摘要
目的统计以容积CT剂量指数(CTDI_(vol))、基于水当量直径(WD)的体型特异性剂量估算值(SSDEWD)及剂量长度乘积(DLP)为衡量指标的儿童头颅、胸部及腹盆部CT检查诊断参考水平(DRL)典型值,衡量本医疗机构CT检查辐射水平。方法回顾性收集2021年1月至2021年12月间南京医科大学附属儿童医院收治的头颅1391例,胸部1386例及腹盆部1035例患者CT影像资料,分别记录其年龄、CTDI_(vol)、DLP,手动测量最中间扫描图像的前后径(AP)、左右径(LAT)、兴趣区面积(AROI)及面积内CT值(CTROI),按照美国医学物理学家学会(AAPM)报告方法,计算有效直径(d)、WD、转换因子(f16/32XSIZE)及SSDEWD;将各检查部位分别按照年龄及体型进行分组:按照年龄分为<1、1~、5~、10~、15~岁5组,各分组患儿数分别为:头颅252、320、400、380及39例;胸部188、320、399、398及81例;腹盆部75、310、310、300及40例。头颅基于LAT分为<12.5、12.5~、14~、15~、16~cm 5组,每组患儿分别为151、222、319、399及300例;胸部、腹盆部基于d分为<15、15~、20~、25~、30~cm 5组,每组患儿分别为胸部275、527、400、165及19例;腹盆部403、410、184、34及4例。统计各分组内CTDI_(vol)、SSDEWD和DLP的第75百分位数,将其作为DRL典型值;并比较CTDI_(vol)和SSDEWD在衡量辐射剂量上的差异。结果按年龄分组,以CTDI_(vol)为衡量指标的头颅、胸部、腹盆部DRL典型值分别为14.9~24.1、1.8~4.5和2.0~7.5 mGy;以SSDEWD为衡量指标的DRL典型值分别为14.7~18.9、4.2~6.9和4.7~11.8 mGy;以DLP为衡量指标的DRL典型值分别为260~505、40~185和65~435 mGy·cm。按d分组,以CTDI_(vol)为衡量指标的胸部、腹盆部DRL典型值分别为1.8~6.8和2.2~9.2 mGy;以SSDEWD为衡量指标的DRL典型值分别为4.2~9.1和4.9~13.0 mGy;以DLP为衡量指标的DRL典型值分别为40~255和85~545 mGy·cm。头颅按LAT分组,以CTDI_(vol)为衡量指标的DRL典型值为14.1~23.1 mGy;以SSDEWD为衡量指标的DRL典�
Objective To calculate the typical values of diagnostic reference levels(DRLs)for CT examinations of head,chest and abdomen-pelvis in children using the volumetric CT dose index(CTDI_(vol)),the size-specific dose estimation value(SSDEWD)based on the water equivalent diameter(WD)and the dose length product(DLP)as indicators to measure the radiation dose level of CT examinations in Department of Radiology,Children′s Hospital of Nanjing Medical University.Methods The CT examination images of patients admitted to the Hospital from January 2021 to December 2021 were retrospectively collected,encompassing 1391 for head,1386 for chest and 1035 for abdomen-pelvis.Their age,CTDI_(vol) and DLP were recorded and the anterior-posterior diameter(AP),lateral diameter(LAT),area(AROI)and CT value within area(CTROI)of the middlemost scanned image were measured manually.The effective diameter(d),WD,conversion factor(f16/32XSIZE)and SSDEWD were calculated in accordance with the American Academy of Physicists in Medicine(AAPM)reported method.Patients were divided into 5 groups in terms of their examined site.age and body size:<1,1-,5-,10-,and 15-years old.The number of patients in each group was 252,320,400,380 and 39 for the head,188,320,399,398 and 81 for the chest,and 75,310,310,300 and 40 for the abdomen-pelvis region.The patients for head examination was divided into five groups of<12.5,12.5-,14-,15-,16-cm based on LAT,with 151,222,319,399 and 300 cases in each group,respectively.The chest and abdomen-pelvis were divided into five groups of<15,15-,20-,25-,30-cm based on d,with 275,527,400,165 and 19 cases in each chest group,respectively;the abdomen-pelvis 403,410,184,34 and 4 cases.The 75th percentile of CTDI_(vol),SSDEWDand DLP were counted in each group as typical DRL values,and the differences between CTDI_(vol) and SSDEWD in measuring radiation dose were compared.Results The typical values of DRL in the head,chest and abdomen-pelvis areas as measured by CTDI_(vol) were 14.9-24.1,1.8-4.5,and 2.0-7.5 mGy,respectively,by ag
作者
张见
杨凤
王颖
张晓军
Zhang Jian;Yang Feng;Wang Ying;Zhang Xiaojun(Department of Radiology,Children′s Hospital of Nanjing Medical University,Nanjing 210000,China)
出处
《中华放射医学与防护杂志》
CAS
CSCD
北大核心
2023年第1期56-62,共7页
Chinese Journal of Radiological Medicine and Protection
基金
江苏省政府留学基金(JS-2018-137)
江苏省妇幼保健课题(FYX201816)
南京市医学科技发展基金(QRX17169)。
关键词
儿童
计算机体层成像
诊断参考水平
Children
Computed tomography
Diagnostic reference level
