ISBN:  Unavailable

Category: Unavailable

Page count: 27

Abstract: "PET reconstruction by the EM algorithm is an iterative computation of Poisson emission rates to maximize a likelihood function. The method is time-consuming and, for real scanner data, requires large numerical arrays. To speed up the computation on multiple processors which have their own local memory and communicate by passing messages on a network, a parallel method has been implemented in which processors compute several iterations before exchanging their latest data with other processors. This method is convenient for iterative reconstruction using a relatively small number of standard workstations on a local area network, i.e., for implementation on computer resources commonly available in clinical and research environments and for which reducing communication among processors is desirable. Computational aspects of the method are explained and illustrated with 2-D reconstructions from a simulation and from sinograms produced by a PET scanner. 512 iterations are computed on a local area network of workstations and, for reference, on a distributed- memory multiprocessor computer as well. The method is capable of producing high quality reconstructions with significant speed-up."