Clinical Investigation Of Diagnasis Of Coronary Artery Stenoses And Calcification And Plaque Texture By 64-slice Spiral CT

Objectives To evaluate the accurary in diagnosis of coronary artery stenoses and the clinical values of coronary artery calcification plaque by 64-slice spiral computed tomography(64SCT) in contrast to selective coronary angiography(SCA).Methods 31 patients with acute coronary syndrome (ACS)(including unstable angina pectoris and acute myocardial infarction), 22 patients with stable angina pectoris (SA) on the basis of the electrocardiographic (ECG) and cardiac enzyme concentrations and 20 patients without coronary heart disease (CHD) by selective coronary angiography served as control subjects.All patients underwent both 64-slice computed tomography coronary angiography (64SCTA) and selective coronary angiography with an interval of two weeks. A bolus of contrast media was injected into an antecubital vein. The total amount of the contrast media was 70-80ml and the contrast injection speed was 4.0ml/s.The start delay was automatically difined using the bolus tracking software included in the scanner. The region of interest was placed within the ascending aorta and the scan was started when the computed tomography (CT) density was 120 Hounsfield units higher than the baseline CT density. Using various advanced post-processing function of 64SCT to reconstruct coronary artery,demonstrated the main branches and analyzed. Then calculated coronary artery calcium score ,diagnosed plaque and classified calcify plaque, middle plaque and flexible plaque.CTA image quality was evaluated in 9 coronary segments by two experienced radiologists in concensus. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for detection of significant stenosis (>50%) on a segmental basis using SCA as reference and gold standard.Rusults 1.64SCTA detected no significant coronary stenosis (>50%) in 12 control subjects, which was accorded with the results of selective coronary angiography. 2.The sensitivity,specificity,positive and negative predictive value to identify coronary significant stenosis (>50%) in 31 patients with ACS and 22 patients with SA were 95.12%,98.25%,90.70%, 99.12% and 94.83%,95.42%,90.16%,97.66% respectively. 3.The rate of coronary artery calcification and plaque were different among patients with ACS ,SA and normals (p<0.05).Conclusions 1.64SCT can display coronary artery images clearly ,and can be a potential, noninvasive examination method for excluding coronary heart disease in patients without typical precordial chest pain symptoms. 2.64SCT had high sensitivity and negative predictive value for detection of coronary significant stenosis,and will be a potential, noninvasive method for diagnosing coronary artery disease. 3.64SCT can calculated coronary artery calcium score ,which is helpful for CHD,and can detect coronary artery plaque texture and predict coronary events in clinical practice.