Parameter optimization of low-dose Flash CT scan of the chest:an animal experiment / 实用放射学杂志

ABSTRACT

Objective To explore the optimized scanning parameters of low-dose un-enhanced chest CT with sinogram affirmed iterative reconstruction (SAFIRE).Methods Eleven healthy adult domestic dogs underwent chest scanning of 120 kV,100 kV,80 kV,70 kV with a fixed tube current of 65 mA and halved tube current of 32 mA with a fixed tube voltage of 100 kV.The data were reconstructed with filtered back projection (FBP)and SAFIRE (strength grade 3)respectively to obtain ten groups of images.The regular dose (120 kV/65 mA ) combining with FBP reconstruction was as normal control group,and other groups as experimental groups.CT dose index (CTDI), dose length product (DLP),and effective dose (ED)at different dose were compared,and average CT value,noise,signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR)and image quality score of ten groups of images were comparatively analyzed.Results No significant differences were found in average CT value for lung tissue,the superior vena cava,the aortic arch,and spinal muscles among ten groups (P >0.05),except adipose tissue (P 3),and the radiation dose of this group decreased by 81.33%.Conclusion Reconstructed with SAFRIE technology,the image quality of 100 kV/65 mA scanning of chest CT is similar to that of routinely reconstructed images in regular dose,while the image quality of 70 kV/65 mA scanning can not only meet the requirements of diagnosis but also obviously reduce radiation dose.