GE Healthcare, Uppsala, Sweden GE Healthcare, Amersham, UK KU Leuven, Leuven, Belgium CRC/University of Liege, Liege, Belgium Rigshospitalet, Copenhagen, Denmark Imperial College London, London, UK GE Healthcare, Amersham, UK Purpose: The PET ligand [F]flutemetamol is structurally identical to [C]PiB, apart from the radioisotope, and is being developed as a biomarker for detection of fibrillar β amyloid (Aβ) aggregates, one of the pathological hallmarks of Alzheimer's disease (AD). The objective of this study was to examine how well the regional cerebral-to-cerebellum standardized uptake value ratio (SUVR) from a [F]flutemetamol PET scan allowed to separate subjects with probable AD from healthy volunteers (HV), as well as to assign patients with mild cognitive impairment (MCI) to categories of either raised or low levels of Aβ. In addition, this quantitative classification was compared with the categorization achieved by means of visual assessment.