MC法模拟多路平行束准直器对比度  

The Contrast Study of Multi-parallel Beam Collimator by MC Simulation

作　　者：崔浩川 苏为宁[1] 赵经武[1] CUI Hao - chuan SU Wei - ning ZHAO Jing - wu(Physics School of Nanjing University, Nanjing 210093, China)

机构地区：[1]南京大学物理学院,南京210093

出　　处：《核电子学与探测技术》2016年第12期1235-1239,共5页Nuclear Electronics & Detection Technology

摘　　要：采用MC法模拟设计了用于SPECT成像的多路平行束(MPB)准直器,将MPB系统重建的模具图像与平行束(PB)系统重建图像进行对比。用OS-EM迭代算法重建图像并计算对比度、信噪比、归一化标准偏差三个指标用于评价图像质量。结果表明:随着迭代次数增加,MPB系统重建图像中热源的对比度高于PB系统,对于小半径热源这个差值更明显,但是冷源的对比度低于PB系统;两个系统有可比较的重建图像收敛速度,随着迭代次数增加,MPB系统的噪声特性略差于PB系统。A new design of multi - parallel beam collimator is proposed for SPECT imaging by MC simulation. The images obtained by muhi - parallel beam system and parallel beam system are compared in this paper. The OS- EM algorithm is acted on the image reconstruction. Contrast, signal -to- noise ratio and normalized standard deviation are calculated for the image evaluation. The resuhs indicate that, contrasts of hot sources acquired from multi-parallel beam system are bigger than those from parallel beam system which has the same sensitivity as multi - parallel beam system. And the difference of contrasts between two systems is more obvious for hot source with a smaller radius. While the contrasts of cold sources from multi - parallel beam system are smaller than those from parallel beam system. These two systems have a comparable convergence speed of reconstructed image and the noise performance of multi - parallel beam system is slightly worse than that of parallel beam system.

关 键 词：SPECT 多路平行束准直器 OS—EM重建 对比度 

分 类 号：R445.5[医药卫生—影像医学与核医学]