人体密度矩阵粗化对剂量计算结果的影响  

Effects Induced by Coarsening Phantom Voxels in Dose Calculations

作　　者：陈炳周[1] 侯氢[1] 

机构地区：[1]四川大学原子核科学技术研究所辐射物理及技术教育部重点实验室

出　　处：《中国医学物理学杂志》2005年第3期497-500,共4页Chinese Journal of Medical Physics

基　　金：国家自然科学基金资助项目(10275045);优秀青年教师资助计划项目

摘　　要：为了提高放射治疗计划中的剂量计算效率,通常要将CT数据给出的密度矩阵作插值运算进行体元粗化。本文用不同的插值方法实现体元粗化,用微分卷积法计算水箱的剂量分布,用DanielA.Low等人眼2演提出的γ参量进行剂量分布的比较,检验了不同射束方向、不同射野尺寸下体元粗化对剂量分布计算值的影响。结果表明:在γ参量意义下体元粗化对剂量分布有明显影响,但对插值方法的选择并不敏感。To improve the computational efficiency in radiotherapy treatment planning, a procedure usually applied is to interpolate the density matrix from CT data of fine voxels to create a density matrix of coarse voxels. In this paper, different interpolation algorithms were used for this procedure and the differential convolution superposition algorithm was used for dose calculations. By applying the parameter proposed by D. A. Low et al[2] for the comparison of dose distributions, we studied the influences of voxel-coarsening procedure mentioned above. The results show that the voxel-coarsening procedure had obvious influence on the dose distributions, however, the results were insensitive to the interpolation algorithm.

关 键 词：密度矩阵 线性插值 微分卷秘积分 剂量比较 

分 类 号：R817.5[医药卫生—影像医学与核医学] O571.33[医药卫生—放射医学]