Comparing brain scans that show different levels of detail

Inclusion Criteria: 1. Participants over the age of 18 who are enrolled in the PPMI Clinical protocol with a diagnosis of Parkinson's disease (PD) or Healthy Control participants enrolled in the PPMI Clinical protocol. 2. Able to provide informed consent. 3. Male or Female (females must meet additional criteria specified below as applicable) 1. Females must be of non-childbearing potential or using a highly effective method of birth control 14 days prior to until at least 24 hours after 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 PET scan) 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. 2. Females of childbearing potential must not be pregnant, breastfeeding or lactating. * Includes a negative urine pregnancy test prior to injection of \[18F\]AV-133 on day of PET scan. 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. Any other medical or psychiatric condition or lab abnormality, which in the opinion of the investigator might preclude participation.