[18F]AV-45 was studied in a total of 16 HC volunteers and 16 AD patients. Patients with AD had to be greater than 50 years of age and have a probable diagnosis of AD according to the NINCDS-ADRDA, with a Mini-Mental State Examination (MMSE) score between 10 and 24 inclusive. (12 (link), 13 (link)) HC subjects had to be greater than 50 years of age, with no evidence of cognitive impairment by history and psychometric testing, and had to have an MMSE score of ≥ 29. Subjects who showed evidence of any other significant neurodegenerative or psychiatric disease on clinical examination or MRI, or clinically significant medical comorbidities that might pose a safety risk to the subject or interfere with interpretation of the scan were excluded from the study. Patients with AD could be on a stable dose (by investigator judgment: not in titration period, no change in medication being considered) of an acetylcholinesterase inhibitor, memantine, and/or Vitamin E. Patients who had ever participated in an experimental study with a treatment targeting amyloid (e.g., immunotherapy, secretase inhibitor, selective amyloid lowering agents) were excluded. All procedures were approved by the appropriate Institutional Review Board and all participants or an appropriate representative signed informed consent forms, consistent with established criteria (12 (link)).
Similar acquisition protocols were used at the three centers. All subjects received a single IV bolus of approximately 370 MBq or 10 mCi [18F]AV-45 and PET imaging began. Dynamic brain PET images were collected for a period of approximately 90 minutes. The PET scanners employed were GE Advance (PET only, at JHU), GE Discovery LS (PET/CT), at CHC and MEC, and the Discovery ST (PET/CT), at MEC). In addition plasma metabolite analysis was conducted using the method of Hilton, et al (14 (link)). For detailed PET, metabolite analysis and image acquisition procedures see supplementary information.