquila, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Felli
authors.affiliation: Department of Biotechnological and Applied Clinical, University of L'Aquila, Via Vetoio 1, 67100, L'Aquila, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Perri
authors.affiliation: Department of Biotechnological and Applied Clinical, University of L'Aquila, Via Vetoio 1, 67100, L'Aquila, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Splendiani
authors.affiliation: Department of Biotechnological and Applied Clinical, University of L'Aquila, Via Vetoio 1, 67100, L'Aquila, Italy.
authors.forename: Giovanni Luca
authors.initials: GL
authors.lastname: Gravina
authors.affiliation: Department of Biotechnological and Applied Clinical, University of L'Aquila, Via Vetoio 1, 67100, L'Aquila, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Barile
authors.affiliation: Department of Biotechnological and Applied Clinical, University of L'Aquila, Via Vetoio 1, 67100, L'Aquila, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Masciocchi
mesh_terms: D055424:Cardiac-Gated Imaging Techniques; D000072226:Computed Tomography Angiography / Q000379:methods*; D003287:Contrast Media; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted; D059629:Signal-To-Noise Ratio; D014283:Triiodobenzoic Acids
chemical_list: D003287:Contrast Media; D014283:Triiodobenzoic Acids; C044834:iodixanol
keywords: 320-row coronary computed tomography angiography (CCTA); Image quality; Radiation dose; Tube voltage