title: Noninvasive visualization of coronary arteries using contrast-enhanced multidetector CT: influence of heart rate on image quality and stenosis detection.
abstract: OBJECTIVE
  Although multidetector CT (MDCT) with retrospectively ECG-gated image reconstruction has been shown to permit noninvasive visualization of the coronary arteries, the 125-250 msec required for image acquisition frequently causes motion artifacts. We investigated the influence of a patient's heart rate on the presence of motion artifacts and on accuracy of stenosis detection on contrast-enhanced MDCT.
  
  
  METHODS
  In 100 patients, MDCT was performed, and ECG-gated cross-sectional images were retrospectively reconstructed. From the 10 data sets obtained for each patient (reconstructed at 0-90% of the cardiac cycle in increments of 10%), we chose the best data set for every coronary artery. The images of the arteries were evaluated for occurrence of artifacts and the presence of high-grade stenosis (diameter reduction exceeding 70%) or occlusions. MDCT results were compared with coronary angiographic findings.
  
  
  RESULTS
  Of the 400 coronary arteries, 115 (29%) could not be evaluated because of motion artifacts (n = 84) or other reasons (n = 31). Overall, 51 (49%) of 104 stenoses were revealed on MDCT. For detecting stenosis in those arteries that we could evaluate, MDCT had a sensitivity of 91% (51 of 56 stenoses detected) and a specificity of 89%. As the heart rate increased, the number of arteries that could be evaluated decreased, and overall sensitivity for stenosis detection decreased from 62% (heart rate < or = 70 beats per minute) to 33% (heart rate > 70 beats per minute).
  
  
  CONCLUSIONS
  MDCT can reveal coronary stenoses, but the usefulness of MDCT as an aid in accurately evaluating stenoses decreases as a patient's heart rate increases.
authors.affiliation: Department of Internal Medicine II, Universität Erlangen-Nuernberg, Ulmenweg 18, D-91054 Erlangen, Germany.
authors.forename: Tom
authors.initials: T
authors.lastname: Giesler
authors.forename: Ulrich
authors.initials: U
authors.lastname: Baum
authors.forename: Dieter
authors.initials: D
authors.lastname: Ropers
authors.forename: Stefan
authors.initials: S
authors.lastname: Ulzheimer
authors.forename: Evelyn
authors.initials: E
authors.lastname: Wenkel
authors.forename: Maria
authors.initials: M
authors.lastname: Mennicke
authors.forename: Werner
authors.initials: W
authors.lastname: Bautz
authors.forename: Willi A
authors.initials: WA
authors.lastname: Kalender
authors.forename: Werner G
authors.initials: WG
authors.lastname: Daniel
authors.forename: Stephan
authors.initials: S
authors.lastname: Achenbach
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016477:Artifacts; D003287:Contrast Media; D017023:Coronary Angiography; D003327:Coronary Disease / Q000000981:diagnostic imaging*; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D003287:Contrast Media