首页 | 本学科首页   官方微博 | 高级检索  
     

用CT值推导人体组织属性参数的方法及改进
引用本文:汤晓斌,陈达,戴耀东,常树全. 用CT值推导人体组织属性参数的方法及改进[J]. 南京航空航天大学学报, 2006, 38(3): 373-377
作者姓名:汤晓斌  陈达  戴耀东  常树全
作者单位:南京航空航天大学材料科学与技术学院,南京,210016;南京航空航天大学材料科学与技术学院,南京,210016;南京航空航天大学材料科学与技术学院,南京,210016;南京航空航天大学材料科学与技术学院,南京,210016
摘    要:蒙特卡罗方法是计算精度最高的人体组织剂量计算方法。常见的蒙特卡罗模拟程序,如M CNP,EG S4等都自带了各种介质的截面数据,而剂量计算的一个重要步骤就是得到人体组织的属性参数——质量密度和化学组成。本文主要介绍了两种根据医学影像CT值推导人体组织属性参数的方法——区间法和两分法,并经过分析比较认为两分法比区间法具有更高的精确度和可行性。同时,针对两分法存在的不足和缺陷,本文将CT值全范围划分为七段,根据两分法的假设条件假设每一段均由两种不同的人体组织混合而成。在每一段CT值范围内,人体组织的质量密度和化学组成通过对两种假定物质参数的拟合得到。结果说明该方法所得到的人体组织属性参数完全可以满足蒙特卡罗人体组织剂量计算的要求。

关 键 词:CT值  组织参数  质量密度  剂量计算
文章编号:1005-2615(2006)03-0373-05
收稿时间:2005-05-10
修稿时间:2005-09-14

Method for Converting CT Numbers into Mass Density and Elemental Weights of Tissue and Its Improvement
Tang Xiaobin,Chen Da,Dai Yaodong,Chang Shuquan. Method for Converting CT Numbers into Mass Density and Elemental Weights of Tissue and Its Improvement[J]. Journal of Nanjing University of Aeronautics & Astronautics, 2006, 38(3): 373-377
Authors:Tang Xiaobin  Chen Da  Dai Yaodong  Chang Shuquan
Affiliation:College of Materials Science and Technology, Nanjing University of Aeronautics Astronautics, Nanjing, 210016, China
Abstract:The Monte Carlo simulation is available to calculate dose distributions in patients with the highest accuracy. To perform the dose calculation with Monte Carlo codes such as MCNP, EGS4 and so on, it is necessary to calculate the mass density and element weights of tissues. Because there is no direct unique relation between CT numbers and tissue parameters, this paper is to describe two methods-multisection and dichotomy methods-to convert CT numbers into the mass density and elemental weights of the tissue. It is known that the dichotomy method is more accurate and practicable compared with the multisection method. Furthermore, the dichotomy method can be improved by seven sections divided on the CT number scale and each confined to two selected tissues. With each section, the mass density and the elemental weight of the selected tissue are interpolated. For this purpose, functional relationships between the CT number and each of the tissue parameters composed of only two components in varying proportions are derived. Compared with conventional data fitness, no loss of accuracy in tissue parameters is accepted when using the interpolation function.
Keywords:CT number  tissue parameters  mass density  dose calculation
本文献已被 CNKI 维普 万方数据 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号