Inclusion Criteria: 

• Ability to provide signed informed consent (with or without Legal authorized representative, as appropriate) and willingness to comply with protocol requirements
  
• Male or female 60-90 years of age
  
• Documentation of clinical diagnosis of one or more of the following: subjective memory complaints, mild cognitive impairment, Alzheimer’s Disease

Exclusion Criteria: 

• A questionnaire-based screen reveals confounding neurological disease, or the MRI over-read by staff radiologists reveals the same
• Neurological co-morbidities unrelated to neurodegeneration, including, but not limited to stroke, hydrocephalus or epilepsy
• Gene variation that would inhibit binding to study drug (DPA713) and/or clinical factors that would compromise statistical analysis of the PET
• Any metal in the body above the waist, claustrophobia, unlikely to remain still during examinations or other contraindication for MRI (i.e. ferromagnetic implants, pace-maker, etc.) 
• Other unspecified reasons that, in the opinion of investigators, make the subject unsuitable for enrollment