320排容积CT冠状静脉对比剂浓度对评价冠状动脉狭窄的影响

Influence of Contrast Media Concentration in Coronary Vein with 320-detector Volume CT Angiography for Evaluating Coronary Artery Stenosis

目的 探讨冠状动脉CT血管成像（CCTA）冠状静脉轻度对比剂显影对获取冠状动脉显影最佳时相的重要性.资料与方法 提取198例行冠状动脉造影患者的CCTA影像资料,根据CCTA原始图像冠状静脉CT值分成A组（0～50 Hu）98例和B组（51～100 Hu） 100例,比较两组冠状动脉近中段及远段图像质量差异.以冠状动脉造影为“金标准”对管腔狭窄≥50％的冠状动脉血管进行分析,评价两组CCTA诊断冠状动脉狭窄的敏感度、特异度、准确度、阳性预测值、阴性预测值.结果 A组与B组血管平均CT值、信噪比及图像质量评分差异无统计学意义（t=1.32、2.19、-1.432,P＞0.05）.A组与B组CCTA诊断冠状动脉狭窄的敏感度分别为88％和92％,特异度分别为75％和84％,准确度分别为81％和88％,阳性预测值分别为76％和87％,阴性预测值分别为87％和89％,B组的诊断效能优于A组.结论 CCTA检查冠状静脉内适当浓度对比剂是判断其最佳扫描时相的重要指标之一.对于狭窄≥50％的冠状动脉,冠状静脉内合适的对比剂强化可以改善冠状动脉狭窄的诊断准确性.

Purpose To investigate the influence of mild contrast enhancement in coronary vein in coronary CT angiography （CCTA） for obtaining the best imaging phase of coronary artery.Materials and Mathods A total of 198 patients who had underwent coronary angiography were enrolled and divided into two groups according to the CT value of coronary vein：group A （0-50 Hu） including 98 cases; group B （51-100 Hu） including 100 cases,differences of the image quality of the corresponding proximal middle and distal coronary artery between the two groups were retrospectively compared.With the result of coronary angiography as the reference ＂gold standard＂,coronary arteries with stenosis of 50％ or more were statistically analyzed,sensitivity,specificity,accuracy,positive predictive value,negative predictive value of the two CCTA groups were evaluated.Results There was no significant difference between the two groups in mean CT value,SNR and image quality score of coronary arteries （t =1.32,2.19 and-1.432,P＞0.05）.For the diagnosis of coronary artery stenosis,the sensitivity,specificity,accuracy,positive predictive value and negative predictive value of CCTA in group A and group B were 88％ and 92％,75％ and 84％,81％ and 88％,76％ and 87％,87％ and 89％,respectively,with the diagnostic efficiency of group B superior to that of group A.Conclusion The proper contrast enhancement in the coronary vein is one of the important aspects to determine the optimal scanning time of CCTA.For the coronary artery with stenosis of 50％ or more,the proper enhancement in coronary vein can improve the accuracy of CCTA.