胸围调节管电压技术冠状动脉CT血管成像的图像质量和辐射剂量  

The effect of chest circumference index adjusting tube voltages technique on image quality and radiation dose at coronary CT angiography

作　　者：王海林[1] 纪建松[1] 卢陈英[1] 胡翔华[1] 陈敏江[1] 翁巧优 杨宏远[1] 

机构地区：[1]浙江省丽水市中心医院放射科,323000

出　　处：《中华放射学杂志》2016年第4期284-288,共5页Chinese Journal of Radiology

基　　金：浙江省公益技术研究社会发展项目（2015C33260）;丽水市公益性技术应用项目（2011JYZB02）

摘　　要：目的探讨采用胸围调节管电压技术行冠状动脉CTA对图像质量和辐射剂量的影响。方法前瞻性连续选取体质量指数（BMI）〈25kg／m2，临床疑诊冠心病拟行冠状动脉CTA检查的120例患者。采用随机数字表法选取40例为常规组，其余80例为低剂量组。低剂量组再根据胸围分为3个亚组，A组胸围〈80cm（16例），B组胸围80～90cm（44例），C组胸围〉90cm（20例）。患者均行冠状动脉CTA检查，常规组采用回顾性心电门控，滤波反投影算法重组，管电压120kV，管电流1000mAs。低剂量组采用前瞻性心电门控技术，迭代算法重组；A、B、C组的管电压分别为80、100、120kV，管电流均为150mAs。对图像质量进行主观评价（图像质量评分）和客观评价（主动脉信噪比），并记录有效辐射剂量。采用Wilcoxon符号秩和检验或单因素方差分析比较各组图像质量和辐射剂量的差异。结果常规组和低剂量A、B、C组的图像质量评分分别为（3．47±0．38）、（3．48±0．27）、（3．45±0．32）、（3．46±0．29）分，主动脉信噪比分别为（15．5±3．6）、（15．8±3．6）、（15．8±4．1）、（16．2±3．9），差异均无统计学意义（P值分别为0．24、0．43）；上述各组的有效辐射剂量分别为（17．15±3．25）、（0．88±0．02）、（1．38±0．05）、（2．32±0．04）mSv，差异有统计学意义（P=0．02），各低剂量组的有效辐射剂量均低于常规组。结论采用胸同调节管电压技术行冠状动脉CTA，在保证图像质量的同时，可以有效降低辐射剂量。Objective To explore the effect of chest circumference index adjusting tube voltage techniquey on image quality and radiation dose at coronary CTA. Methods One hundred and twenty consecutive patients [body mass index（BMI）〈25 kg/m2] with suspected coronary heart disease （CHD） undergoing coronary CT angiography were prospectively selected and divided into 2 groups at random： conventional group and low dose group. Low dose group was divided into the following three subgroups according to different chest circumferences： A group（〈80 cm, n=16）, B group（80 to 90 era, n=44） and C group （〉90 cm, n=20）. All patients were examined by coronary CTA. The patients in conventional group were performed using retrospective ECG-gating technology and reconstructed by filtered back projection algorithm. The tube voltage/tube current was 120 kV/1 000 mAs. Prospective ECG-gating technology and iterative algorithm reconstruction were used in low dose group. The tube voltages/currents were 80 kV/150 mAs, 100 kV/150 mAs, 120 kV/150 mAs in A, B, C group, respectively. Image quality was assessed by subjective evaluation （image quality score） and objective evaluation （signal-to-noise ratio）.The effective radiation dose was calculated. Analyses of the differences between groups were compared with image quality, radiation dose by single factor variance and Wilcoxon signed ranks test.Results The image quality scores and signal-to-noise ratio of aorta were respectively （3.47 ± 0.38）, （3.48 ±0127）, （3.45 ±0.32）,（3.46±0.29） and （15.5±3.6）, （15.8±3.6）, （15.8±4.1）, （16.2±3.9） in conventional, A, B and C groups, there was no statistical difference between the four groups （P=0.24, 0.43）. The effective radiation dose of four groups were respectively （17.15±3.25）, （0.88±0.02）, （1.38±0.05）, （2.32±0.04） mSv, the difference was statistically significant （P=0.02）. The effective radiation dose of A, B, C group was significantly lower than that in the con

关 键 词：冠状血管 体层摄影术 X线计算机 辐射剂量 胸围 

分 类 号：R816.2[医药卫生—放射医学]