A multiscale/multiframe approach to 3D PET data reconstruction

A multiscale/multiframe 3D reconstruction scheme for Positron Emission Tomography is presented. Usually the dimensions of the reconstructed volume or the projection space binning do not change during the image reconstruction process. In this paper we introduce the concept of time frame to the multiscale reconstruction proposed by Raheja et al. This approach can be used for the generation of images reconstructed in near real time using a suitable scale, taking full advantage of list mode reconstruction techniques. When compared with the Maximum Likelihood - Expectation Maximization algorithm (single scale ML-EM), the Multiscale/Multiframe proposed in this work improves the convergence speed in particular in cold regions, as well as performing a fast reconstruction. The generation of different image sequences at different spatial scales and times may be useful to optimize the acquisition clinical protocols on the fly. (orig.)