64排螺旋CT冠状动脉成像时主动脉根部与冠状动脉强化值及噪声值的相关性研究

The Relationship Between Aorta Root and Coronary Artery Enhancement and Noise at 64-Row MSCT Coronary Angiography

目的 探讨主动脉根部与冠状动脉的强化值（CT值）及噪声值（SD值）的相关性.方法 对100例冠状动脉CT成像患者进行回顾性分析.分别测量主动脉根部、左冠状动脉主干、右冠状动脉、左前降支和左回旋支近端血管腔的CT值和 SD值,主动脉根部感兴趣区（ROI）面积设定为1.0mm2和100mm2,冠状动脉ROI面积为1.0mm2,连续测量3个感兴趣区,计算平均值和信噪比（SNR）.结果 当主动脉根部ROI=1.0mm2时,主动脉根部与冠状动脉CT值、SD值及SNR均呈线性高度相关,相关系数分别为0.85、0.77、0.76.当主动脉根部ROI=100mm2时,主动脉根部与冠状动脉CT值呈线性高度相关 （r=0.82）,SD值呈线性中度相关（r=0.47）,SNR呈线性低度相关（r=0.34）.结论 ROI面积相同时,主动脉根部SD值及SNR能反映冠状动脉成像的图像质量;ROI面积不同时,二者相关性较低.

Objective To analysis the relationship between aorta root and coronary artery enhancement（CT value） and noise（SD value）.Methods To retrospectively analysis 100 patients underwent coronary angiography.We measure the CT value and SD value of aorta root, left coronary artery, right coronary artery, left anterior descending branch,left circumflex branch.The region of interest（ROI） of aorta root were 1.0mm2 and 100mm2,the ROI of coronary artery was 1.0mm2,select three ROI consecutively.Calculate the mean value and SNR.Results When ROI of aorta root was 1.0mm2,the CT value,SD value and SNR between aorta root and coronary artery were high linear correlation,the correlation coefficient is 0.85,0.77,0.76 respectively.When ROI of aorta root was 100mm2,the CT value between aorta root and coronary artery was high linear correlation（r=0.82）,SD value is midrange linear correlationQ-=0.47）,SNR is low linear correlation（r=0.34）.Conclusions When ROI is same,the SD value and SNR of aorta root can reflect image quality of CTCA well.When ROI is different,the linear correlation coefficient was low.