迭代重建技术(iDose4)在肺部低剂量筛查中的应用

摘要

目的 探讨iDose4迭代重建技术在胸部低剂量筛查的方案.方法 选取120例胸部体检者,根据不同的体质量指数(BMI)分为A组(BMI≤22)、B组(22＜BMI＜26)和C组(BMI≥26).应用Z轴动态管电流调节技术(Z-DOM),预设A组、B组、C组管电流分别为35 mAs、45 mAs和60 mAs,之后利用iDose4平台对各受检者图像分别进行FBP,iDose3、Dose5、iDose7重建.记录3组的CT剂量指数(CTDIvol)、剂量长度乘积(DLP),并估算有效剂量(ED).结果 所获图像质量均可满足诊断要求.A组、B组和C组的CTDIvol均值分别为(0.69±0.08)mGy、(1.09±0.17)mGy和(1.95±0.43)mGy,ED均值分别为(0.33±0.05)mSv、(0.50±0.11)mSv和(0.87±0.23)mSv.结论 应用iDose4迭代重建技术,根据受检者的BMI,可获得满意的胸部低剂量CT筛查扫描方案.%Objective To assess the program of low dose chest CT screening with iterative reconstruction technique (iDose4). Methods Totally 120 subjects who underwent chest CT screening were divided into 3 groups according to body mass index (BMI): Group A (BMI≤22) , group B (2226). Z-axial dose modulation (Z-DOM) technique was used to preset tube current of group A, group B and group C as 35 mAs, 45 mAs and 60 mAs, respectively. Then the images were reconstructed with standard filtered back projection (FBP) , iDose3, iDose5 and iDose7, respectively. CT dose index volumes (CTDIvol) and dose length product (DLP) were recorded, while effective dose (ED) was estimated. The imaging quality was assessed by 2 radiologists. Results The images of each group were acceptable. The average CTDIvol for group A, B and C was (0. 69 + 0. 08)mGy, (1. 09 + 0. 17)mGy and (1. 95 + 0. 43)mGy, respectively, and the average ED was (0. 33 + 0. 05)mSv, (0. 50±0. 11) mSv and (0. 87 + 0. 23) mSv, respectively. Conclusion Application of iDose4 iterative reconstruction technique based on BMI can achieve satisfactory scanning program of chest low-dose screening.