基于优化子集顺序的三维OSEM图像重建算法  

Three Dimensional OSEM Image Reconstruction Algorithm Based Optimizing Subset Order

作　　者：孔慧华[1] 潘晋孝[1] 吴琨[1] 

机构地区：[1]中北大学理学院,山西太原030051

出　　处：《测试技术学报》2011年第2期168-172,共5页Journal of Test and Measurement Technology

基　　金：国家自然科学基金资助项目(60772102;60876077;61071193);山西省自然科学基金资助项目(20090110183;2010011002-1;2010011002-2)

摘　　要：在有序子集算法中,大的子集个数可以加速算法的收敛,但重建图像的质量也会受到影响.为了加速OSEM算法的收敛速度,提高重建图像的质量,本文提出一种优化子集顺序的方法,该方法不仅考虑了子集间的几何相关性,还能使已选用的子集在几何上尽可能地分布均匀.实验选取3-D Shepp-Logan模型作为测试模型,并且从数量上和质量上对重建图像进行分析,结果表明,所提出的算法不仅收敛速度快,还可以减小因增大子集个数对重建图像质量造成的影响.In OSEM algorithm, using a number of subsets can accelerate convergence of the algorithm, but the quality of the reconstructed images might be affected. In order to accelerate the convergence of OSEM and improve the reconstruction quality, an optimized subset ordering scheme is proposed in this paper. The new method not only considers the correlation between the adjacent subsets but also guarantees that the selected subsets are distributed evenly as possible in geometry. The 3D Shepp-Logan model is selected as the test ob- ject. Both qualitative and quantitative measurements are used to evaluate the proposed method in this study. Results show that the new method is faster than the classical OSEM and it still can decrease the impact on the image quality when increasing the number of subsets.

关 键 词：图像重建 OSEM算法 优化子集顺序 收敛速度 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]