Influence of adaptive statistical iterative reconstruction-V on image quality and radiation dose of abdominal CT in phantom / 中国医学影像技术

ABSTRACT

Objective To evaluate the influence of preset adaptive statistical iterative reconstruction-V (ASIR-V) techniques on image quality and radiation dose reduction of abdominal CT in phantom,and to investigate the optimal ASIR-V level.Methods Abdominal anthropomorphic phantom was scanned using Revolution CT,when noise index (NI) were set as 6,8,10,12 and 14,respectively.Then 0-100％ ASIR-V and conventional scan was performed and 55 sets of images were obtained.CT value,noise,subjective score and radiation dose were recorded,and the optimal ASIR-V was obtained.Subjective scores of images in each group were compared using rank sum test,and CT value,noise and radiation dose were compared with one way ANOVA and paired t test.Results The image subjective score unchanged when NI was 6,8 or 10,slightly increased when NI was 12 and 14 with 0-40％ ASIR-V,and decreased above 50％ ASIR-V at all NI.When NI was 6,8 or 10,more than 70％ ASIR-V image subjective score fell below 3 points.When NI was 12 or 14 group,more than 60％ ASIR V subjective score fell below 3 points.The image quality score of conventional scan had no difference with 40％ ASIR-V when NI was 6,8 or 10,respectively (P=0.626,0.915,0.514),and inferior to 40％ ASIR-V when NI was 12 or 14 (P=0.041,0.036),while in all NI group,image quality score of conventional scan was superior to 60％ ASIR-V (P=0.021,0.012,0.015,0.014,0.007).CT values and image noises had no significant differences in different parts in all NI groups (all P＞0.05).CT dose index volume (CTDIvol) continuing decreased with ASIR-V.Compared with that of conventional scan,at 40％,50％ and 60％ ASIR-V,CTDIvol reduced by 49.82％,62.51％ and 71.63％,respectively.Conclusion Preset ASIR-V can reduce radiation dose obviously while maintaining the overall image quality,and 40％-60％ ASIR-V can be recommended for abdominal CT in clinical application.