PET Imaging Evaluation of [11C]SY08

The overall goal of the proposed research is to evaluate the use of \[11C\]SY08 as a PET radiotracer for aggregated alpha synuclein (αS) in individuals with Parkinson's disease (PD), Multiple system atrophy (MSA), Dementia with Lewy Bodies (DLB) and healthy controls. The purpose of this study is to evaluate the use of \[11C\]SY08 as a PET radiotracer for αS fibrils in individuals with PD, MSA, DLB and healthy controls. The specific aims of the current study are: 1. To determine brain uptake, distribution, and kinetics of \[11C\]SY08 in healthy individuals. 2. To determine brain uptake, distribution, and kinetics of \[11C\]SY08 in patients with alpha synuclein aggregates in the brain, including PD, DLB and MSA. 3. To determine human dosimetry of \[11C\]SY08 in healthy individuals An intravenous bolus injection of \[11C\]SY08 will be administered per subject for brain PET imaging.