MAPT and Alzheimer disease: When further dichotomizing preclinical AD based on CSF p‐tau status, significant groups differences were observed in the atrophy rates of all MTL subregions except BA36 between T+ preclinical AD and Aβ− controls with posterior hippocampus (F = 18.7, p = 1.8 × 10−5) and ERC (F = 12.2, p = 3.0 × 10−4) displaying the largest effect size in hippocampus and MTL cortex respectively.