Voxel-based correlation of (18)F-THK5351 accumulation with gray matter structural networks in cognitively normal older adults

OBJECTIVE: The aim of this study was to evaluate tau-related structural network metrics derived from gray matter magnetic resonance imaging (MRI) scans in cognitively normal (CN) older adults. METHODS: We recruited 47 amyloid-negative CN older adults (mean age ± standard deviation, 65.0 ± 7.9 years; 26 women). All participants underwent 3D T1-weighted MRI and (11)C-Pittsburgh compound-B and (18)F-THK5351 positron emission tomography scans. Four local network metrics (betweenness centrality, clustering coefficient, characteristic path length, and degree) were computed and rendered on individual brain images. We then evaluated the correlations between (18)F-THK5351 positron emission tomography images and local network metric images at the voxel level. RESULTS: Significant positive correlations of the four local network metrics with (18)F-THK5351 were detected in the bilateral caudate. CONCLUSION: Our findings suggest that tau and neuroinflammation in CN older adults may influence the gray matter structural network in the caudate.