基于可变形面元模型的新一代人体辐射剂量计算技术

摘要/Abstract

摘要： 为提高人体辐射剂量计算精度,满足精准防护需求,建立了基于可变形面元模型的人体辐射剂量计算技术完整方法,包括人体数字面元模型的变形算法与面元模型高速蒙特卡罗计算方法。其中面元模型的变形采用刚体旋转矩阵、体积图拉普拉斯算子和近似刚体变换三种算法分别实现骨骼、软组织和内部器官的变形;模型高速蒙卡计算则基于Delaunay四面体切割技术。基于此,进行可变形面元模型与不可变形体素模型剂量计算对比试验,结果表明,蹲姿底向照射时,面元模型比直立体素模型得到的有效剂量高51.2%,器官剂量高至98.6%;跪姿前向照射时,面元模型比直立体素模型得到的有效剂量高58.7%,器官剂量高至98.0%。重点突破了新一代剂量计算技术中的面元模型变形、高速蒙特卡罗计算等关键环节,为国内进一步发展高精度剂量计算提供了重要支撑,未来有望在精准防护应用中实现人员剂量的精准评价。

关键词: 辐射剂量, 面元模型, 可变形, 四面体切割, 精准防护

Abstract: In order to improve the accuracy of dose calculation and meet the requirement of precise radiation protection, a complete method of dose calculation based on deformable mesh-type phantom was established, including the deformation algorithm of human mesh-type phantom and the high-speed Monte Carlo calculation method of this phantom. Algorithms of rigid rotation matrix, Laplacian volume map and As-rigid-as-possible transformance were used to deform the bone, soft tissue and internal organs respectively. The high speed Monte Carlo calculation of the phantom is based on Delaunay tetrahedralization technology. Based on this, a comparative test of dose calculation between the deformable mesh-type phantom and the non-deformable voxel phantom was carried out. The results show that, for squatting posture and bottom-up irradiating condition, the effective dose obtained by the mesh-type phantom is 51.2% higher and the organ dose is up to 98.6% higher than that obtained by the voxel phantom; for kneeling posture and antero-posterior irradiating condition, the effective dose obtained by the mesh-type phantom is 58.7% higher and the organ dose is up to 98.0% higher than that obtained by the voxel phantom. This paper focuses on breaking through the key techniques of the new generation of dose calculation technology, including the mesh-type phantom deforming algorithm and high speed Monte Carlo simulation method, which provides important support for the further development of high-precision dose calculation in China. In the future, it is expected to achieve accurate evaluation of personnel dose in precise radiation protection applications.

Key words: radiation dose, mesh-type phantom, deformability, tetrahedralization, precise radiation protection

中图分类号:

TL72

赵日, 刘兆行, 刘娜, 王仙祥, 张静, 梁润成, 刘鑫, 令狐仁静, 戴雨玲. 基于可变形面元模型的新一代人体辐射剂量计算技术[J]. 辐射防护, 2023, 43(6): 533-541.

ZHAO Ri, LIU Zhaoxing, LIU Na, WANG Xianxiang, ZHANG Jing, LIANG Runcheng, LIU Xin, LINGHU Renjing, DAI Yuling. A new generation of human radiation dose calculation technology based on deformable mesh-type phantom[J]. RADIATION PROTECTION, 2023, 43(6): 533-541.

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