噪声指数及体质量指数对儿童胸部CT低剂量扫描的影响  

Effect of noise index and body mass index on radiation dose and image quality in low dose chest CT scanning in children

作　　者：余才锋 邵长春 姜骏 丁姜鹏 毛莉琳 YU Caifeng;SHAO Changchun;JIANG Jun;DING Jiangpeng;MAO Lilin(Department of Radiology,Shangrao Maternal and Child Health Hospital,Shangrao 334000,China)

机构地区：[1]江西省上饶市妇幼保健院放射科,上饶334000

出　　处：《国际医学放射学杂志》2025年第1期1-5,58,共6页International Journal of Medical Radiology

基　　金：江西省卫健委科技计划项目(202312315)。

摘　　要：目的探讨噪声指数(NI)及体质量指数(BMI)对儿童胸部低剂量CT扫描的辐射剂量及影像质量的影响。方法前瞻性纳入拟行胸部CT低剂量扫描的1~10岁患儿689例,患儿BMI 10.62~22.40 kg/m^(2),平均(15.36±3.26)kg/m^(2)。设置5种CT扫描NI(10、15、20、25、30),患儿分别有124例、129例、166例、202例和68例。以14、16 kg/m2为BMI临界值将患儿分为3组,即低BMI组(BMI<14 kg/m^(2),175例)、中等BMI组(14 kg/m^(2)~<16 kg/m^(2),283例)、高BMI组(≥16 kg/m^(2),231例)。分析不同NI、BMI对胸部CT扫描的辐射剂量与影像质量的影响,并计算不同组合的合计得分,获得最佳组合。采用单因素方差分析比较5种NI中不同BMI组间患儿CT检查的辐射剂量及影像质量客观参数。结果NI为10和30时,不同BMI组间的CT容积剂量指数(CTDIvol)、剂量长度乘积(DLP)、有效辐射剂量(ED)以及CT值的标准差(SD)、信噪比(SNR)的差异均无统计学意义(均P>0.05)。NI为15、20、25时,随着BMI的增加,CTDIvol、DLP、ED逐渐增大(均P<0.05);而SD、SNR的差异均无统计学意义(均P>0.05)。在低BMI组和中等BMI中,NI值为30的DLP和SNR合计得分均高于其他NI值;在高BMI组中,NI值为25时,DLP和SNR合计得分高于其他NI值。在同一BMI组中,影像质量主观评分随着NI的增加而逐渐减低。结论对1~10岁儿童进行胸部CT扫描时,根据患儿BMI的不同选择相应的NI,不仅大大降低辐射剂量,还能保证其影像质量满足临床诊断要求。Objective To investigate the effects of noise index(NI)and body mass index(BMI)on radiation dose and image quality in low dose chest CT scanning in children.Methods A total of 689 children aged 1 to 10 years were prospectively enrolled,with BMI ranging from 10.62 to 22.40 kg/m^(2)(mean BMI:15.36±3.26 kg/m^(2)).Five different noise index(NI)levels were set(10,15,20,25,and 30),with 124,129,166,202,and 68 children in each respective group.The children were divided into three BMI groups based on BMI thresholds of 14 and 16 kg/m^(2):low BMI group(BMI<14 kg/m^(2),175 cases),medium BMI group(14-<16 kg/m^(2),283 cases),and high BMI group(BMI≥16 kg/m^(2),231 cases).The impact of different NI and BMI on radiation dose and image quality of chest CT scans was analyzed,and the total scores of different combinations were calculated to determine the optimal combination.One-way analysis of variance(ANOVA)was used to compare radiation dose and image quality objective parameters in different BMI intervals across the five NI levels.Results When NI was 10 or 30,there were no significant differences in CT volume dose index(CTDIvol),dose length product(DLP),effective radiation dose(ED),standard deviation(SD)of CT value,and signal-to-noise ratio(SNR)among the different BMI groups(all P>0.05).When the NI was 15,20,or 25,CTDIvol,DLP and ED increased progressively with BMI(all P<0.05).There was no significant difference in SD and SNR(P>0.05).In the low BMI group and medium BMI group,DLP and SNR total scores at NI=30 were higher than those at other NI levels.In the high BMI group,the DLP and SNR total score were higher at NI=25 compared to other NI levels.Within the same BMI group,the subjective score of image quality decreased gradually as the NI increase.Conclusion For children aged 1-10 years undergoing chest CT scans,selecting an appropriate NI based on the child’s BMI can significantly reduce radiation dose while ensuring that image quality meets clinical diagnostic requirements.

关 键 词：噪声指数 体质量指数 低剂量 儿童 胸部 体层摄影术 X线计算机 

分 类 号：R814.42[医药卫生—影像医学与核医学] R816.4[医药卫生—放射医学]