Cortical thickness for the AD signature is the mean of the thickness (in mm) of the following cortical regions from the two hemispheres: middle temporal and inferior temporal, entorhinal, temporal pole, fusiform, superior frontal, rostral and caudal middle frontal, superior and inferior parietal, supramarginal, and precuneus. When the measurement of the thickness of a region in one of the two hemispheres is rejected during quality checks, then only the thickness of a region in one of the two hemispheres is used.