Exploratory Evaluation of Flortaucipir Injection in Healthy Volunteers and Cognitively Impaired Subjects

Inclusion Criteria: * Healthy volunteers had an Mini-Mental State Examination (MMSE) score of ≥ 29; * MCI due to Alzheimer's disease (AD) consistent with National Institute on Aging (NIA)-Alzheimer's Association working group's on diagnostic guidelines for AD (Alzheimer's Dementia 7:270-9, 2011) * Possible or probable AD: Met clinical criteria for possible or probable AD based on the NIA-Alzheimer's Association working group's on diagnostic guidelines for AD (Alzheimer's Dementia 7:263-9, 2011) Exclusion Criteria: * Current clinically significant psychiatric disease. * Evidence of structural abnormalities such as major stroke or mass on MRI that would have made a diagnosis of impairment due to AD unlikely or was likely to interfere with interpretation of a PET scan on MRI. * Claustrophobic or otherwise unable to tolerate the imaging procedure. * Current clinically significant cardiovascular disease or clinically significant abnormalities on screening electrocardiogram (including, but not limited to, corrected QT interval \>450 msec). * Current clinically significant infectious disease, endocrine or metabolic disease, pulmonary, renal or hepatic impairment, or cancer * History of alcohol abuse or substance abuse or dependence * Female subjects of childbearing potential who were not surgically sterile, not refraining from sexual activity or not using reliable methods of contraception. * Required medications with a narrow therapeutic window * Received a non-study related radiopharmaceutical imaging or treatment procedure within 7 days prior to imaging session * Receiving any investigational medications or had participated in a trial with investigational medications within the last 30 days