الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Coronary artery disease is one of the treatable causes of mortality and morbidity, both in developed as well as developing countries. A non-invasive method that would allow the evaluation of coronary stenosis with a comparable accuracy to catheter based angiography would have enormous clinical value. Non-invasive imaging of the coronary arteries is faced with great difficulties. Most obviously, coronary vessels have small dimensions, which require high spatial resolution. Also, they are subjected to rapid motion because of cardiac contraction. Sufficient temporal resolution is thus necessary to avoid artifacts (Achenbach S., 2007).
State-of-the-art multi-slice CT machines with higher and developing spatial and temporal resolution allow a noninvasive approach to accurately delineate coronary artery anatomic structures (Diaz-Zamudio et al.,2009).
Several newer generation CT scanners are now available. With increasingly more detector rows and higher gantry speeds, allowing for better visualization of the coronary arteries (Diaz-Zamudio et al.,2009).
The aim of our study was to assess the diagnostic accuracy of multi-slice Ct coronary angiography (MSCT) for detection of significant coronary lesion when compared to quantitative coronary angiography (QCA).
100 male patients with mean age 58 ± 8 years whose ages ranging from 45 to 73 years old were consecutively included into our study. Patients included into the study who had class II angina according to The Canadian Cardiovascular Society (CCS), presented with different symptoms as dyspnea, chest pain and palpitation, underwent MSCT coronary angiography and then elective invasive coronary angiography was performed for patients who had coronary arterial stenosis on MSCT angiography within 15-30 days of MSCT coronary angiography.
Scans of coronary CTA and catheter angiography were analyzed by two observers unaware of the clinical data. If there was a disagreement related to the severity of stenosis of a certain coronary segment, a third opinion was taken to reach a final agreement. The results of CCTA were compared to QCA according to per-artery analysis, examining the presence of significant lesions in each of the major coronary vessels (Left Main, Left anterior descending & diagonal branch, Left circumflex & obtuse marginal and Right coronary artery). Each arterial lesion was described according to severity of stenosis as:
Mild stenosis (less than 50% of the vessel lumen).
Moderate stenosis (50% up to 69% of the vessel lumen).
Severe stenosis (70% or greater of the vessel lumen).
Our study showed that Dual 64 slice CT coronary angiography had a sensitivity of 97.7%, specificity of 97.9%, positive predictive value of 92.8% and negative predictive value of 99.3% for detecting stenosis 50% or greater and also had a sensitivity of 94.7%, specificity of 96.8%, positive predictive value of 86.5% and negative predictive value of 99.3% for detecting stenosis 70% or greater. The high negative predictive value (99.3%) can be utilized to rule out coronary artery disease in the clinical scenarios before sending the patients to invasive coronary angiography and this would minimize the burden and optimize the hospital performance and minimize the unnecessary risk in a substantial number of patients who would have been otherwise sent to invasive coronary angiography.