炫速双源CT冠脉成像的辐射剂量优化与胸廓径线的关系

The Correlation of Image Quality Adapted and Thoracic Diameters in Somatom Definition Flash Dual Source CT Coronary Artery Imaging

目的:探讨西门子Somatom Definition Flash炫速双源CT冠脉成像的辐射剂量优化与胸廓径线的关系。方法:以笔者所在医院2014年6-12月经Somatom Definition Flash炫速双源CT冠脉成像检查的52例患者为研究对象,根据患者的体质指数BMI分为A、B两组:A组患者(BMI<25 kg/m2)29例,扫描参数为管电压120 k V,管电流220 m As。B组患者(25 kg/m2≤BMI<30 kg/m2)23例,扫描参数为管电压120 k V,管电流330 m As。计算冠脉相对于背脊肌的对比噪声比(CNR)、信噪比(SNR)。对CNR和SNR与胸廓径线、BMI的相关性进行检验。结果:A、B两组患者胸廓AP、RL径线均与CNR具有相关性(P<0.05)。A、B两组患者CNR、SNR与RL径线的相关系数均大于CNR、SNR与AP径线的相关系数。除A组第2层面外,CNR与AP径线的相关系数均大于其与BMI的相关系数。结论:胸廓径线可以指导Somatom Definition Flash炫速双源CT冠脉成像的辐射剂量。

Objective：To evaluate the correlation between image quality and thoracic diameters.Method：The clinical data of 52 patients which checked by Somatom Definition Flash dual source CT were divided into two group according to body mass index（BMI）.There were 29 patients in group A with BMI values 25 kg/m2,CT images were obtained tube voltage 120 k V,tube current 220 m As;and 23 patients in group B with BMI values ≥ 25 kg/m2 and 30 kg/m2.CT images were obtained tube voltage 120 k V,tube current 330 m As.The contrast noise ratio（CNR）,signal to noise ratio（SNR）,as well as blind correlation test score values were calculated to establish the relationship among BMI,AP,RL and CNR,SNR.Result：AP,RL in group A,B were correlated to CNR（P0.05）.The correlation coefficient of CNR,SNR and RL were greater than that of AP.Except 2 level of group A,the correlation coefficient of CNR,SNR and AP were greater than that of BMI.Conclusion：Thoracic diameter can be used as guider to select the appropriate scan protocol in the coronary imaging acquisition with Somatom Definition Flash dual source CT.