title: Image quality with single-heartbeat 320-multidetector computed tomographic coronary angiography.
abstract: OBJECTIVE
  We aimed to establish the feasibility of single-heartbeat 320-multidetector computed tomographic coronary angiography (CTCA) and assess variables affecting image quality.
  
  
  METHODS
  Consecutive patients (n = 249, 38% male) underwent CTCA. Two observers assessed image quality using a 4-point scale (1, excellent; 4, poor).
  
  
  RESULTS
  Mean heart rate was 60 beats per minute (95% confidence interval, 59-62); body mass index, 29 kg/m (28-30); and dose-length product, 283 mGy·cm (266-301). During scanning, 133 (51%) received sublingual glyceryl trinitrate (GTN), 9 (4%) had ectopics, and 12 (5%) had atrial fibrillation. Diagnostic image quality was obtained in 99% with mean image quality of 1.4 (1.3, 1.5). Age, sex, atrial fibrillation, ectopics, diabetes mellitus (12%), and obstructive disease were not related to image quality. A lower heart rate and GTN were associated with improved image quality (P ≤ 0.001).
  
  
  CONCLUSIONS
  Optimal image quality in single-heartbeat 320-multidetector CTCA is achievable in 99% of unselected patients. Image quality is improved by lower heart rate and GTN.
authors.affiliation: From the *University of Edinburgh/British Heart Foundation Centre for Cardiovascular Science, †Clinical Research Imaging Centre, University of Edinburgh; and ‡Royal Infirmary of Edinburgh, Edinburgh, United Kingdom.
authors.forename: Michelle Claire
authors.initials: MC
authors.lastname: Williams
authors.forename: Nicholas W
authors.initials: NW
authors.lastname: Weir
authors.forename: Saeed
authors.initials: S
authors.lastname: Mirsadraee
authors.forename: Anne E
authors.initials: AE
authors.lastname: Scott
authors.forename: Neal G
authors.initials: NG
authors.lastname: Uren
authors.forename: Graham
authors.initials: G
authors.lastname: McKillop
authors.forename: Edwin J R
authors.initials: EJ
authors.lastname: van Beek
authors.forename: John H
authors.initials: JH
authors.lastname: Reid
authors.forename: David E
authors.initials: DE
authors.lastname: Newby
mesh_terms: D000465:Algorithms; D055424:Cardiac-Gated Imaging Techniques / Q000379:methods*; D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D005240:Feasibility Studies; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D015588:Observer Variation; D011856:Radiographic Image Enhancement / Q000379:methods*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity