Fig. 1.

Sample size flow chart of different stages. All subjects underwent CSF examination and amyloid PET scan on step 2, except for 12 subjects who withdrew from undergoing the amyloid PET scan. AD, Alzheimer's disease; aMCI, amnestic mild cognitive impairment; CSF, cerebrospinal fluid; DLB, dementia with Lewy bodies; FTD_SD, semantic variants of frontotemporal dementia; MCI, mild cognitive impairment; naMCI, nonamnestic mild cognitive impairment; NPH, normal-pressure hydrocephalus; NR, normal; PET, positron emission tomography.