Noninvasive visualization of coronary arteries using contrast-enhanced multidetector CT: influence of heart rate on image quality and stenosis detection.
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.
Giesler
Tom
T
Department of Internal Medicine II, Universität Erlangen-Nuernberg, Ulmenweg 18, D-91054 Erlangen, Germany.
Baum
Ulrich
U
Ropers
Dieter
D
Ulzheimer
Stefan
S
Wenkel
Evelyn
E
Mennicke
Maria
M
Bautz
Werner
W
Kalender
Willi A
WA
Daniel
Werner G
WG
Achenbach
Stephan
S
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
D003287:Contrast Media