二代双源CT缩短R-R间期曝光期相评价冠状动脉成像辐射剂量图像质量的可行性研究  

作　　者：杨琴 梁卡丽 余飞 代平 何其舟 

机构地区：[1]西南医科大学附属中医医院,646000

出　　处：《浙江临床医学》2020年第4期567-569,共3页Zhejiang Clinical Medical Journal

摘　　要：目的对23kg/m^2≤身体质量指数(BMI)≤28kg/m2的患者采用自适应性前瞻性心电门控序列扫描,探讨缩短R-R间期曝光期相、降低管电压、迭代重建技术降低辐射剂量的可行性.方法选取2018年2月至8月在本院行冠状动脉CTA检查的患者,共120例,采用数字法随机分为A、B、C组,每组各40例.采用自适应性前瞻性心电门控序列扫描模式,A组在30%~75%R-R间期期相曝光,管电压120kV,重建方式为传统反滤波投影.B组和C组均选择窄的R-R间期曝光(HR≤70次/min在35%~45%R-R间期曝光,HR>70次/min在65%~75%R-R间期曝光),B组管电压120kV,C组100kV,重建方式为迭代重建.记录参数有容积剂量指数、剂量长度乘积、有效辐射剂量、感兴趣区域CT值、图像噪声、对比噪声比、信噪比;行主客观图像质量评价.结果A、B、C三组有效辐射剂量分别为(5.15±1.09)mSv、(2.48±0.41)mSv、(1.83±0.44)mSv,两两比较差异有统计学意义(P<0.05).A、B、C三组图像噪声分别为(24.36±3.22)、(17.77±2.07)、(22.32±2.56),差异有统计学意义(P<0.05).A、B、C三组信噪比分别为(13.69±2.37)、(18.94±2.17)、(18.26±2.63),对比噪声比分别为(17.49±2.82)、(21.62±3.45)、(22.95±2.92);A组分别与B、C组的信噪比、对比噪声比比较差异有统计学意义(P<0.05).三组冠状动脉主观图像质量总体评价差异均无统计学意义(P>0.05).结论采用二代双源CT自适应性前瞻性心电门控序列扫描,缩短R-R间期曝光期相、降低管电压、采用迭代重建算法,能降低辐射剂量,并且图像质量满足诊断要求.Objective To discuss the feasibility of decreasing radiation dose by shortening R-R interval exposure phase and combine low tube voltage and the iterative reconstruction techniques,and prospective ECG-gating on patients with normal body mass index(23kg/m^2≤BMI≤28kg/m^2).Methods 120 cases of patients who conducted CT angiography of coronary artery from February 2018 to August 2018 were selected.The patients were randomly divided into three groups of A,B,C,and 40 cases were in each group.The adaptive prospective ECG-gated sequence scan mode was used in three groups.In group A,a wide R-R interval was selected for exposure(30%~75% of R-R interval)with the 120kV tube voltage and reconstruction of conventional filtered back projection.In group B and C,a narrow R-R interval was selected for exposure(heart rate≤70beats/min to select 35%~45% of R-R interval,heart rate>70 beats/min to select 65%-75%of R-R interval).The tube voltage of group B was 120kV,and group C was 100kV.Coronary artery images were reconstructed by iteration method in both groups.The CT dose index volume,dose-length product,effective radiation dose,CT value of the region of interest,image noise,signal to noise ratio and contrast to noise ratio were recorded.The image quality of coronary arteries in three groups were scored and statistically analyzed.Results The CT effective radiation dose of group A,B and C were(5.15±1.09,2.48±0.41,1.83±0.44)mSv respectively.The difference of group among the three groups was statistically significant(P<0.05).The image noise of group A,B and C were(24.36±3.22,17.77±2.07,22.32±2.56),respectively.The difference of group among the three groups was statistically significant(P<0.05).The signal to noise ratios of group A,B and C were(13.69±2.37,18.94±2.17,18.26±2.63)and the CNR were(17.49±2.82,21.62±3.45,22.95±2.92)respectively.There was significant difference between group A and group B,group A and group C(P<0.05).The subjective evaluation of image quality of coronary arteries in group A,B and C was not stat

关 键 词：低管电压 前瞻性心电门控技术 R-R间期 辐射剂量 

分 类 号：TP3[自动化与计算机技术—计算机科学与技术]