title: Diagnostic performance of high-definition coronary computed tomography angiography performed with multiple radiation dose reduction strategies.
abstract: BACKGROUND
  Numerous radiation dose reduction measures have been proposed for coronary computed tomographic angiography (CCTA). Although these techniques allow for imaging with reduced radiation, it is unknown whether diagnostic performance is maintained. A new high-definition CCTA (HD-CCTA) allows higher spatial resolution, reduced image noise, and lower radiation doses.
  
  
  OBJECTIVE
  The aim of this study was to determine the diagnostic performance of HD-CCTA, in combination with multiple radiation dose reduction strategies, for the detection of obstructive coronary artery disease.
  
  
  METHODS
  Consecutive patients (N = 43, aged 60 ± 10 years, 83% male) with chest pain and referred for quantitative coronary angiography (QCA) underwent HD-CCTA with radiation dose reduction measures, including prospective electrocardiographic triggering, reduction of additional tube on-time, and minimization of tube voltage and current. Intraluminal diameter stenosis ≥ 50% was considered significant. QCA served as the reference standard. The area under the receiver-operating-characteristic curve (AUC) was used to evaluate diagnostic accuracy.
  
  
  RESULTS
  All scans demonstrated diagnostic image quality, with 99% (543/548) of included coronary segments interpretable by HD-CCTA. Median effective radiation dose was 2.8 mSv (interquartile range, 1.3-3.9). The AUC for the per-patient assessment for stenosis ≥ 50% was 0.90 (95% confidence interval [CI], 0.77-0.96), with sensitivity of 95% (95% CI, 85%-100%), specificity of 79% (95% CI, 63%-95%), positive predictive value of 78% (95% CI, 61%-95%), and negative predictive value of 95% (95% CI, 85%-100%).
  
  
  CONCLUSIONS
  Compared with QCA, HD-CCTA with multiple dose reduction measures resulted in low radiation doses and high diagnostic accuracy to detect and exclude obstructive coronary artery disease.
authors.affiliation: Department of Internal Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Bobak
authors.initials: B
authors.lastname: Heydari
authors.forename: Jonathon
authors.initials: J
authors.lastname: Leipsic
authors.forename: G B John
authors.initials: GB
authors.lastname: Mancini
authors.forename: James K
authors.initials: JK
authors.lastname: Min
authors.forename: Troy
authors.initials: T
authors.lastname: Labounty
authors.forename: C
authors.initials: C
authors.lastname: Taylor
authors.forename: Gabriela V Cohen
authors.initials: GV
authors.lastname: Freue
authors.forename: Brett
authors.initials: B
authors.lastname: Heilbron
mesh_terms: D000368:Aged; D017023:Coronary Angiography / Q000379:methods*; D023921:Coronary Stenosis / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed / Q000379:methods*