title: Coronary image quality of 320-MDCT in patients with heart rates above 65 beats per minute: preliminary experience.
abstract: OBJECTIVE
  High heart rate may negatively influence the image quality of cardiac CT. The technical advances of 320-MDCT may overcome issues with poor image quality associated with high heart rate. This study aimed to evaluate the coronary image quality of 320-MDCT in patients with heart rates above 65 beats/min.
  
  
  METHODS
  Patients who presented for cardiac CT were divided into two groups according to heart rate, either greater than 65 beats/min or less than or equal to 65 beats/min. Two radiologists were blinded to the patient groups and evaluated images of 15 coronary artery segments per patient using 320-MDCT with consensus agreement. The image quality was scored subjectively as 1 or 2 (diagnostic quality) or 3 (poor quality and nondiagnostic).
  
  
  RESULTS
  There were no statistically significant differences between the two groups in terms of age, sex, and body mass index (p > 0.05). The median heart rate was 70 beats/min (range, 67-110 beats/min) for the group with heart rate greater than 65 beats/min and 60 beats/min (range, 48-65 beats/min) for the group with heart rate less than or equal to 65 beats/min (p < 0.001). In patients with heart rates greater than 65 beats/min, diagnostic quality images (scores of 1 or 2) were obtained in 95.6% of the analyzed segments, compared with 96.9% in the group with heart rate less than or equal to 65 beats/min (p = 0.7).
  
  
  CONCLUSIONS
  Our initial evaluation suggests that coronary artery images of diagnostic quality can be obtained using 320-MDCT in most patients with heart rates greater than 65 beats/min, in percentages similar to those for patients with heart rates less than or equal to 65 beats/min. This finding may be the result of the inherent image acquisition and reconstruction technique of 320-MDCT.
authors: Department of Diagnostic Imaging, Monash Medical Centre, Southern Health, 246 Clayton Rd, Clayton, Victoria 3168, Australia.
authors: Allan B
authors: AB
authors: Lee
authors: Dee
authors: D
authors: Nandurkar
authors: Michal E
authors: ME
authors: Schneider-Kolsky
authors: Marcus
authors: M
authors: Crossett
authors: Sujith K
authors: SK
authors: Seneviratne
authors: James D
authors: JD
authors: Cameron
authors: John M
authors: JM
authors: Troupis