Diagnostic Accuracy of Noninvasive Coronary Angiography Using 64-Slice Spiral Computed Tomography

Introduction: The aim of our study was evaluation the diagnostic accuracy of multislice computed tomo-graphy (MSCT) coronary angiography using a 64-slicescanner. The 64-slice MSCT scanner has im-proved spatial resolution and a faster rotation time (0.33 s) compared to prior 16 and 32-slice scanners. Materials and methods: We studied the results of 64-slice MSCT coronary angiography (CTA), with elec-tive invasive coronary angiography, in 50 patients. The mean time span between invasive coronary an-giography (ICAG) and CTA was 6 days. Patients with atrial fibrillation, high heart rate (>80), contraindications to blockers, drugs and patients at risk for iodinated contrast agents. Were excluded All vessels were analyzed, including those >1.5 mm in diameter; MSCT lesions were analyzed quantitatively as well as by a qualitative scale and compared to quantitative coronary angiography. Results were also analyzed for significant coronary stenosis (over 50% luminal narrowing) by segment, artery, and patient. Results: Of 942 segments, 856 (91%) were assessable. 25% of patients had calcium scores above 400 Agat-ston U, 25% had heart rates of 70-80 beats/min, and 50% were obese. CTA in comparison with ICAG, the sensitivity of CTA for diagnosis of significant stenosis was 90%, specificity was 94%, positive predictive value (PPV) and negative predictive value (NPV) were %89 and %95, respectively.. Regarding to 10 stented lesions, the sensitivity, specificity, PPV and NPV were 93%, 96%, 87% and 98%, respectively. On the patient-based analysis, the sensitivity, specificity, PPV and NPV of CTA to detect coronary artery dis-ease were 98%, 86%, 98% and 86%, respectively. 86 (9%) segments were not assessable because of sever calcification, irregular rhythm or tachycardia. Conclusion: 64-MSCT has high accuracy for the de-tection of significant coronary artery disease and therefore can be considered as a valuable noninvasive technique.