Dewaraja Yuni K, Ljungberg Michael, Majumdar Amitava, Bose Abhijit, Koral Kenneth F
Department of Radiology, Division of Nuclear Medicine, The University of Michigan Medical Center, 3480 Kresge III, 204 Zina Pitcher Place, Ann Arbor, MI 48109-0552, USA.
Comput Methods Programs Biomed. 2002 Feb;67(2):115-24. doi: 10.1016/s0169-2607(01)00121-3.
This paper reports the implementation of the SIMIND Monte Carlo code on an IBM SP2 distributed memory parallel computer. Basic aspects of running Monte Carlo particle transport calculations on parallel architectures are described. Our parallelization is based on equally partitioning photons among the processors and uses the Message Passing Interface (MPI) library for interprocessor communication and the Scalable Parallel Random Number Generator (SPRNG) to generate uncorrelated random number streams. These parallelization techniques are also applicable to other distributed memory architectures. A linear increase in computing speed with the number of processors is demonstrated for up to 32 processors. This speed-up is especially significant in Single Photon Emission Computed Tomography (SPECT) simulations involving higher energy photon emitters, where explicit modeling of the phantom and collimator is required. For (131)I, the accuracy of the parallel code is demonstrated by comparing simulated and experimental SPECT images from a heart/thorax phantom. Clinically realistic SPECT simulations using the voxel-man phantom are carried out to assess scatter and attenuation correction.
本文报道了SIMIND蒙特卡罗代码在IBM SP2分布式内存并行计算机上的实现。描述了在并行架构上运行蒙特卡罗粒子输运计算的基本方面。我们的并行化基于在处理器之间平均分配光子,并使用消息传递接口(MPI)库进行处理器间通信,以及使用可扩展并行随机数生成器(SPRNG)生成不相关的随机数流。这些并行化技术也适用于其他分布式内存架构。对于多达32个处理器,展示了计算速度随处理器数量呈线性增加。在涉及高能光子发射体的单光子发射计算机断层扫描(SPECT)模拟中,这种加速尤其显著,在这种模拟中需要对体模和准直器进行显式建模。对于¹³¹I,通过比较来自心脏/胸部体模的模拟和实验SPECT图像,证明了并行代码的准确性。使用体素人模型进行临床逼真的SPECT模拟,以评估散射和衰减校正。