This study is designed to expand the database of flortaucipir F 18 safety and tau binding as measured by PET imaging and to provide standardized conditions for flortaucipir PET use, data collection and analysis to facilitate companion studies including, but not limited to, longitudinal studies of aging, depression, and traumatic brain injury.

Subjects should meet inclusion and exclusion criteria for the companion protocol in addition to the criteria below.

Inclusion Criteria:

• Subjects who have a historical volumetric magnetic resonance imaging (MRI) as part of the companion study

Exclusion Criteria:

• Have clinically significant cardiac, hepatic, renal, pulmonary, metabolic, or endocrine disturbances
• Have a screening electrocardiogram with a corrected QT interval (QTc) > 450 msec if male or QTc > 470 msec if female
• Have a history of additional risk factors for Torsades de Pointes (TdP) or are taking drugs known to cause QT-prolongation. Patients with a prolonged QTc interval in the setting of intraventricular conduction block may be enrolled with sponsor approval
• Have a history of drug or alcohol dependence within the last year, or prior prolonged history of dependence unless approved by the sponsor
• Are females of childbearing potential who are not surgically sterile, not refraining from sexual activity or not using reliable methods of contraception
• Have a history of relevant severe drug allergy or hypersensitivity
• Are patients who have received an investigational medication within 30 days prior to the planned imaging session for this study
• Are patients with current clinically significant unstable medical comorbidities
• Are patients who have received a radiopharmaceutical for imaging or therapy within the past 24 hours prior to the imaging session for this study

AEs were collected at scan visit and for 48 hours after flortaucipir administration.

AEs defined as occurring or worsening after injection, within 48 hours, at an imaging visit. AEs occurring after administration, but outside that window were not reported, unless considered attributable to study drug. Note: AE results differ from results reported above because this section reports ALL adverse events, regardless of investigator's designation of relatedness.