不同定位方法对儿童胸部CT检查图像质量和辐射剂量的影响  

Effects of different positioning methods on chest CT image quality and radiation dose of children

作　　者：葛宁 杨文忠[1] 程颖[2] 刘萍 GE Ning;YANG Wen-zhong;CHENG Ying;LIU Ping(Department of Medical Imaging,Maternal and Child Hospital of Hubei Province,Wuhan 430070,China;Department of Pediatric Intensive Care,Maternal and Children Hospital of Hubei Province,Wuhan 430070,China)

机构地区：[1]湖北省妇幼保健院医学影像科,武汉430070 [2]湖北省妇幼保健院儿童重症医学科,武汉430070

出　　处：《医疗卫生装备》2021年第2期47-49,108,共4页Chinese Medical Equipment Journal

摘　　要：目的:探讨不同定位方法对儿童进行胸部CT检查产生的辐射剂量及采集的图像质量的影响。方法:收集某院儿童重症医学科行胸部CT检查年龄3岁左右的患儿30例,随机分为常规定位组(采用正位定位像,常规目测腋中线定位)和辅助定位组(体厚卡尺辅助定位),每组各15例。分别采集2组患儿胸部CT容积剂量指数(CT dose index volume,CTDIvol)和剂量长度乘积(dose length product,DLP),并计算有效辐射剂量(effective dose,ED),比较不同定位方法得到的图像质量及辐射剂量,以P<0.05为差异有统计学意义。结果:采用常规定位组和辅助定位组之间的图像质量主观评分差异没有统计学意义(χ2=0.680,P>0.05);客观图像质量信噪比(signal to noise ratio,SNR)及对比噪声比(contrast to noise ratio,CNR)的差异没有统计学意义(t=0.586、0.432,P>0.05);对于辐射剂量CTDIvol、DLP、ED,辅助定位组明显小于常规定位组,差异具有统计学意义(t=4.252、6.632、6.632,P<0.001)。结论:利用体厚卡尺辅助定位进行儿童胸部CT检查,通过侧面一个定位像即可明确扫描范围,辐射剂量较常规使用正位定位像大为减少,具有一定的临床意义。Objective To explore the effects of different positioning methods on radiation dose and image quality during chest CT examination of children.Methods A total of 30 children around 3 years old undergoing chest CT scans were selected from the department of pediatric intensive care unit of some hospital and randomly divided into a conventional positioning group went through anteroposterior CT examination and realized positioning through visual inspection of midaxillary line and an auxiliary positioning group implemented positioning through a body thickness caliper,15 cases in each group.The values of CT dose index volume(CTDIvol)and dose length product(DLP)were collected in the two groups,and the effective dose(ED)was calculated.The image quality and radiation dose generated by different positioning methods were compared and P values lower than 0.05 were considered statistically significant.Results There were no significant differences in the subjective image quality scores between the two groups(χ2=0.680,P>0.05);the values of the objective image quality signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)were not statistically significant(t=0.586,0.432 and P>0.05)in the two groups;the auxiliary positioning group had the values of CTDIvol,DLP and EP obviously lower than those in the conventional group,and the differences were statistically significant(t=4.252,6.632,6.632 and P<0.001).Conclusion The children chest CT examination by means of body thickness caliper-assisted positioning clarifies the scan scope by scanning from a lateral scout view,the radiation dose is greatly reduced campared with the conventional use of ortho positioning image,which is of significance for clinical application.[Chinese Medical Equipment Journal,2021,42(2):47-49,108]

关 键 词：儿童 常规定位 辅助定位 辐射剂量 图像质量 

分 类 号：R318[医药卫生—生物医学工程] R814.42[医药卫生—基础医学]