Application of low-dose chest CT screening with iterative reconstruction technique(iDose~4)

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(22BMI26) and group C(BMI≥26).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.