MRP approaches to PET image reconstruction

The purpose of this study is to introduce a novel empirical iterative algorithm for medical image reconstruction, under the short name MRP-ISWLS (Median Root Prior Image Space Weighted Least Squares). We use phantom data from a prototype small-animal PET system and the methods presented here are applied to 2D sinograms. Further, we assess the performance of the new algorithm by comparing it to the simultaneous version of MRP-EM-ML (Median Root Prior Expectation Maximization Maximum Likelihood). Both algorithms are compared in terms of reconstruction time and CNRs (Contrast-to-Noise Ratios). As it turns out, MRP-ISWLS presents higher CNRs than MRP-EM-ML for objects of different size. Also MRP-ISWLS has better noise manipulation.