利用蒙特卡罗建模及估算儿童X-CT检查受照剂量

Modeling and dose estimation of pediatric X-CT examination using Monte Carlo technique

在儿科X射线-CT检查迅速增加的当下,尤其对电离辐射敏感的儿童,其所致医疗照射剂量的评估是十分重要和迫切的课题。本文结合已建立的1岁儿童体素体模,利用蒙特卡罗技术建立扫描模型,进行CT检查所致儿童受检者的医疗照射剂量估算。建立了CT单层轴向扫描时对1岁儿童36个器官或组织所产生医疗照射剂量的数据库,利用该数据库,可快速估算1岁儿童受检者接受CT扫描时的医疗照射剂量。并与同样扫描条件下的实验测量值进行了比较,结果显示二者相对偏差在25%以内。

With the rapid development and wide application of X- ray CT examination,estimation of the dose from CT exposures has become a hot research spot,especially for children since they tend to have higher radiation sensitivity than adults. In this work,a CT scanner model was developed using the Monte Carlo technique and was applied to estimate organ doses derived from simulated CT exposures with a 1-year- old voxel phantom developed by our group. As a result,a database including doses to 36 organs and tissues was built for 1- year- old children. This medical exposuredose database provides a method for the estimation of 1- year- old patient doses in a variety of CT examinations. And it has been verified by measurement this method is convenient and reliable.