【摘要】 目的采用256iCT进行冠状动脉CTA(CCTA),并联合多种技术优化扫描方案以降低辐射剂量。方法纳入91例接受256iCT CCTA(研究组)和30例接受64排CCTA(对照组)的可疑冠状动脉粥样硬化性心脏病患者。研究组根据患者心率设置6种扫描方案,方案1采用前瞻性心电门控技术,启动z轴方向自动管电流调节技术,方案2、3采用回顾性心电门控技术+ECG电流调控(ECG-CTCM)技术,方案4~6采用回顾性心电门控技术,各扫描方案均根据BMI设置管电压。计算并比较各组及各扫描方案间有效剂量(ED)和图像质量评分差异。结果研究组ED[(12.78±5.87)mSv]明显低于对照组[(19.49±1.65)mSv,P<0.05]。研究组扫描方案1ED最低,其次为扫描方案3,两种扫描方案ED均明显低于其余扫描方案(P均<0.05),二者间差异亦有统计学意义(P<0.05),扫描方案2、4~6两两比较差异均无统计学意义(P均>0.05);各扫描方案中ED均随管电压下降而下降。各扫描方案间图像质量评分差异无统计学意义(F=0.610,P=0.858)。结论 CCTA中256iCT辐射剂量低于64排螺旋CT;前瞻性心电门控技术、ECG电流调控技术和个体化扫描均可不同程度降低辐射剂量,并不影响图像质量。更多还原

【Abstract】 Objective To optimize the scanning protocol for reducing radiation dose through combining various techniques in coronary CTA(CCTA)by using 256 iCT.Methods Totally 91 cases receiving 256 iCT CCTA(research group)and 30 cases receiving 64-slice CCTA(control group)who were suspected coronary disease were enrolled.In research group,six scanning protocols were applied based on the heart rate,i.e.protocol 1used prospectively ECG-gated technique combined with automatic tube current modulation(ATCM),protocol 2and 3used restrospectively ECG-gated technique combined with ECG-controlled tube current modulation(ECG-CTCM),protocal 4—6used restrospectively ECG-gated technique.The tube voltage was set according to the BMI.The effective dose(ED)and image qualitiy score of each group and protocol was calculated and compared.Results ED of research group was obviously lower than that of control group([12.78±5.87]vs[19.49±1.65]mSv,P<0.05).In research group ED of protocal 1was the lowest,followed by protocal 3(P<0.05),both significantly lower than that of protocal 2and 4—6(all P<0.05).ED of protocal 2and 4—6had no significantly differences(all P>0.05).ED was reduced along with the tube voltage in all the protocal.Image quality score showed no differences among different scanning protocals(F=0.610,P=0.858).Conclusion In CCTA,radiation dose was lower by using 256 iCT compared with 64-slice CT,which can be reduced through prospectively ECG-gated,ECGCTCM and individualized scanning without impacting the image quality.更多还原