Overview

1. To evaluate the diagnostic performance of \[18F\]-APN-1607 injection PET imaging in detecting uptake patterns consistent with AD neuropathological changes as defined by the National Institute on Aging-Alzheimer's Association (NIA-AA) criteria.
2. To assess the association between \[18F\]-APN-1607 injection and Alzheimer's disease (AD)-related tau neurofibrillary pathology (as determined by post-mortem brain tissue histopathology), and detect the uptake pattern corresponding to neurofibrillary tangle (NFT) scores.
3. To evaluate the safety of \[18F\]-APN-1607 injection.

Eligibility

Inclusion Criteria:

1. Able to understand and voluntarily sign a written informed consent form (ICF).
2. Age≥50 years, male or female.
3. Charlson Comorbidity Index (CCI)≥5.
4. Able to tolerate imaging procedures.
5. For MCI or AD subjects: clinically diagnosed as AD-derived cognitive impairment or Alzheimer's dementia.
6. For HV subjects: no known personal or family history of AD-derived dementia.

Exclusion Criteria:

1. Confirmed brain structural abnormalities that may affect PET reading, e.g., large stroke (infarct area\>4 cm) or intracranial space-occupying lesion.
2. Currently having clinically significant infectious diseases: HIV, hepatitis, etc.
3. Currently participating in any investigational clinical trial.
4. Previous participation in clinical studies of amyloid or tau-targeting agents.
5. Suspected hepatic encephalopathy.
6. Allergy to the investigational drug or any of its components.
7. Currently pregnant or breastfeeding.
8. Currently having a disease or condition that prolongs the QT interval.