Myocardial perfusion imaging (MPI) is sensitive method for assessing the functional significance of coronary stenosis and risk stratification. Coronary CT angiography (CTA) has delivered high negative predictive value in the validation of coronary lesions. This retrospective analysis compared the accuracies of stress MPI with CTA, CTA alone and MPI alone in the detection of coronary stenosis. METHODS: Two thirty-nine patients with suspected coronary artery disease were studied. Group A : 202 patients ( 121 male, mean : 65.8짹9.7 y-o) were performed stress MPI with CTA. They underwent stress MPI without rest MPI and CTA at same or next day. The two images were analyzed by one experienced observer. Group B : 37 patients ( 24 male, mean : 61짹12 y-o) were performed MPI and CTA, respectively. MPI were analyzed by experienced observers, and reversible and fixed perfusion defects were allocated to their corresponding coronary vessels. For the evaluation of CTA, lesions > or = 50% and luminal narrowing < 50% were visually assessed by experienced observers. We compared each report to CAC. RESULTS: Eight hundred eight coronary vessels in group A, 148 in group B were analyzed. Sensitivity, specificity, and negative and positive predictive values were 97.5%, 73.2 %, 93.5%, and 88.9 %, respectively, for the ability of stress MPI with CTA to detect coronary stenosis by patient analysis. And also 92.3 %, 72.7 %, 88.9 % and 80 % for CTA and 92.6 %, 40 % 80.6 % and 66.7 % for MPI were calculated, respectively. In LAD analysis, sensitivity, specificity, and negative and positive predictive values were 92.2%, 82.8%, 87.6 % and 88.9% in group A, 76.2%, 75.0%, 80.0% and 75.0% in CTA and 72.7%, 80%, 84.2% and 66.7% in MPI, respectively. In LCX analysis, those values were 86.8%, 91.0%, 83.1% and 93.1% in group A, 84.6%, 83.3%, 73.3% and 90.9% in CTA and 28.6%, 91.3%, 66.7% and 67.7% in MPI, respectively. In RCA analysis, those values were 91.9%, 94.8%, 92.9% and 94.2% in group A, 70.6%, 85.0%, 80.0% and 77.3%in CTA and 93.8%, 61.9%, 65.2% and 92.9%in MPI, respectively.CONCLUSION: Stress MPI with CTA detected myocardial ischemia with higher accuracy compared with CTA alone or MPI alone.