Imaging Characteristics of Florbetapir 18F in Patients With Frontotemporal Dementia, Alzheimer's Disease and Normal Controls.

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 and have a Mini Mental State Examination (MMSE) score at screening between 10 and 24 inclusive * Have a caregiver who can report on their mental status and activities of daily living (ADL) * Give informed consent or have a caregiver give consent with subject assent. FTD: * Male or female \>= 45 years of age * Meet consensus criteria for FTD and have mild to moderate disease severity. Have a caregiver who can report on their mental status and ADL * Give informed consent or have a caregiver give consent with subject assent. CN: * Male or female \>= 45 years of age * Have and MMSE \>= 29 * Give informed consent Exclusion Criteria: * Have a history or a current clinically significant neurologic disease (other than AD or FTD, as applicable), a diagnosis of other dementing/neurodegenerative disease, or a diagnosis of mixed dementia * Evidence from MRI or other biomarkers that suggests an etiology of dementia other than AD or FTD, as applicable or in the case of CN subjects evidence indicating the presence of AD, FTD or other types of neurologic pathology * Have current clinically significant cardiovascular disease, screening ECG abnormalities, psychiatric disease, endocrine or metabolic disease, pulmonary, renal or hepatic impairment, cancer or infectious disease * Have a recent history of alcohol or substance abuse or dependence * Women of childbearing potential who are not permanently surgically sterile, or are not refraining from sexual activity while not using adequate contraception. * Require medications with a narrow therapeutic window, are receiving any investigational medications, or have participated in a trial with investigational medications within the last 30 days * Have ever participated in a study with an amyloid targeting agent * Have had a radiopharmaceutical imaging or treatment procedure within 7 days of the imaging, other than as defined in the protocol