摘要
目的观察Karl迭代重建技术对低剂量CT定量评估婴幼儿肺密度及肺容积的影响。方法纳入100例临床疑诊呼吸系统疾病的婴幼儿,将其随机分为低剂量(LD)组及常规剂量(RD)组各50例;采集肺部平扫CT图像,对LD组分别以滤波反投影(FBP)算法及Karl 1、3、5、7、9级迭代重建技术重建图像,对RD组以FBP算法重建。记录2组有效剂量(ED),测量并比较各重建图像中的全肺平均肺密度(MLD)和全肺容积(LV)的差异,以及支气管分叉水平的主动脉、竖脊肌、胸腺、前胸壁皮下脂肪噪声值(SD)平均值及图像质量主观评价的差异。结果LD组ED较RD组下降84.44%。FBP重建图像中,LD组MLD和主观评分均低于RD组(P均<0.01),其LV和SD均高于RD组(P均<0.01)。LD组内Karl 1、3、5、7、9级重建图像中的MLD、LV、SD和主观评分差异均有统计学意义(P均<0.05);随Karl迭代等级升高,MLD逐渐升高、LV和SD则逐渐减低,Karl 7级与Karl 1级间各指标差异均有统计学意义(P均<0.05),主观评分以Karl 5级最高。LD组Karl 5级重建图像的MLD和主观评分均高于LD组FBP重建图像(P均<0.05)而低于RD组FBP重建图像(P<0.05);LV和SD均低于LD组FBP重建图像(P均<0.01),而高于RD组FBP重建图像(P<0.01)。结论低剂量定量CT可能低估婴幼儿MLD而高估其LV;Karl迭代重建技术能提高CT定量分析的准确性、降低图像噪声、提高图像质量,尤以Karl 5级迭代重建图像质量最佳。
Objective To observe the impact of Karl iterative reconstruction technology on low-dose CT quantitative assessment of lung density and lung volume in infants and young children.Methods A total of 100 infants and young children with clinically suspected respiratory diseases were enrolled and randomly divided into the low dose(LD)group and conventional dose(RD)group(each n=50).Plain CT scanning of lungs were acquired,and images of LD group were reconstructed with filtered back projection(FBP)algorithm and Karl 1,3,5,7 and 9 level iterative reconstruction techniques,while of RD group were reconstructed with FBP algorithm.The effective dose(ED)of 2 groups were recorded,and the mean lung density(MLD),lung volume(LV),the mean value of noise value(SD)of aorta,erector spinae,thymus,subcutaneous fat of anterior chest wall at the level of bronchial bifurcation and subjective evaluation of image quality were measured and compared.Results Compared with ED in RD group,ED in LD group decreased by 84.44%.Under FBP reconstruction,MLD and subjective scores in LD group were lower,while LV and SD were higher than those in RD group(all P<0.01).In LD group,there were significant differences of MLD,LV,SD and subjective scores among Karl 1,3,5,7,9 reconstruction(all P<0.05).With Karl iteration level increased,MLD gradually increased,LV and SD gradually decreased,and the above indexes were significantly different between Karl 7 and Karl 1(all P<0.05).The subjective score of Karl 5 reconstructed images was the highest.MLD and subjective scores of Karl 5 reconstructed images in LD group were higher than those of FBP reconstructed images in LD group(both P<0.05)but lower than FBP reconstructed images in RD group(P<0.05),whereas LV and SD were lower than those of FBP reconstructed images in LD group(both P<0.05)but higher than that of FBP reconstructed images in RD group(P<0.05).Conclusion Low dose quantitative CT would result underestimation of MLD and overestimation of LV in infants and young children.Karl iterative reconstruction technology could improve the accuracy of CT quantitative analysis,reduce image noise and improve image quality,and Karl 5 iterative reconstruction had the best image quality.
作者
朱彦瑾
赵凡惠
雷禹
牛媛
李建龙
黄晓旗
ZHU Yanjin;ZHAO Fanhui;LEI Yu;NIU Yuan;LI Jianlong;HUANG Xiaoqi(Department of Imaging,Yan'an University Affiliated Hospital,Yan'an 716000,China;Department of Imaging,the First Hospital of Yulin City,Yulin 719000,China;Department of Imaging,the Third Hospital of Xi'an City,Xi'an 710000,China)
出处
《中国医学影像技术》
CSCD
北大核心
2022年第4期599-603,共5页
Chinese Journal of Medical Imaging Technology
基金
陕西省重点研发计划(2021SF-254)。
关键词
儿童
肺容积测量
迭代重建
低剂量
child
lung volume measurements
iterative reconstruction
low dose
