Evaluation of Inter-reader Reliability Using Images From Subjects With Alzheimer's Disease (AD) or Mild Cognitive Impairment (MCI)

Participants: * Inclusion Criteria AD: * Male or female \>=50 years of age * Meet National Institute of Neurological and Communicative Disorders and Stroke (NINCDS) criteria for probable AD with Mini-Mental State Examination (MMSE) score of 10-24 * Inclusion Criteria MCI: * Male or female \>=50 years of age * Have a Clinical Dementia Rating (CDR) of 0.5 * MMSE \>24 * Exclusion Criteria: * Have a history or current diagnosis of other neurologic disease * Have had or currently have a diagnosis of other neurodegenerative disease * Have participated in experimental therapy targeted to amyloid plaque Readers: •Private nuclear medicine physicians with no prior training in reading florbetapir-PET scans