Quantification of Amyloid in the Piriform Cortex in Alzheimer’s and Parkinson’s Disease using PET-MR

Motivation: Olfactory dysfunction may be an early indicator of Alzheimer's disease (AD), but it remains unclear whether amyloid pathology in AD affects the primary olfactory piriform cortex. Goal(s): To compare piriform cortex uptake to the adjacent medial temporal lobe across the progression of AD pathology using amyloid and tau PET-MR. Approach: Using 18F-Florbetaben/PI-2620 PET-MR, we computed piriform and medial temporal amyloid/tau uptake in AD, mild cognitive impairment, amyloid negative/positive controls, and Parkinson's disease (PD). Results: Piriform amyloid was positively associated with increasing disease status. Amyloid and tau uptake were positively correlated, while amyloid and memory scores were negatively correlated. Impact: We show amyloid uptake in the piriform cortex as well as other medial temporal regions, including the entorhinal-perirhinal cortices. These results further enrich the scientific understanding of the role of the piriform cortex in the progression of early AD.