摘要
Abstract
Objective To assess the impacts of Iterative Reconstruction (IR) technique on the image quality and radiation dose for scull scanning reconstruction.Methods The research was conducted based on 80 patients who had suffered craniocerebral trauma or required skull repair.According to the principle of random distribution,the patients were divided into 4 groups evenly,20 cases in each group.The control group (Group A) was scanned by using the conventional tube current and reconstructed by using FBP.With step-by-step reduced tube current output,the Group B,C,and D were scanned with the same kVp but the radiation doses were reduced by 50%,60% and 70% respectively,and were reconstructed by using ASIR.Quantitative measurements of image SNR and CNR were obtained in each group.The One-way Analysis of Variance (ANOVA) was applied to the comparisons of objective evaluation indexes (CT values,SD,SNR,CNR) and those of the differences of radiation dose(CTDI,DLP,ED) between four groups.Moreover,the Kruskal-Wallis test was applied to comparisons of differences in subjective evaluations of Image Quality (Contrast Ratio,Edge Sharpness,Subjective Noise,and Overall Image Quality) between four groups.Significance test of difference was also included (a level of P<0.05 was considered to be statistically significant).Results The differences in CT values,SD、SNR,and CNR between four groups are insignificant (P>0.05).The kappa values of contrast,sharpness,noise,and image quality were found to be 0.73,0.74,0.76,and 0.80,respectively,which demonstrates favorable consistency (Kappa>0.75).Therefore,the four groups suggest good subjective IQ (i≥3) and insignificant difference (P>0.05),and significant differences in CTDI、DLP、ED between the 4 groups (P<0.05).Conclution The Iterative Reconstruction is instrumental for lowering the noise and is able to maintain the image quality satisfying the demands of diagnosing while the scanning dose is reduced by 70%.关键词
体层摄影术,发射型计算机/图像处理,计算机辅助/辐射剂量Key words
Tomography,emission-computed/Image processing,computer-assisted/Radiation dosage分类
医药卫生
