A PARALLEL IMPLEMENTATION OF 3-D CT IMAGE-RECONSTRUCTION ON HYPERCUBE MULTIPROCESSOR

In this paper, we describe how image reconstruction in Computerized Tomography (CT) can be parallelized on a message-passing multiprocessor. In particular, the results obtained from parallel implementation of 3-D CT image reconstruction for parallel beam geometries on the Intel hypercube, iPSC/2, are presented. A two stage pipelining approach is employed for filtering (convolution) and backprojection. The conventional sequential convolution algorithm is modified such that the symmetry of the filter kernel is fully utilized for parallelization. In the backprojection stage, the 3-D Incremental algorithm, our recently developed backprojection scheme which is shown to be faster than conventional algorithm, is parallelized. The speed-up, defined as (sequential processing time)/(parallel processing time), ranging from 5 to 27, and the efficiency, defined as (speed-up)/(the number of processing elements), ranging from 60% to 92%, have been achieved, depending on the size of image and the number of processing elements employed. © 1990 IEEE