OBJECTIVES We sought to compare the diagnostic value of multi-slice computed tomography (MSCT) coronary angiography (CA) to detect significant stenoses (greater than or equal to50% lumen diameter reduction) with that of invasive CA. BACKGROUND The latest 16-row MSCT scanner has a faster rotation time (375 ms) and permits scanning with a higher X-ray tube current (500 to 600 mA) during MSCT CA when compared with previous scanners. METHODS We studied 51 patients (37 men, mean age 58.9 +/- 10.0 years) with stable angina or atypical chest pain. Patients with pre-scan heart rates greater than or equal to70 beats/min received oral beta-blockade. The heart was scanned after intravenous injection of 100 ml contrast (iodine content, 400 mg/ml). Mean scan time was 18.9 +/- 1.0 s. The MSCT scans were analyzed by two observers unaware of the results of invasive angiography, and all available coronary branches greater than or equal to2 mm were included. RESULTS Invasive CA demonstrated normal arteries in 16% (8 of 51), non-significant disease in 21% (11 of 51), single-vessel disease in 37% (19 of 51), and multi-vessel disease in 26% (13 of 51) of patients. There were 64 significant lesions. Sensitivity, specificity, and positive and negative predictive values for detection of significant lesions on a segment-based analysis were 95% (61 of 64, 95% corifidence interval [CI] 86 to 99), 98% (537 of 546, 95% CI 96 to 99), 87% (61 of 70, 95% CI 76 to 98), and 99% (537 of 540, 95% CI 98 to 99), respectively. All patients with angiographically normal coronary arteries or significant lesions were correctly identified. Three of 11 patients with <50% lesions were incorrectly classified as having single-vessel disease. CONCLUSIONS The 16-row MSCT CA reliably detects significant coronary stenoses in patients with atypical chest pain or stable angina pectoris. (C) 2005 by the American College of Cardiology Foundation.