PET Recon with MR Priors: Application in Ambiguously Rated Amyloid PET Scans

Motivation: Uptake in the supratentorial cortex defines clinical amyloid positivity. Because of PET’s low spatial resolution, there is a spill-in effect from adjacent white-matter to gray-matter in amyloid PET scans, which may cause inconsistent rating between trained readers. Goal(s): Reduce the spill-in effect by using MR priors in PET recon to improve the consistency of reading amyloid PET scans. Approach: A recently developed PET recon with MR-priors and motion correction is applied to a set of 18F-florbetaben (amyloid) PET/MRI scans and is compared with regular TOF-OSEM PET recon using SUVR. Results: PET recon with MR priors improves reading of negative amyloid PET scans. Impact: PET-recon with MR-priors can make identifying negative cases more consistent between readers. Given how common inconsistent ratings are for amyloid-PET, methods that improve the ability to distinguish intermediate amyloid levels may be valuable for the widespread use of this modality.