title: Coronary artery calcium scoring using ECG-gated multidetector CT: effect of individually optimized image-reconstruction windows on image quality and measurement reproducibility.
abstract: OBJECTIVE
  We studied the effect of using individually optimized image-reconstruction windows on image quality and measurement reproducibility in coronary artery calcium scoring using ECG-gated multidetector CT (MDCT).
  
  
  METHODS
  In 50 patients, the coronary arteries were investigated twice with ECG-gated MDCT with 500-msec rotation time. Per scan, three sets of images were reconstructed, respectively, at an image-reconstruction window of 40%, 50%, and 60% of the R-R interval. Image quality was assessed, and the optimal image-reconstruction window per scan and per coronary territory was determined. The interscan variability of calcium mass measurements was calculated for different strategies (use of fixed image-reconstruction window [40%, 50%, or 60%] versus individually optimized image-reconstruction window).
  
  
  RESULTS
  A significant improvement in image quality was obtained by selecting the best of three reconstructed data sets (mean image quality score, 4.4 vs 3.7; p < 0.001). Even with individually optimized image-reconstruction window values, we obtained high values for interscan variability (mean +/- SD, 27% +/- 22% vs 31% +/- 35% with a fixed image-reconstruction window).
  
  
  CONCLUSIONS
  The use of individually optimized image-reconstruction windows leads to a significant improvement in image quality. However, interscan variability of calcium mass measurements remains high.
mesh_terms: D000368:Aged; D002114:Calcinosis / Q000000981:diagnostic imaging*; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000295:instrumentation* / Q000379:methods*