In this study, we used HCI’s for the same cognitively normal late-middle-aged cohort with varying doses of APOE ε4, along with reference data from the AD Neuroimaging Initiative (ADNI) to characterize these individuals, with the aim of determining if this single FDG PET measurement could be used to characterize an association between three levels of genetic risk of AD prior to the onset of symptoms. Here, APOE is linked to Alzheimer disease.