Evaluation of [18F]MK-9470 as a Brain Tracer of Cannabinoid-1 Receptor in Parkinson's Disease and Healthy Subjects

Early PD Subjects Inclusion criteria: * The participant is 30 years or older. * Written informed consent is obtained. * Participants have a diagnosis of PD (based on UK Brain Bank Criteria) within the past 2 years. * Modified Hoehn and Yahr stages 1-2. * No evidence of dyskinesia by history or clinical examination * For females, non-child bearing potential or a negative urine or blood pregnancy test on day of \[18F\]-MK-9470 injection. Advanced PD subjects Inclusion criteria: * The participant is 30 years or older. * Written informed consent is obtained. * Participants have a diagnosis of PD (based on UK Brain Bank Criteria) of at least 5 years duration. * Modified Hoehn and Yahr stages 1-4. * No evidence of dyskinesia by history or clinical examination * For females, non-child bearing potential or a negative urine or blood pregnancy test on day of \[18F\]-MK-9470 injection. Subjects who have a clinical diagnosis of advanced PD with dyskinesia will be recruited for this study. ePD subjects Inclusion criteria: * The participant is 30 years or older. * Written informed consent is obtained. * Participants have a diagnosis of PD (based on UK Brain Bank Criteria) of at least 5 years. * Modified Hoehn and Yahr stages 1-4. * Evidence of dyskinesia either by history or clinical examination * For females, non-child bearing potential or a negative urine or blood pregnancy test on day of \[18F\]-MK-9470 injection. PD (all stages- e-PD, aPD, aPD-dys)Subject Selection. Subjects who have a clinical diagnosis of ePD, aPD, aPD-dys will be recruited for this study. All PD subjects Exclusion criteria: * The subject has a clinically significant abnormal laboratory value and/or clinically significant unstable medical or psychiatric illness * The subject has any disorder that may interfere with drug absorption, distribution, metabolism, or excretion. * The patient has evidence of unstable gastrointestinal, cardiovascular, hepatic, renal, hematological, neoplastic, endocrine, neurological, pulmonary, or other disorder or disease. * Evidence of a stroke or mass lesion in a clinically relevant area that may interfere with the imaging outcome measure * Subjects with radiation exposure above acceptable levels * Pregnancy Healthy Control Subject Selection: subjects who have no neurological disease will be recruited for this study. Healthy control subjects Inclusion criteria: * The participant is 18 years or older. * Written informed consent is obtained. * Negative history of neurological or psychiatric illness based on evaluation by a research physician. * For females, non-child bearing potential a negative urine or blood pregnancy test on day of \[18F\]-MK9470 injection. Exclusion criteria: * The subject has a clinically significant abnormal laboratory value and/or clinically significant unstable medical or psychiatric illness. * The subject has evidence of clinically significant gastrointestinal, cardiovascular, hepatic, renal, hematological, neoplastic, endocrine, neurological, immunodeficiency, pulmonary, or other disorder or disease. * The subject has any disorder that may interfere with drug absorption, distribution, metabolism, or excretion. * Subjects with radiation exposure above acceptable levels * Pregnancy