Association Between Aβ-PET,tau-PET,and Neurodegeneration In MRI With Cognition In Alzheimer’s Disease

Objective: To investigate the associations between imaging biomarkers(β-amyloid(Aβ)PET,tau PET and neurodegeneration in MRI)and cognitive function in Alzheimer’s disease(AD).Methods: 804 subjects with [18F]florbetapir(Aβ)PET,[18F]flortaucipir(tau)PET,structural MRI and neuropsychological assessments from the Alzheimer’s Disease Neuroimaging Initiative were stratified into preclinical,prodromal and AD dementia based on Aβ+/ CDR=0,Aβ+/ CDR=0.5 and Aβ+/CDR≥1 criteria respectively.We examined the associations of 6 regions of interest within the 3 imaging biomarkers and cognitive performances in each group using regression models.Results: 346 preclinical AD,366 prodromal AD and 92 AD dementia subjects were analyzed.In the preclinical AD group,only neurodegenerative changes in MRI but not [18F]florbetapir and [18F]flortaucipir PET were associated with global cognitive and memory performances(range standardized β = 0.128–0.179,p<0.05).In the prodromal AD group,all three imaging biomarkers were associated with worse performances on various neuropsychological tests.In the AD dementia group,both reduced volume of ROIs in MRI and increased [18F]flortaucipir PET uptake were strongly associated with impaired cognitive performances.Conclusions: Both tau-PET and neurodegenerative changes in structural MRI are sensitive imaging biomarkers for cognitive performances in the clinical stages of AD(prodromal and dementia).