title: Superior CT coronary angiography image quality at lower radiation exposure with second generation 320-detector row CT in patients with elevated heart rate: a comparison with first generation 320-detector row CT.
abstract: BACKGROUND
  This study aims to compare the image quality of second generation versus first generation 320-computed tomography coronary angiography (CTCA) in patients with heart rate ≥65 bpm as it has not been specifically reported.
  
  
  METHODS
  Consecutive patients who underwent CTCA using second-generation-320-detector-row-CT were prospectively enrolled. A total of 50 patients with elevated (≥65 bpm) heart rate and 50 patients with controlled (<65 bpm) heart rate were included. Age and gender matched patients who were scanned with the first-generation-320-detector-row-CT were retrospectively identified. Image quality in each coronary artery segment was assessed by two blinded CT angiographers using the five-point Likert scale.
  
  
  RESULTS
  In the elevated heart rate cohorts, while there was no significant difference in heart rate during scan-acquisition (66 vs. 69 bpm, P=0.308), or body mass index (28.5 vs. 29.6, P=0.464), the second generation scanner was associated with better image quality (3.94±0.6 vs. 3.45±0.8, P=0.001), and with lower radiation (2.8 vs. 4.3 mSv, P=0.009). There was no difference in scan image quality for the controlled heart rate cohorts.
  
  
  CONCLUSIONS
  The second generation CT scanner provides better image quality at lower radiation dose in patients with elevated heart rate (≥65 bpm) compared to first generation CT scanner.
authors.affiliation: 1 Monash Heart, Monash Cardiovascular Research Centre & Monash University, Clayton, Victoria, Australia ; 2 Department of Diagnostic Imaging, MMC, Southern Health, Melbourne, Australia.
authors.forename: Dennis T L
authors.initials: DT
authors.lastname: Wong
authors.affiliation: 1 Monash Heart, Monash Cardiovascular Research Centre & Monash University, Clayton, Victoria, Australia ; 2 Department of Diagnostic Imaging, MMC, Southern Health, Melbourne, Australia.
authors.forename: Siang Y
authors.initials: SY
authors.lastname: Soh
authors.affiliation: 1 Monash Heart, Monash Cardiovascular Research Centre & Monash University, Clayton, Victoria, Australia ; 2 Department of Diagnostic Imaging, MMC, Southern Health, Melbourne, Australia.
authors.forename: Brian S H
authors.initials: BS
authors.lastname: Ko
authors.affiliation: 1 Monash Heart, Monash Cardiovascular Research Centre & Monash University, Clayton, Victoria, Australia ; 2 Department of Diagnostic Imaging, MMC, Southern Health, Melbourne, Australia.
authors.forename: James D
authors.initials: JD
authors.lastname: Cameron
authors.affiliation: 1 Monash Heart, Monash Cardiovascular Research Centre & Monash University, Clayton, Victoria, Australia ; 2 Department of Diagnostic Imaging, MMC, Southern Health, Melbourne, Australia.
authors.forename: Marcus
authors.initials: M
authors.lastname: Crossett
authors.affiliation: 1 Monash Heart, Monash Cardiovascular Research Centre & Monash University, Clayton, Victoria, Australia ; 2 Department of Diagnostic Imaging, MMC, Southern Health, Melbourne, Australia.
authors.forename: Arthur
authors.initials: A
authors.lastname: Nasis
authors.affiliation: 1 Monash Heart, Monash Cardiovascular Research Centre & Monash University, Clayton, Victoria, Australia ; 2 Department of Diagnostic Imaging, MMC, Southern Health, Melbourne, Australia.
authors.forename: John
authors.initials: J
authors.lastname: Troupis
authors.affiliation: 1 Monash Heart, Monash Cardiovascular Research Centre & Monash University, Clayton, Victoria, Australia ; 2 Department of Diagnostic Imaging, MMC, Southern Health, Melbourne, Australia.
authors.forename: Ian T
authors.initials: IT
authors.lastname: Meredith
authors.affiliation: 1 Monash Heart, Monash Cardiovascular Research Centre & Monash University, Clayton, Victoria, Australia ; 2 Department of Diagnostic Imaging, MMC, Southern Health, Melbourne, Australia.
authors.forename: Sujith K
authors.initials: SK
authors.lastname: Seneviratne
keywords: 320-detector row; Image quality; computed tomography (CT); likert scale; radiation dose