CT扫描中非标准定位像对图像质量和辐射剂量影响的模体研究OACSTPCD

Objective To investigate the impact of non-standard localizer radiographs on the image quality and radiation dose of spiral CT scans through phantom experiments.Methods A standard localizer radiograph including the phantom was utilized for scanning the phantom and obtaining baseline group images,followed by a non-standard localizer radiograph containing the phantom and syringe to scan the phantom for non-baseline group images.The quality parameters of the two groups of images were compared including noise,linear CT value(3 materials:Teflon,LDPE,Air),density resolution and spatial resolution.Additionally,dose-related parameters between the two scanning protocols including effective milliampere seconds(eff.mAs)and CT dose index volume(CTDIvol)were compared.Results The comparison of noise in baseline group was lower than that in non-baseline group(P<0.05).Regarding CT value linearity,the baseline group showed a closer alignment to the standard CT value than the non-baseline group(P<0.05).In terms of density resolution,the baseline group significantly outperformed the non-baseline group in identifying the smallest diameter of the hole array(P<0.05).The difference was not statistically significant in spatial resolution between the two image groups(P>0.05).In the comparison of scanning protocols between the two groups,the eff.mAs and CTDIvol were higher in the non-baseline group than in the baseline group(all P<0.05).Conclusion Using standard localizer radiographs in spiral CT scans can achieve image quality requirements with lower radiation doses.The use of non-standard positioning images not only increases the radiation dose,but also damages the image quality.