Microstructure fingerprints of white matter hyperintensities in the aging brain

Motivation: Cerebral small vessel disease is a major contributor to age-related lacunar stroke and cognitive decline, often identified as white matter hyperintensities (WMH) on MRI scans. Goal(s): This study uses FLAIR-based WMH segmentation to define lesion location and extent, integrating diffusion and qMRI metrics to characterize WMH heterogeneity and microstructural fingerprint. Approach: We used advanced imaging metrics to assess the microstructural integrity of WMHs, focusing on fluid content and cellular structure. Results: WMHs show reduced myelin, cell density, and increased fluid, particularly in periventricular regions. Layer-specific analyses reveal damage extending beyond WMH boundaries. BMI and hypertension are linked to greater white matter degeneration. Impact: This study offers unique insights into white matter hyperintensities (WMH), demonstrating characteristic patterns of myelin and axonal loss. Our findings highlight the importance of advanced imaging techniques to better understand the complexities of WMH and their impact on brain health.