title: Evaluation of reconstruction windows for multislice computed tomography in quantification of coronary calcium.
abstract: OBJECTIVE
  To search for an optimum reconstruction window in retrospectively gated multislice computed tomography (MSCT) for quantification of coronary calcium.
  
  
  METHODS
  Coronary calcium quantified was examined as Agatston and volume scores by two experienced observers at 10 time points across the R-R interval of the electrocardiogram in 42 patients. A combination of statistical approaches was used to evaluate the distributions of minimum and maximum scores and of interobserver variability for both scoring methods across the cardiac cycle.
  
  
  RESULTS
  Based on the combination of evaluation approaches, 60% to 70% of the R-R interval appeared to be the optimum time point for obtaining maximum calcium scores with minimum interobserver variability. The optimum time point was more clearly defined for the Agatston score than for the volume score.
  
  
  CONCLUSIONS
  A reconstruction window beginning at 60% to 70% of the R-R interval seems to be most advantageous for retrospective gating of MSCT studies performed to quantify coronary calcium.
authors.affiliation: Department of Radiology, Mayo Clinic, Jacksonville, Florida 32224, USA. gerber.thomas@mayo.edu
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Gerber
authors.forename: Peter C
authors.initials: PC
authors.lastname: O'Brien
authors.forename: Kathy
authors.initials: K
authors.lastname: Pastor
authors.forename: Ronald S
authors.initials: RS
authors.lastname: Kuzo
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Blackshear
authors.forename: Richard L
authors.initials: RL
authors.lastname: Morin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D002114:Calcinosis / Q000000981:diagnostic imaging*; D016009:Chi-Square Distribution; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009010:Monte Carlo Method; D015588:Observer Variation; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*