64层CT与冠状动脉造影在老年冠心病诊断中的对比研究

Comparative study between 64-slice CT and CAG for evaluating coronary artery stenosis

目的评价64层CT与冠状动脉造影在老年冠心病诊断中的价值。方法70例疑似和确诊的冠心病患者进行64层田检查，男性45例，女性25例，平均年龄（69．97±9．75）岁，其中50例与冠状动脉造影比较，冠状动脉狭窄〉50％。包括曾行冠状动脉旁路移植术5例、冠状动脉内支架置入术10例。平均心率（68．31±6．26）次／min，37例服用美托洛尔12．5～25mg。64层田检查与冠状动脉造影检查间隔1—15天。结果50例患者共分析了739个血管节段，200支血管，单支血管病变11例，双支血管病变26例，3支血管病变21例，40例有钙沉积。其中，轻中度钙化（〈400分）21例，重度钙化（≥400分）19例。冠状动脉轻度狭窄（≥50％或不规则狭窄）38个节段，中度狭窄（70％～90％）44个节段，重度狭窄（≥90％）44个节段，完全闭塞7个节段。冠状动脉造影7例阴性者，64层田完全符合。影响诊断因素的3例4个节段因心率〉80次／min、呼吸配合不佳出现伪影，4例7个节段严重钙化影响狭窄的判断。敏感性91．7％，特异性97．5％，阳性相关率96．1％，阴性相关率98．6％。结论64层CT可以作为老年冠心病无创检查和治疗初筛的可靠方法。

Objective To prospectively evaluate the accuracy of new 64-slice computed tomography （CT） in comparison with invasive coronary angiography （ICA） for visualizing atherosclerosis in the coronary system. Methods Seventy consecutive patients （mean age 69.97 ± 9.75） with suspected coronary artery disease were investigated. All patients underwent both 64-slice CT and ICA no more than 15 days apart. CT images were interpreted at computer workstations in a blinded fashion. One radiologist independently reviewed the CT images, and another cardiologist independently reviewed the ICA images. All vessels ≥ 1.5 mm in diameter were considered for the assessment of significant coronary artery stenosis （decrease in diameter 〉 50 % ）. The coronary arteries were segmented according to the guidelines of the American Heart Association. Sensitivity, specificity, the positive and negative predictive values were deter mined independently for image interpretation performed by the CT image reader and the ICA image reader by using the ICA reader＇s interpretation as the reference standard. Results A total of 133 stenosis were detected at ICA in the 70 patients, with 7.60 % of them being complete vessel occlusion. CT image quality was rated as excellent in 78 %, good in 17%, and adequate in 5 %. No vessel segment had to be excluded from analysis. Sensitivity, specificity, positive predictive value and negative predictive value for CT angiography were 91.7%, 97.5%, 96.1% and 98.6% respectively. Conclusion Sixty-four-slice CT has high sensitivity and specificity for detection of coronary artery stenosis. Compared with ICA, it is not only noninvasive, easy to perform, reproducible, readily available and accompanied by minimal complications, but also can depict aneurysms with a high degree of accuracy.