This study will evaluate imaging characteristics of 18F-AV-1451 in subjects with subacute traumatic brain injury.

TBI Subjects

Inclusion Criteria:

TBI Subjects

• Subjects that have consented and are currently enrolled in either Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI), Evaluation, Pathogenesis, and Outcome of Subjects with or Suspected Traumatic Brain Injury Protocol Number: CNS: 10-N-N122, or Evaluation and Diagnosis of Potential Research Subjects with Traumatic Brain Injury (TBI): Protocol Number: 11-N-0084
• History of having sustained a TBI < 6 weeks prior to enrollment
• Can tolerate PET and MRI scan procedures

Control Subjects

• MMSE ≥ 28
• No significant history of cognitive impairment
• No prior history of TBI
• Can tolerate PET and MRI scan procedures

Exclusion Criteria:

• Have behavior dysfunction that is likely to interfere with imaging
• Are claustrophobic or otherwise unable to tolerate the imaging procedure
• Have current clinically significant cardiovascular disease, or clinically significant abnormalities on screening ECG
• A history of additional risk factors for Torsades de Pointes (TdP) or are taking drugs that are known to cause QT-prolongation
• Have a current clinically significant infectious disease, endocrine or metabolic disease, pulmonary, renal or hepatic impairment, or cancer
• Are females of childbearing potential who are not surgically sterile, not refraining from sexual activity or not using reliable methods of contraception
• Have had a non-study related radiopharmaceutical imaging or treatment procedure within 7 days prior to the 18F-AV-1451 imaging session
• Have current alcohol dependence or alcohol dependence within the past 1 year
• Are currently participating in another interventional clinical trial
• Have evidence of a penetrating brain injury
• Have participated in contact sports in college or after high school age