Background: 16-slice multislice computed tomography (MSCT) has been used as a noninvasive method to evaluate coronary anatomy. But, despite of good sensitivity & negative predictive value, poor specificity & positive predictive value limit the clinical efficacy. This study was aimed to determine the diagnostic accuracy of 64-sclice MSCT for the detection of significant coronary artery disease. Method: In 49 patients scheduled for conventional coronary angiography, 64-slice MSCT was performed and evaluated for the presence of significant (���50% luminal narrowing) stenosis from March 2006 through July 2006. 3 patients were excluded because of poor quality. In 46 patients ( 31 males, 15 females; 59.5 짹 10.2 years). Of these segments & vessels, 711(96.6%) segments & 180(97.8%) vessels were of sufficient image quality. Result: Conventional coronary angiography identified 77 segments, 38 vessels, of which 85 segment, 44 vessels were detected by 64-slice MSCT. The corresponding sensitivity, specificity, positive predictive value, negative predictive value for segment were 95.1%, 98.6%, 90.6%, 99.3% respectively. In vessel analysis, sensitivity, specificity, positive predictive value, negative predictive value were 92.7%, 95.7%, 86.4%, 97.8%. These findings were displayed in Table 1. as below. Conclusion : The present study confirms that the specificity & positive predictive value of significant stenotic coronary artery of 64-slice MSCT improved in compared with that of the 16-sclice MSCT. 64-sclice MSCT enables the accurate and noninvasive evaluation of significant coronary artery stenosis in clinical fields.