THE FAVOR ALGORITHM FOR 3D PET DATA AND ITS IMPLEMENTATION USING A NETWORK OF TRANSPUTERS

The recent appearance of septa-retractable positron emission tomograph y (PET) scanners has created a demand for fast three-dimensional (3D) reconstruction. While algorithms based on filtered backprojection have been developed to reconstruct PET data acquired in 3D (volume mode), they are computationally intensive owing to the large numbers of coinc idence lines and image voxels that must be processed. Such linear algo rithms are well suited to parallel implementation on a network of indi vidual processors. In this paper, we present an algorithm for fast vol ume reconstruction (FAVOR) of PET data, and describe its parallel impl ementation on a network of 44 T800 transputers. A reconstruction time of 1200 s has been achieved with this configuration of 44 T800 transpu ters comparable to that required by a single i860 processor. The prosp ects exist for 3D reconstruction times of around 120 s with the new ge neration of T9000 transputers which should become available in the nea r future.