心电门控技术对双源CT大螺距扫描辐射剂量影响的模体研究OA

Objective:To investigate the variations in radiation dose during dual-source computed tomography(CT)high pitch spiral scanning with and without electrocardiogram(ECG)gating.Materials and Methods:A phantom was scanned using dual-source CT.Scanning was performed with ECG gating and non-ECG gating techniques under automatic exposure control and non-automatic exposure control,using the same reference voltage of 100 kV and reference amperages(ECG gating group 400,480,and 560 mAs/rot;non-ECG gating group 125,150,and 175 mAs).The variations in radiation dose and image noise were measured.Results:Under automatic exposure control,the radiation doses of the ECG gating group(400,480,and 560 mAs/rot)and the non-ECG gating group(125,150,and 175 mAs)were not equal;fully automatic tube voltage modulation,t=-6.247,P<0.05;semi-automatic:t=-6.247,P<0.05;and closed:t=-9.475,P<0.05.There were also differences in the image noise.Under non-automatic exposure control,the radiation doses of the ECG gating group(400,480,and 560 mAs/rot)and the non-ECG gating group(125,150,and 175 mAs)were equal(t=1.250,P=0.338),and the image noise was equal.Conclusion:Under automatic exposure control,the radiation doses and image noise of ECG gating and non-ECG gating were not equal but under non-automatic exposure control,they were equal.