Gray to white matter signal ratio (GWR) as a novel MRI‐based biomarker of longitudinal cognitive decline in older adults with and without amyloid pathology

In cognitively normal older adults, GWR at baseline is sensitive to early microstructural neurodegenerative change that predicts the rate of subsequent cognitive decline. Our findings support the utility of conventional T1-weighted MRI for multi-scale assessment of brain structural integrity, with potential applications in diagnosis, prognostication, and outcomes monitoring in neurodegenerative diseases.