In vivo measures of tau burden are associated with atrophy in early Braak stage medial temporal lobe regions in amyloid‐negative individuals

Introduction It is unclear the degree to which tau pathology in the medial temporal lobe (MTL) measured by 18F-flortaucipir positron emission tomography relates to MTL subregional atrophy and whether this relationship differs between amyloid-β–positive and amyloid-β–negative individuals. Methods We analyzed correlation of MTL 18F-flortaucipir uptake with MTL subregional atrophy measured with high-resolution magnetic resonance imaging in a region of interest and regional thickness analysis and determined the relationship between memory performance and positron emission tomography and magnetic resonance imaging measures. Results Both groups showed strong correlations between 18F-flortaucipir uptake and atrophy, with similar spatial patterns. Effects in the rhinal cortex recapitulated Braak staging. Correlations of memory recall with atrophy and tracer uptake were observed. Discussion Correlation patterns between tau burden and atrophy in the amyloid-β–negative group mimicking early Braak stages suggests that 18F-flortaucipir is sensitive to tau pathology in primary age-related tauopathy. Correlations of imaging measures with memory performance indicate that this pathology is associated with poorer cognition.