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Parallel Methods for the Reconstruction of SPECT Images

Single photon emission computed tomography (SPECT) has become an important diagnostic tool in nuclear medicine, because of the important clinical role that it can offer. Reconstruction methods are necessary to compensate several effects that severely degrade the quality of the image. All reconstruction methods are computationally very intensive, and require several hours. A reduction by several orders of magnitude is indispensable for 3-D reconstruction and clinical use. In this paper we analyze the parallelism contained respectively in the projection/backprojection operations, and the EM iterative method. While the analysis of the former showed too fine grained parallelism, we were able to achieve a satisfactory reduction in time with the parallel implementation of the latter on a cluster of work-stations.