Background: The coronary artery disease, now, the incidence is increasing in both developed and developing countries. The investigation is evoluted and non-invasive multislice CT scanners have been used more frequently, although the gold standard is still the coronary angiography.
Objective: To investigate the accuracy in detected coronary artery disease by using 16-slice CT scanners compared to the conventional coronary angiography.
Material and Method: Fifty-five patients were 43 males, 12 females, median aged 62 years (43-82 years), and average heart rates 67 beats/minute (46-147 beats/minute) had the ECG-gated CT angiography followed by coronary angiography in 3 months. The ECG-gated CT angiography was performed by using16-slice MSCT detector (0.42-s rotation time, 16 x 0.75-mm detector collimation).
Results: All patients were classified into two major groups; one was significant coronary artery stenosis which was designed by stenosis at least 50% and the other was non-significant stenosis which was designed by normal or stenosis less than 50%. The site having blooming artifact due to calcification that causes complete obliteration of the lumen or having significant motional artifacts was ruled out. There were 285 evaluable sites in 19 patients with high heart rates, more than 70 beats/ minute. The sensitivity, specificity, and accuracy in significant stenosis were 72.9%, 99.6%, and 94.0% respectively. In 36 patients with a lower heart rate, there were 563 evaluable sites, the sensitivity was 86.5%, specificity was 98.5%, and accuracy was 96.6%. The overall showed 81.1% of sensitivity, 98.9% of specificity, and 95.8% of accuracy.
Conclusion: The accuracy of the 16-slice CT angiography for patients suspected of having coronary artery disease was high. However, blooming artifacts from the calcium, respiratory artifacts, and small size of the distal and branching artery still caused limited luminal assessment. These problems have challenged the new coming generation of MDCT.

Keywords: CT angiography, Coronary angiography, Coronary disease