title: CT coronary angiography: influence of different cardiac reconstruction intervals on image quality and diagnostic accuracy.
abstract: OBJECTIVE
  To prospectively analyze image quality and diagnostic accuracy of different reconstruction intervals of coronary angiography using multislice computed tomography (MSCT).
  
  
  METHODS
  For each of 47 patients, 10 ECG-gated MSCT reconstructions were generated throughout the RR interval from 0 to 90%, resulting in altogether 470 datasets. These datasets were randomly analyzed for image quality and accuracy and compared with conventional angiography. Statistical comparison of intervals was performed using nonparametric analysis for repeated measurements to account for clustering of arteries within patients.
  
  
  RESULTS
  Image reconstruction intervals centered at 80, 70, and 40% of the RR interval resulted (in that order) in the best overall image quality for all four main coronary vessels. Eighty percent reconstructions also yielded the highest diagnostic accuracy of all intervals. The combination of the three best intervals (80, 70, and 40%) significantly reduced the nondiagnostic rate as compared with 80% alone (p=0.005). However, the optimal reconstruction interval combination achieved significantly improved specificities and nondiagnostic rates (p<0.05). The optimal combination consisted of 1.7+/-0.9 reconstruction intervals on average. In approximately half of the patients (49%, 23/47) a single reconstruction was optimal. In 18 (38%), 3 (6%), and 3 (6%) patients one, two, and three additional reconstruction intervals were required, respectively, to achieve optimal quality. In 28% of the patients the optimal combination consisted of reconstructions other than the three best intervals (80, 70, and 40%).
  
  
  CONCLUSIONS
  Multiple image reconstruction intervals are essential to ensure high image quality and accuracy of CT coronary angiography.
authors.affiliation: Department of Radiology, Charité Medical School, Humboldt-Universität zu Berlin, Germany. marc.dewey@charite.de
authors.forename: Marc
authors.initials: M
authors.lastname: Dewey
authors.forename: Florian
authors.initials: F
authors.lastname: Teige
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Rutsch
authors.forename: Tania
authors.initials: T
authors.lastname: Schink
authors.forename: Bernd
authors.initials: B
authors.lastname: Hamm
mesh_terms: D017023:Coronary Angiography / Q000379:methods*; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*