In the present study, we aimed at exploring whether the plasma p-tau181: (1) correlated with amyloid PET, tau PET and FDG PET which represented brain neurodegeneration; (2) differentiated between PET status or across clinical diagnosis in AD continuum; (3) could be used as a screening test for detecting abnormal pathological changes in the brain; (4) could predict pathological progression. Here, MAPT is linked to Alzheimer disease.