Evaluate the Use of [18F]-APN-1607 PET in Subjects With AD-related Cognitive Impairment and Subjects With Normal Cognitive Function

This study is testing a special brain imaging scan called a PET scan that uses a radioactive tracer called [18F]-APN-1607, which attaches to abnormal protein build-ups in the brain linked to Alzheimer's disease. Researchers want to see how well this scan can detect these changes in people with memory problems and people without. **You may be eligible if...** - You are 50 years old or older - You have been diagnosed with normal cognition, mild memory impairment, or Alzheimer's disease - You are able to undergo both brain MRI and PET scans - You are able to understand and sign a consent form - If you are a woman who could become pregnant, you are willing to use reliable contraception during and for 3 months after the study **You may NOT be eligible if...** - You have an atypical form of Alzheimer's disease - You are unable to tolerate MRI or PET scanning - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.