Impact of FBB PET Amyloid Imaging in Change of Diagnosis in Patients With AD

It will be conducted in an outpatient setting at the tertiary memory clinics (CMRR) in France in patients with a preliminary diagnosis based on the completion of a prior, full diagnostic workup, not more than 12 months previously - which could include, but will not be limited to brain imaging if needed (magnetic resonance imaging (MRI) or computed tomography (CT)), neuropsychological evaluation including a Mini-Mental Status Examination (MMSE), CSF examination and other examinations according to "Haute Autorité de santé" (HAS, National Authority of Health, France) Recommendations - and in whom: 1. lumbar puncture was not feasible for medical conditions 2. results of cerebrospinal fluid (CSF) analysis were considered ambiguous by treating physicians 3. lumbar puncture (LP) was refused by the patient For all subjects the study will comprise 3 outpatient clinic visits to record information on previous work ups and to perform the FBB Positron Emission Tomography (PET) scan (Visit 1: screening/ baseline, Visit 2: PET scan, Visit 3: subject informed on the FBB PET scan result). At Visit 1, the initial diagnosis based on previous work up will be collected and rated on a five-point Likert confidence scale by the Physician. At Visit 2, the FBB PET scan will be performed. Adverse events will be reported during the exam and up to 7 days after the PET procedure. At Visit 3, based on the amyloid PET scan results, change of diagnosis will be collected, in addition to physician confidence.