Early Longitudinal Imaging in Parkinson's Progression Markers Initiative Using [¹⁸F] AV-133 and DaTscan™

Inclusion Criteria: 1. A PD participant consented to PPMI Clinical, or, a Prodromal participant confirmed eligible to proceed to PPMI Clinical Baseline visit. 2. Able to provide informed consent. 3. Women may not be pregnant, lactating or planning pregnancy during the study. * Includes a negative serum pregnancy test prior to Baseline 18F-AV-133 injection. * Includes a negative urine pregnancy test prior to injection of 18F-AV-133 on day of Baseline PET scan. * Women participating in the study must be of non-childbearing potential or be using a highly effective method of birth control 14 days prior to until at least 24 hours after the last injection of 18F-AV-133. * Non-childbearing potential is defined as a female that must be either postmenopausal (no menses for at least 12 months prior to Screening) or surgically sterile (bilateral tubal ligation, bilateral oophorectomy or hysterectomy). * Highly effective method of birth control is defined as practicing at least one of the following: A birth control method that results in a less than 1% per year failure rate when used consistently and correctly, such as oral contraceptives for at least 3 months prior to injection, an intrauterine device (IUD) for at least 2 months prior to injection, or barrier methods, e.g., diaphragm or combination condom and spermicide. Periodic abstinence (e.g. calendar, ovulation, symptothermal, post-ovulation methods) is not acceptable. Exclusion Criteria: 1. Received any of the following medications that might interfere with 18F- AV-133 PET imaging: tetrabenazine (TBZ) or methylphenidate, reserpine, or amphetamine derivative, within 1 month prior to the Baseline 18F-AV-133 injection. 2. Have current clinically significant cardiovascular disease or abnormalities on screening ECG (including but not limited to QTc \> 450 msec). 3. Are currently taking medications that are known to cause QT- prolongation 4. Any other medical or psychiatric condition or lab abnormality, which in the opinion of the investigator might preclude participation.