title: Coronary arteries: retrospectively ECG-gated multi-detector row CT angiography with selective optimization of the image reconstruction window.
abstract: OBJECTIVE
  To investigate how the technique of retrospective gating can be used to optimize reconstruction of multi-detector row computed tomographic (CT) images for each of the three major coronary arteries during the cardiac cycle.
  
  
  METHODS
  Multi-detector row coronary CT angiograms obtained in 50 patients were reconstructed at 20%-80% of the cardiac cycle in increments of 10%. Two blinded independent reviewers assessed the image quality, in terms of artifacts and visibility, obtained with three-dimensional postprocessing for segments 1-3 (right coronary artery), segments 5-8 (left main and left anterior descending coronary arteries), and segments 11 and 12 (left circumflex artery). The following grades were assigned: 1, very poor; 2, poor; 3, fair; 4, good; and 5, excellent.
  
  
  RESULTS
  The left anterior descending artery was best visualized in middiastole at 60%-70% of the cardiac cycle, and the left circumflex artery was best visualized at 50%. The optimal reconstruction window for the right coronary artery was significantly different at 40% (P < .05). Although there was good agreement (kappa = 0.75) between the two reviewers, there was a high degree of variation in the patient population.
  
  
  CONCLUSIONS
  The image reconstruction window for CT angiography of the coronary arteries should be adapted to each coronary artery. The use of one fixed time point in the cardiac cycle for image reconstruction does not provide optimal image quality.
authors.affiliation: Department of Diagnostic Radiology, Eberhard-Karls-University Tuebingen, Hoppe-Seyler-Strasse 3, 72076 Tuebingen, Germany. andreas.kopp@uni-tuebingen.de
authors.forename: A F
authors.initials: AF
authors.lastname: Kopp
authors.forename: S
authors.initials: S
authors.lastname: Schroeder
authors.forename: A
authors.initials: A
authors.lastname: Kuettner
authors.forename: M
authors.initials: M
authors.lastname: Heuschmid
authors.forename: C
authors.initials: C
authors.lastname: Georg
authors.forename: B
authors.initials: B
authors.lastname: Ohnesorge
authors.forename: R
authors.initials: R
authors.lastname: Kuzo
authors.forename: C D
authors.initials: CD
authors.lastname: Claussen
mesh_terms: D000368:Aged; D017023:Coronary Angiography; D004562:Electrocardiography; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction; D014057:Tomography, X-Ray Computed