Parallel OSEM Reconstruction Algorithm for Fully 3-D SPECT on a Beowulf Cluster.
In order to improve the computation speed of ordered subset expectation maximization (OSEM) algorithm for fully 3-D single photon emission computed tomography (SPECT) reconstruction, an experimental beowulf-type cluster was built and several parallel reconstruction schemes were described. We implemented a single-program-multiple-data (SPMD) parallel 3-D OSEM reconstruction algorithm based on message passing interface (MPI) and tested it with combinations of different number of calculating processors and different size of voxel grid in reconstruction (64&#215;64&#215;64 and 128&#215;128&#215;128). Performance of parallelization was evaluated in terms of the speedup factor and parallel efficiency. This parallel implementation methodology is expected to be helpful to make fully 3-D OSEM algorithms more feasible in clinical SPECT studies.
Rong
Zhou
Z
Department of Engineering Physics, Tsinghua University, Beijing, 100084, Email: zhourong00@mails.tsinghua.edu.cn.
Tianyu
Ma
M
Yongjie
Jin
J