Small vessel disease (SVD) accounts for 25% of strokes and is the second most common cause of dementia after Alzheimer's disease. Unlike other causes of stroke, SVD manifests itself years before the stroke by the accumulation of tissue damage. Although heterogeneous, these lesions appear on Magnetic Resonance Imaging (MRI) as white matter hypersignals (WMH). In this context, the ANR SUMMIT project will characterize these lesions in vivo to develop new markers in the early stages of stroke. It is subdivided into 4 work packages, the third one being promoted by CHRU de Tours.