Tracking early cognitive decline in preclinical AD with brain MRI similarity

Brain similarity captures early brain changes in preclinical Alzheimer's disease (AD). Brain similarity outperforms conventional biomarkers such as cortical thickness, volume measures, and fluid biomarkers in predicting cognitive decline. Brain similarity predicts conversion to mild cognitive impairment and AD more accurately than traditional imaging markers, and its predictive performance is further improved when combined with fluid biomarkers. Brain similarity captures structural disruptions associated with cortical layer II of the cytoarchitectonic lamina of human neocortex.