Comparing Bowsher’s Method to MRgBSREM in PET Recon with MR-priors in the Presence of Mismatch Between MRI and PET Images

Motivation: Using MR-priors in PET reconstruction has been performed in numerous studies. While MR-priors provide more SNR and better resolution ti PET-images, without considering motion there may be misalignment between PET and MR images which leads to crosstalk artifacts. Another concern is mismatch between MR and PET images which can potentially affect the final PET image. Goal(s): To compare the two most-widely used PET recon with MR-priors methods: the Bowsher's method and MRgBSREM. Approach: We created an MR-series with severe line artifacts and used in as MR-priors in both methods. Results: We have shown that MRgBSREM handles these mismatches better than the Bowsher’s method. Impact: MRgBSREM is more robust to mismatches between PET and MR. This is achieved by adding a PET-seed image to identify similar-voxels which avoids the situation in which voxels with significantly different PET-uptake would be considered similar based only on MR-images.