SSF技术在CT冠状动脉成像中的应用

目的探讨冠状动脉追踪冻结技术(snapshot freeze,SSF)在CT冠状动脉成像中的应用价值。方法收集69例疑似冠心病患者行CT冠状动脉成像检查,从45%和75%期相中选择最佳期相的图像分别重建为标准方法组和SSF方法组;采取双盲法由两位高年资医师按照冠状动脉15段分段法,使用5分制评分法评价两组图像质量;分别测量出两组图像中右冠状动脉中段血管横断面移动伪影区域以及邻近脂肪组织的标准偏差(SD)值,计算移动伪影指数(moving artifact index,MAI)值。应用配对样本的t检验对两组图像的图像质量和MAI值进行比较,应用2检验比较两组图像冠状动脉分级显示段数。结果69例患者875段冠状动脉节段被评价,在使用SSF方法重建后图像质量主观评分高于标准方法组,差异有统计学意义(P均<0.05);而左主干两组图像质量比较,改善不明显,差异无统计学意义(P>0.05)。移动伪影指数(MAI)标准方法组高于SSF方法组,差异有统计学意义(P<0.05)。结论CT冠状动脉成像中,SSF技术可减轻移动伪影,改善图像质量,具有较好的应用价值。

The application of SSF to CT coronary angiography

Objective To explore application value of coronary artery tracking snapshot freeze(SSF)in CT coronary angiography.Methods 69 suspected coronary artery disease patients underwent CT coronary angiography.The best phase images were selected from 45%phase and 75%phase to reconstruct standard group and SSF group,respectively.The image quality of the two groups was evaluated on a scale of 0~5 points using a double-blind method by two senior attending physicians with method of 15-segmentation of coronary artery.After this,the following parts were calculated:the moving artifact area of transverse section of the middle part of right coronary artery,standard deviation(SD)value of adjacent adipose tissue,and the moving artifact index.The image quality and MAI value of these 2 groups were compared using t test of paired samples;the number of segments on graded display of coronary artery of two images were compared using 2 test.Results 875 segments of coronary artery from 69 patients were evaluated.After the reconstruction using SSF,subjective score of image quality was higher than that of standard method group(P<0.05),and the difference was statistically meaningful.There was no clear difference in the quality of 2 groups’images of left main artery group(P>0.05),and this difference was not statistically meaningful.The Moving artifact index(MAI)standard method group was higher than SSF method group,and the difference was statistically meaningful(P<0.05).Conclusion SSF technology can reduce the moving artifacts and improve the image quality in CT coronary angiography,which is of promising application value.