CT头颈部检查所致婴幼儿眼晶状体吸收剂量估算方法的模体研究  

Study on estimation methods of absorbed dose to eye lens of infants from CT head and neck scanning based on one-year old anthropomorphic phantom

作　　者：杨珂[1] 于夕荣[1] 张显鹏[1] 柳怡[1] 唐波[1] 刘建伟[1] 刘海宽[2] Yang Ke;Yu Xirong;Zhang Xianpeng;Liu Yi;Tang Bo;Liu Jianwei;Liu Haikuan(Institute for Radiological Protection and Safety,Shandong Center for Disease Control and Prevention,Jinan 250014,China;Institute of Radiation Medicine,Fudan University,Shanghai 200032,China)

机构地区：[1]山东省疾病预防控制中心辐射防护安全所,济南250014 [2]复旦大学放射医学研究所,上海200032

出　　处：《中华放射医学与防护杂志》2019年第4期297-302,共6页Chinese Journal of Radiological Medicine and Protection

基　　金：国家自然科学基金(11475047).

摘　　要：目的探讨CT不同扫描方案检查所致婴幼儿眼晶状体吸收剂量估算方法,并寻求快速估算眼晶状体吸收剂量的实用方法。方法通过设置7种临床标准扫描方案,对1岁年龄组仿真模体进行扫描,利用布放在模体不同位置的热释光探测器(TLD)测量剂量,最后测量结果分别用组织因子转换和个人剂量当量转换两种方法来估算眼晶状体吸收剂量,同时将眼晶状体吸收剂量与CT剂量指数(CTDI)建立线性回归方程。结果7种临床标准儿童扫描方案CT检查所致的婴幼儿眼晶状体吸收剂量分别为(9.96±0.69) mGy(头部轴向)、(7.01±0.42) mGy(头部螺旋)、(12.60±0.97) mGy(副鼻窦)、(12.97±0.42) mGy(内耳高分辨)、(0.63±0.03) mGy(颈部软组织)、(8.89±0.44)mGy(颈部颈椎)和(0.34±0.01)mGy(胸部常规),不同组之间剂量差异有统计学意义(F=846.826,P<0.05)。不同扫描部位,CTDI值与眼晶状体吸收剂量之间均存在线性关系(r=0.986~0.999,P<0.05)。结论采用儿童CT扫描条件,婴幼儿眼晶状体吸收剂量单次剂量范围一般不会超过阈剂量。另外,通过读取CTDI值,利用线性关系,可快速估算眼晶状体吸收剂量。Objective To study the methods to estimate absorbed dose to eye lens of infants from CT scanning using different protocols and try to find a practical quick way for estimating absorbed dose to eye lens. Methods By scanning one-year old anthropomorphic phantom using 7 kinds of different protocols, all TLDs were measured for final estimation of absorbed dose to eye lens using two different dose conversion methods . Meanwhile, linear regression equation was established between absorbed dose to eye lens and CTDI. Results Absorbed doses to eye lens of infants from children CT scanning using 7 kinds of different protocols were (9.96±0.69) mGy in head axis,(7.01±0.42) mGy in head helical,(12.60±0.97) mGy in sinus,(12.97±0.42) mGy in inner ear,(0.63±0.03) mGy in neck soft tissue,(8.89±0.44) mGy in cervical vertebra, and (0.34±0.01) mGy in chest, respectively. There were statistically significant difference in doses among different groups (F=846.826, P<0.05). For different scanning locations, there was linear relation between absorbed dose to eye lens and CTDI(r=0.986-0.999, P<0.05). Conclusions Absorbed dose to eye lens of infants from children CT scaning with single dose may not be above threshold dose. In addition, absorbed dose to eye lens can be estimated quickly by linear regression equation between absorbed dose to eye lens and CTDI.

关 键 词：婴幼儿 CT 眼晶状体 吸收剂量 估算方法 

分 类 号：R814.2[医药卫生—影像医学与核医学]