64排VCT XT前瞻性心电门控低剂量技术对冠状动脉成像的研究

目的：评价64排VCTXT前瞻性心电门控低剂量技术对冠状动脉成像的能力及图像质量分析。方法：连续选取152例行冠状动脉CTA检查的患者（A组平均体重指数25.1,心率〈65次/min）行前门控扫描,根据患者的自动毫安量选择管电流及管电压。同时比较回归性心电门控螺旋扫描的30例患者（B组平均体重指数25.7,心率〈72次/min）的剂量,并对两组图像质量进行评价（配对t检验,P〈0.005为差异有统计学意义）。结果：A组前瞻性门控横断面扫描冠状动脉成像射线剂量平均为（2.75±0.95）mSv,所获图像质量完全达到临床诊断需要,B组回顾性心电门控螺旋扫描冠状动脉成像平均剂量为（18.2±2.9）mSv。B组与A组比较差异有统计学意义,射线剂量减少了85.2%。结论：64排VCTXT前瞻性心电门控技术横断面扫描能满足临床诊断需要,同时也非常有效的降低了辐射剂量。

Study of dose reduction using prospective electrocardiography-triggered coronary scan with 64-slice VCT XT

Objective To compare radiation dose and image quality between prospective electocardiograph-triggered axial scan and retrospective ECG-gatechelical scan in coronary 64-slice CT angiography(CTA).Method Total 152 consecutive patients:group A:Average body mass index(BMI):25.1,heart rate< 65 bpm underwent 64-slice CTA.Using prospective ECG-triggered axial scan protal(120kV automA preference);group B:Average body mass index(BMI):25.7,heart rate<72 bpm.The image quality was blindly evaluated between group A and group B(paired test was used and P<0.05 as a significant difference).Results There was significant difference(t=18.5,P<0.01) between radiation dose of group A[(2.75±0.95) mSv] and that of group B [(18.2±2.9) mSv],decreased by 85.2%.The image quality of group A could fulfill clinical diagnosis needs.The average radiation dose of using helical scan without optimization was 17.29 mSv which was similar to that of group B(18.13 mSv).Conclusion Prospetive ECG-trigered axial scan in 64-slice coronary CTA can significantly reduce radiation exposure and the image quality can fulfill clinical diagnosis needs.