3种不同迭代重建技术在胸部低剂量CT扫描中的应用  

Application of three different iterative reconstruction techniques in low-dose chest CT scan

作　　者：唐慧 杨军乐 贺太平 李永斌 时宏[1] 任占丽 薛久华[1] 刘婷 和鸿[1] TANG Hui;YANG Junle;HE Taiping;LI Yongbin;SHI Hong;REN Zhanli;XUE Jiuhua;LIU Ting;HE Hong(Department of Radiology,Xi'an No.1 Hospital,Xi'an 710002,China;Department of Medical Imaging,the Affiliated Hospital of Shaanxi University of Chinese Medicine,Xianyang,Shaanxi Province 712000,China)

机构地区：[1]西安市第一医院医学影像科,陕西西安710002 [2]陕西中医药大学附属医院医学影像科,陕西咸阳712000

出　　处：《实用放射学杂志》2022年第6期1003-1006,共4页Journal of Practical Radiology

基　　金：西安市卫生健康委员会科研项目(西安市第一医院青年培养项目)(2020qn04)。

摘　　要：目的探讨3种不同迭代重建技术[自适应统计迭代重建(ASIR)、基于多模型自适应迭代重建(ASIR-V)、新一代基于模型迭代重建(MBIR)]在降低胸部CT辐射剂量和提高图像质量中的应用价值.方法收集100例患者初诊和6个月内复查的2组胸部平扫CT图像.所有患者初诊采用常规剂量方案[预设噪声指数(NI)=14],图像采用ASIR 60%进行重建,复查采用低剂量方案(预设NI=28),分别采用ASIR 60%、ASIR-V 60%、MBIR 3种不同迭代重建技术对同一患者的CT图像进行重建.在气管隆嵴水平测量皮下脂肪、背部肌肉和降主动脉的CT值和标准差(SD)值,计算3种组织的信噪比(SNR).记录2组容积CT剂量指数(CTDIvol)及有效剂量(ED).由2名经验丰富的放射科医师采用盲法对2组重建图像进行主观评价.结果低剂量MBIR图像客观噪声(SD值)明显低于低剂量ASIR 60%和低剂量ASIR-V 60%,稍低于常规剂量ASIR 60%,差异有统计学意义(P<0.05);同时,低剂量MBIR图像SNR明显高于低剂量ASIR 60%和低剂量ASIR-V 60%,稍高于常规剂量ASIR 60%,差异有统计学意义(P<0.05).图像主观评分,低剂量MBIR图像明显优于低剂量ASIR 60%和低剂量ASIR-V 60%,略优于常规剂量ASIR 60%,差异有统计学意义(P<0.05).与常规剂量方案相比,低剂量方案中的ED降低了约74.2%(P<0.05).结论与ASIR和ASIR-V相比,MBIR能够显著降低图像噪声,提高图像SNR,并且低剂量CT扫描条件下使用MBIR的影像图像仍具有较高的图像质量.Objective To explore the application value of three different iterative reconstruction techniques[adaptive statistical iterative reconstruction(ASIR),adaptive statistical iterative reconstruction veo(ASIR-V),model-based iterative reconstruction(MBIR)]in reducing the radiation dose and improving the image quality of chest CT.Methods Two groups of chest plain CT images of 100 patients were collected in first examination and re examination within half a year.The first examination of all the patients was performed using a conventional dose plan with the noise index(NI)of 14,and the images were reconstructed by using ASIR 60% algorithm.:The re examination was performed using a low radiation dose plan with the NI of 28,and the three different iterative reconstruction techniques of ASIR 60%,ASIR-V 60%,and MBIR were used to reconstruct CT images for the same patient.The CT and standard deviation(SD)values of subcutaneous fat,back muscle,and descending aorta were measured at the level of the tracheal carina,and the signal-to noise ratio(SNR)of the three tissues were calculated.The volume CT dose index(CTDIvol)and effective dose(ED)were recorded in the two groups.T wo experienced radiologists subjectively evaluated the two groups of reconstructed images with a blind method.Results The SD value of low dose MBIR images was significantly lower than those of low-dose ASIR 60% and ASIR-V 60% images,and slightly lower than that of conventional dose ASIR 60% images.There were significant differences(P<0.05).The SNR of low-dose MBIR images was significantly higher than those of low-dose ASIR 60% and ASIR-V 60% images,and slightly higher than that of conventional dose ASIR 60% images.There were significant differences(P<<0.05).Subjective image scores of low dose MBIR images were significantly higher than those of low-dose ASIR 60% and ASIR-V 60% images,and slightly higher than that of conventional dose ASIR 60% images.There were significant differences(P<0.05).Compared with the conventional dose group,the ED in low dose CT was redu

关 键 词：迭代重建 胸部 低剂量 计算机体层成像 

分 类 号：R816.4[医药卫生—放射医学] R814.42[医药卫生—临床医学]