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目的:探讨16层螺旋CT冠状动脉血管成像技术。方法:272例受检者行16层螺旋CT冠状动脉血管成像检查,采用电影扫描序列,层厚为1.25mm或0.625mm,螺距为0.275:1,对比剂1.5~2ml/kg,注射速率3~4ml/s,采用容积再现(VR)、多平面重建(MPR)、曲面重建(CPR)和仿真内窥镜(VE)进行图像后处理重建,显示冠状动脉主干及其主要分支。结果:心率对图像质量的影响较大(χ2=23.936,P<0.01),心率平稳,心率在55~75次/min,MSCT对冠状动脉主干及主要分支显示率80.3%达到诊断要求,心率大于90次/分时,冠状动脉的主要分支显示不清;重建相位窗在55%、65%和75%之间显示一、二级高质量冠状动脉图像的例数无显著性差异(χ2=1.980,P>0.05),选择重建相位窗为75%可提高工作效率;采用扫描层厚为0.625mm或1.25mm(重建间隔为0.625)所得到的图像质量可满足影像及临床诊断需要(χ2=0.833,P>0.05),选择扫描层厚1.25mm所获得图像的信噪比及移动伪影明显减少;采用3.5ml/s或4ml/s注射速率图像重建后达到一、二级水平的图像质量基本接近(χ2=0.268,P>0.05),使用注射速率为3.5ml/s,显示冠状动脉清晰且受腔静脉伪影少。结论:心率平稳且小于75次/min,使用合适的重建相位窗、对比剂及扫描参数,MSCT可满意显示冠状动脉主干及主要分支,可作为冠状动脉粥样硬化疾患的筛选,对血管搭桥和内支架放置术后复查的评价有较高临床价值。
Objective: To explore 16-slice spiral CT coronary angiography. Methods: A total of 272 subjects underwent 16 - slice spiral CT coronary angiography. The film thickness was 1.25mm or 0.625mm, the pitch was 0.275: 1, the contrast agent was 1.5-2ml / kg and the injection rate was 3 ~ 4ml / s. The images were reconstructed using Volume Reproduction (VR), Multiplanar Reconstruction (MPR), Surface Reconstruction (CPR) and Virtual Endoscopy (VE) to reveal the main coronary artery and its major branches. Results: The heart rate had a significant effect on the image quality (χ2 = 23.936, P <0.01). The heart rate was stable and the heart rate ranged from 55 to 75 beats / min. MSCT showed the diagnosis rate of 80.3% for the main coronary artery and the main branch, At 90 beats / min, the major branches of the coronary arteries were unclear; reconstruction of the phase window showed no significant difference in the number of first and second grade high quality coronary arteries at 55%, 65%, and 75% (χ2 = 1.980 , P> 0.05). Choosing reconstructed phase window of 75% could improve the working efficiency. The image quality obtained by using scan slice thickness of 0.625mm or 1.25mm (reconstruction interval of 0.625) can meet the needs of imaging and clinical diagnosis (χ2 = 0.833 , P> 0.05). The signal-to-noise ratio (SNR) and motion artifact of the images obtained by scanning layer thickness 1.25mm were significantly reduced. The image quality reached the first and the second level after 3.5ml / s or 4ml / s injection rate reconstruction Close to (χ2 = 0.268, P> 0.05), the injection rate was 3.5ml / s, showing a clear coronary artery and less vena cava artifacts. CONCLUSIONS: The heart rate is stable and less than 75 beats / min. MSCT can satisfactorily display the main coronary artery and its major branches using suitable reconstructed phase windows, contrast agents and scanning parameters. It can be used as a screening tool for coronary atherosclerosis, Evaluation of postoperative stent placement has high clinical value.