摘要
代表身高170 cm、体重65 kg的成年男子躯干(Torso)物理模型经CT扫描获取了其断层信息图像,对这些图像进行组织器官分割、剪切、缩放等处理后,建立了含有200多万个大小为2.73 mm×2.73mm×3 mm的体素的三维体素模型。此体素模型和蒙特卡罗方法结合可用于校准肺部计数器。假定摄入的放射性物质在肺部均匀分布,本文计算了HPGe探测器在模型表面不同位置以及胸壁软组织中不同脂肪质量含量下的计数效率。结果显示,当胸壁软组织中脂肪质量含量由0变为40%,随光子能量变化,肺部计数器计数效率变化程度为:17.5 keV,67%;25 keV,20%。
Tomography images of a Torso phantom was obtained from CT-Scan. The Torso phantom represents the trunk of an adult man that is 170 cm high and weight of 65 kg. After these images were segmented, cropped, and resized, a 3-dimension voxel phantom was created. The voxel phantom includes more than 2 million voxels, which size was 2.73 mm× 2.73 mm × 3 mm. This model could be used for the calibration of hmg counter with Monte Carlo method. On the assumption that radioactive material was homogeneously distributed throughout the lung, counting efficiencies of a HPGe detector in different positions were calculated as Adipose Mass Fraction（AMF） was different in the soft tissue in chest; The resuhs showed that counting efficiencies of the lung counter changed up to 67% for 17.5 keV γ ray and 20% for 25 keV γ my when AMF changed from 0 to 40 %.
出处
《辐射防护》
CAS
CSCD
北大核心
2006年第2期85-92,共8页
Radiation Protection
