Evaluation of [18F]APN-1607 PET Uptake in Alzheimer's Disease Patients Compared With Healthy Subjects

The overall objective of this study is to compare the overall pattern of \[18F\]APN-1607 uptake in subjects with MDAD, subjects with AD dementia, and healthy subjects. The specific objectives are: * To expand the safety and tolerability profile for the administration of \[18F\]APN-1607 and PET scanning. * To assess regional patterns of \[18F\]APN-1607 uptake. * To determine the Braak stage equivalent reflected by \[18F\]APN-1607 uptake patterns. * To evaluate the relationship between regional measures of \[18F\]APN-1607 uptake and demographic characteristics, eg, age and gender; biological characteristics, eg, apolipoprotein E epsilon 4 (APOE4) carrier status and measures of Aβ burden; and clinical characteristics, eg, measurements of AD disease severity, such as National Institute on Aging and Alzheimer's Association (NIA-AA) diagnosis, Mini-mental Status Exam (MMSE) score, and Alzheimer's Disease Assessment Scale-cognitive subscale (ADAScog).