不同前置和后置自适应统计迭代重建算法权重在冠状动脉CT血管成像中的研究  

Comparison of image quality and radiation dose using different percentage pre-and post-adaptive statistical iterative reconstruction V in coronary CT angiography

作　　者：赵永霞[1] 李冬雪 张天乐[1] 耿雪 徐艺泽 左紫薇 ZHAO Yongxia;LI Dongxue;ZHANG Tianle;GENG Xue;XU Yize;ZUO Ziwei(Department of Radiology,the Affiliated Hospital of Hebei University,Baoding,Hebei Province 071000,China)

机构地区：[1]河北大学附属医院放射科,河北保定071000

出　　处：《实用放射学杂志》2022年第4期646-650,共5页Journal of Practical Radiology

基　　金：河北省政府资助临床医学优秀人才培养和基础课题研究项目(361007);河北省重点研发计划项目(203777650);河北省2020年医学科学研究课题计划项目(20200572);河北大学2019年研究生创新资助项目(hbu2019ss037);河北大学附属医院重点基金项目(2019Z004);河北大学医学学科培育项目(2021A10,2021X06).

摘　　要：目的探讨不同前置和后置自适应统计迭代重建算法(ASiRGV)水平在冠状动脉CT血管成像(CCTA)中图像质量和辐射剂量的比较研究.方法前瞻性将150例行CCTA检查患者随机分为A、B、C、D、E5组并采用前置40%、50%、60%、70%、80%ASiRGV权重和后置70%ASiRGV权重进行扫描,计算所有图像的信噪比(SNR)和对比度噪声比(CNR),采用5分法进行主观评分,记录各组患者的容积CT剂量指数(CTDI_(vol)),剂量长度乘积(DLP),计算有效剂量(ED).经统计学分析,优化出在保证图像质量前提下辐射剂量最低的前置ASiRGV权重值.将优化的最佳前置ASiRGV权重值(D组)图像分别用40%~90%,间隔为10%的后置ASiRGV重建出D0、D1、D2、D3、D4、D5共6个亚组图像,计算各亚组图像的SNR、CNR及主观评分.优化出图像质量最佳的后置ASiRGV权重值.结果统计学分析显示:A、B、C、D组图像的SNR值、CNR值及主观评分无统计学差异,E组图像的SNR值、CNR值及主观评分均低于A、B、C、D组(P<0.001).B、C、D组的平均ED值较A组分别降低7.01%、13.37%和18.87%;D4和D5亚组图像的SNR和CNR高于其他亚组,且D4亚组图像的主观评分高于其他亚组(P<0.001).结论宽体探测器联合前置70%ASiRGV并结合后置80%ASiRGV在保证图像质量的前提下与设备生产商推荐的前置40%的ASiRGV相比,可明显地降低行CCTA患者的辐射剂量.Objective To characterize the optimal pre-and post-adaptive statistical iterative reconstruction V(ASiR-V)for improving image quality and reducing the radiation dose in coronary computed tomography angiography(CCTA).Methods 150 patients for CCTA were prospectively enrolled and randomly divided into five groups(A,B,C,D,and E),with progressive seanning from 40%to 80%pre-ASiR-V with 10%intervals and reconstructing with 70%post-ASiR-V.The signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)were calculated.Subjective image quality was assessed using a five-point scale.The volume CT dose index(CTDI_(vol))and dose length product(DLP)of each patient were recorded and the effective dose(ED)was calculated after statistical analysis by optimizing for the best pre-ASiR-V value with the lowest radiation dose while maintaining overall image quality.The images with the best pre-ASiR-V value(group D)were reconstructed into 6 subgroups(D0,D1,D2,D3,D4,D5)with 40%-90%(interval 10%)post-ASiR-V.The SNR,CNR and subjective scores of each subgroup were recorded after statistical analysis by optimizing for the best post-ASiR-V value while maintaining overall image quality.Results There was no significant difference in the SNR,CNR,and image quality scores among A,B,C,and D groups.The SNR,CNR,and image quality scores of the E group were lower than those of the A,B,C,and D groups(P<0.001).The mean ED values in the B,C,and D groups were reduced by 7.01%,13.37%,and 18.87%,respectively,when compared with those of the A group.The SNR and CNR of the D4-D5 subgroups were higher than those of the DO-D3 subgroups,and the image quality scores of the D4 subgroups were higher than those of the other subgroups(P<0.001).Conclusion The 70%pre-ASiR-V and 80%post-ASiR-V significantly reduced the radiation dose of CCTA while maintaining overall image quality compared with the manufacture's recommendation.

关 键 词：冠状动脉CT血管造影 自适应统计迭代重建算法 辐射剂量 图像质量 

分 类 号：R331.32[医药卫生—人体生理学] R814.42[医药卫生—基础医学] R814.49