双源CT双能量心肌灌注成像的图像质量及辐射剂量研究

目的：探讨运用双源CT双能量技术行冠状动脉血管成像的图像质量和辐射剂量。方法：204例患者分为两组行双源CT冠状动脉血管造影检查,A组采用双能量扫描方案,B组采用传统单能量扫描方案,比较两组的图像质量及辐射剂量。结果：A、B两组冠状动脉图像质量评分分别为（4.70±0.72）分、（4.70±0.71）分,两组间差异无统计学意义（t=-1.000,P=0.318）。A、B两组图像左、右冠状动脉信噪比（SNR）分别为A组20.0±3.4和19.0±3.0、B组20.1±3.2和19.9±3.2,且两组间差异均无统计学意义（t=1.967,P=0.051;t=-0.233,P=0.816）。A、B两组的容积CT剂量指数（CTDIvol）、剂量长度乘积（DLP）、有效辐射剂量（ED）分别为（48.27±8.70）mGy、（54.10±8.77）mGy;（565.63±115.48）mGy.cm、（702.75±144.04）mGy.cm;（9.62±1.96）mSv、（11.95±2.45）mSv,A组的CTDIvol、DLP及ED明显低于B组,差异均有统计学意义（t=-4.764,P=0.000;t=-7.501,P=0.000;t=-7.501,P=0.000）。结论：双能量心肌灌注成像技术在不降低图像质量的情况下,能够显著降低患者的有效辐射剂量,有很高的临床应用价值。

Study of image quality and radiation dose with dual-energy technique in myocardial perfusion imaging using dual-source CT

Objective：To investigate the image quality and radiation dose of dual-energy technique for myocardial perfusion imaging with dual source CT.Methods：204 patients undergone coronary CT angiography（CTA） were divided into two groups,group A with dual energy CT and group B with single-energy scanning protocol respectively.The radiation dose and image quality of these two groups were compared.Results：The image quality scores of coronary artery for group A and group B were 4.70±0.72 and 4.70±0.71,respectively,with no statistic difference（t=-1.000,P=0.318）.The signal noise ratio（SNR） of left and right coronary artery in group A and group B were 20.0±3.4,19.0±3.0 and 20.1±3.2,19.9±3.2 respectively,with no statistic difference（t=-0.233,1.967,P=0.816,0.051）.The CT dose index of volume（CTDIvol）,dose length product（DLP） and effective dose（ED） were（48.27±8.70）mGy,（565.63±115.48）mGy·cm,（9.62±1.96）mSv respectively for group A and（54.10±8.77）mGy,（702.75±144.04）mGy·cm,（11.95±2.45）mSv respectively for group B.The CTDI vol and ED of group A were obviously lesser than that of group B,with significant statistic difference（t=-4.764,P=0.000;t=-7.501,P=0.000;t=-7.501,P=0.000）.Conclusion：Using the dual-energy technique with dual source CT for myocardial perfusion imaging can obviously reduce the radiation dose while with no influence on image quality,which provides great potential in clinical application.