MAPT and Alzheimer disease: Diffusivity in the hippocampus has also been correlated with tau burden as a continuous measure of disease pathology, cognitive scores with tasks dependent on hippocampal function, and glucose metabolism in AD (Chen et al., 2022; Hong et al., 2012; Shahid et al., 2022; Yakushev et al., 2010; Fellgiebel & Yakushev, 2011).