APOE and memory impairment: Although another study suggested no significant difference in hippocampal volume atrophy between Alzheimer’s disease and behavioral variant frontotemporal dementia [59], our results showed that MTA could be an essential predictor of Aβ positivity in aMCI patients, if the clinical phenotypes such as age, memory impairment, and the presence of APOE ε4 allele were combined for prediction.