双源CT冠状动脉成像的影响因素及处理技巧

Factors Influencing Image Quality of Dual Source CT Cornary Angiography and Their Management

目的:探讨双源CT冠脉成像的影响因素及处理技巧。方法:180例患者行双源CT冠脉成像,并采用MPR,MIP及VRT等技术进行图像后处理,根据国际冠状动脉分段标准,并按照优、良、中、差4个等级评价冠脉成像质量,分析影响冠脉成像质量的相关因素及处理方法。结果:180例患者共评价2575个血管节段,优质血管影像达65.2%(1679段),良达25.3%(651段),中达7.3%(188段),差为2.2%(57段);双源CT冠脉成像优良率达90.5%,不可评价率2.2%。主要影响因素有心率波动(106段)、呼吸屏气不良(52段)、对比剂因素(51段),成像参数的选择(35)等。对因心率波动所致图像质量不佳的106个血管节段进行心电编辑处理后,图像质量不佳者减少至53段(50%),且图像无法评价的节段由38段减少至15段(60.5%)。结论:双源CT冠脉成像质量较好,但仍受一些因素影响,仔细的检查前准备、采用心电编辑技术等能有效提高成像质量。

Objective：To study the factors influencing image quality of coronary angiography with dual source CT and the techniques of management. Methods： 180 cases had cornary angiography with dual-source CT, the post-processing techniques included multi planar reformation （MPR）, maximal intensity projection （MIP） and virtual rendering technique （VRT）. The subdivisions of coronary arteries were classified according to international classification of cornary artery sections. The quality of coronary angiography was divided into four grades： excellent,good, fair and poor. The influencing factors of image quality and their management techniques were analyzed. Results： Of the 180 patients with coronary angiography,altogether there were 2575 sections of coronary arteries. As for the gradation of image quality,65.2M （1679 sections） were excellent,25.3% （651 sections） were good,7.3% （188 sections） were fair and 2.2% （57 sections） were poor. High image quality of coronary angiography with dual source CT reached 90.5%. There were 2.2% with the images unreadable. The main factors that influenced image quality were fluctuation of heart beat （106 sections）, uncontrolled breath-holding （52 sections） ,influence due to contrast medium （51 sections） and selection of imaging parameters （35 sections）. For the 106 sections of coronary arteries with fair or poor image quality due to fluctuation of heart beat,the fair or poor quality images reduced to 53 sections （50 %） after ECG editing during image reconstruction. For the 38 unreadable sections,they were reduced to 15 sections （60.5%） after ECG editing. Conclusion： High image quality of coronary angiography could he obtained with dual source CT. There are some factors influencing the image quality, which could be improved by exquisite preparation before examination and ECG editing during image reconstruction.