64排VCT XT冠脉低剂量扫描技术对诊断效果的影响

目的：评价64排VCT XT冠状动脉成像中前门控点射式轴位扫描对图像质量的影响及应用价值，探讨低剂量CCTA检查的临床应用效果。方法：筛选100例行冠脉前瞻性门控轴位扫描的患者，根据患者体重指数（body mass index．BMI）选择管电流为180～800mA，管电压为100～120kV。记录扫描中患者所受射线剂量，并将其与回顾性门控扫描参数进行模拟计算剂量对比，采用SPSS10．0软件对其图像质量进行对比评价（5分优，1分差）。结果：在相同管电压条件下，前门控射线剂量（平均2．27msv）远远低于回顾性心电门控（平均14．15msv）。两种扫描方式下，图像质量和诊断效果没有显著性差异。结论：64排VCT XT采用的前门控扫描技术及个性化的扫描参数，能够在大大降低射线剂量（至少75％）的同时获得满足临床诊断需要的图像质量及诊断效果。

Effects of Diagnosis of GE Light Speed 64-row VCT XT Coronary Scanning Technology with Low Ray Dose

Objective To discuss the effects of diagnosis of GE light speed 64-row VCT XT coronary scanning technology with low ray dose. Methods 100 patients of coronary imaging were selected for forward-looking gated axial scanning and choices tube electric current 180 -800 mA based on body mass index（BMI） of patients, and the tube voltage was from 100 kV to 120 kV. The ray dose of patients in scanning was registered and evaluates the image quafity（5 excellent, 1 bad）by using SPSS10.0. Results The image quality can be satisfactory when use fixed fire-controlled exposure mode CTA scanning the front door in a stable heart rate below 70 bpm. With compared to retrospective ECG-gated, the two scanning modes effects and diagnostic image quality had no significant difference. Conclusion The 64-row VCT XT can significantly reduce radiation dose （at least 75%）, at the same time guarantee retrospective ECG-gated coronary CTA scanning receiving the same image quality and diagnostic effects, and its image quality can meet the needs of the clinical diagnosis.