The National Institute on Aging together with the Alzheimer's Association (NIA-AA) recently proposed the ATN classification which is based upon the pathological processes present in Alzheimer's disease (amyloid, tau and neurodegeneration). The amyloid and tau status can be defined using cerebrospinal fluid analysis but also non-invasively using an amyloid or tau PET scan. The N status can be defined using an \[18F\]-FDG PET scan which is in Belgium part of standard of care. Recently, it has been demonstrated, using different amyloid PET tracers, that early-frame amyloid scans can be a surrogate for \[18F\]-FDG PET scan.