18F-mFBG Cardiac Uptake With Lewy Body Dementia

Inclusion Criteria: * 1\. ≥18 years of age at study entry. 2. Able and willing to comply with study procedures and signed and dated informed consent is obtained. 3\. A male or a female who is either surgically sterile (has had a documented bilateral oophorectomy and/or hysterectomy), postmenopausal (cessation of menses for more than 1 year), non-lactating, or of childbearing potential for whom the result of a serum pregnancy test performed at screening is negative. 4\. All subjects: Judged clinically stable for at least 30 days before enrolment into the study and remains stable to the time of the study imaging procedure. For Lewy body disease subjects (Study Cohort I): 5\. The subject has a diagnosis of either PD or DLB based on accepted clinical criteria at least 6 months before enrollment into the study. For non-Lewy body disease subjects (Study Cohort II): 6\. The subject has a diagnosis of neurological or neurodegenerative disease for which neither PD nor DLB is judged likely by a neurologist based on accepted clinical and imaging criteria. Exclusion Criteria: * 1\. Previously entered into this study or has participated in any other investigational product or medical device study within 30 days of enrollment. 2\. History or suspicion of significant allergic reaction or anaphylaxis to any components of the 18F-mFBG imaging agent. 3\. Presents with any other clinically active, serious, life-threatening disease with a life expectancy of less than 1 year or where participation in the study might compromise the management of the subject or other reason that in the judgment of the investigator(s) makes the subject unsuitable for participation in the study. 4\. Documented ischemic heart disease (prior myocardial infarction, unstable angina, etc) or a diagnosis of heart failure of ischemic or non-ischemic etiology. 5\. Serious non-cardiac medical condition associated with significant elevation of plasma catecholamines including pheochromocytoma. 6\. The subject is claustrophobic or has a movement disorder that prevents him/her from lying still in a supine position for up to 20 minutes. 7\. Renal insufficiency (serum creatinine \>3.0 mg/dL). 8. Uses medications that are known to interfere with uptake of NET-dependent agents and these medications cannot be safely withheld 24 hours before study procedures. 9\. Participated in a research study using ionizing radiation in the previous 12 months such that participation in the study might result in a total effective dose from research procedures exceeding 50 milliSieverts during that time interval.