MAPT and Cognitive impairment: In this study, we characterized regional tau deposition by PVC-based 18F-AV1451 PET imaging in cognitively normal older adults (CN), mild cognitive impairment (MCI) and AD participants, and evaluated the correlations between CSF biomarkers or Mini-Mental State Examination (MMSE) and 18F-AV1451 PET standardized uptake value ratio (SUVR).