PET成像的加权最小二乘重建算法  

Weighted Least Squares Reconstruction Algorithm for Positron Emission Tomography

作　　者：滕月阳[1] 张铁[1] 

机构地区：[1]东北大学理学院,辽宁沈阳110819

出　　处：《东北大学学报（自然科学版）》2011年第1期10-13,共4页Journal of Northeastern University(Natural Science)

基　　金：国家自然科学基金资助项目(10771031;11071033)

摘　　要：针对正电子发射断层成像系统,提出一种基于加权最小二乘函数的迭代重建算法.与传统的梯度型算法不同,在迭代过程中,此算法利用当前迭代点构造辅助函数,使用辅助函数的最优解代替目标函数的最优解,获得新的迭代点.该算法自动满足非负约束,无需步长因子,保证目标函数单调递减,并且具有全局收敛性.使用模拟数据和真实医学诊断数据进行实验,结果表明:该算法与SA-WLS和ML-EM算法相比需要相同的运算时间,但是具有更快的收敛速度和更好的成像质量.An iterative reconstruction algorithm was developed based on the weighted least squares cost function for positron emission tomography.Unlike the conventional gradient-based algorithm,this algorithm made use of an auxiliary function in the current iterative point to form iteration process,by which the optimal solution was given instead of that by objective function,thus giving the new iterative points.Furthermore,the algorithm automatically satisfied the non-negative constraints of pixels without step size factor required,then ensuring the monotonous decreasing of objective function with global convergence provided.The results of the experiments based on both simulative and real clinical data showed that although the proposed algorithm requires the operating time that is much the same to the SA-WLS and ML-EM,it has higher convergence rate and better imaging quality than the latter.

关 键 词：迭代重建 最小二乘函数 辅助函数 全局收敛 KUHN-TUCKER条件 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]