Plaque vulnerability-specific white matter microstructural integrity loss in asymptomatic carotid atherosclerosis and its link to inflammatory biomarkers: a dual-modality DTI/DKI study

Asymptomatic carotid plaques (ACP) are associated with cerebral microstructural changes, but differential effects of vulnerable (CVP) versus stable plaque (CSP) subtypes remain unclear. This cross-sectional study aimed to characterize plaque subtype-specific white matter (WM) microstructural alterations and explore their relationships with systemic inflammation. Forty-four CVP patients, 15 CSP patients, and 23 healthy controls (HCs) were prospectively enrolled. WM microstructural characteristics were quantified by multi-shell diffusion MRI derived tensor/kurtosis metrics. Inflammation status was measured by serum hs-CRP and IL-6 levels. Both tract-based spatial statistics (TBSS) and region-of-interest (ROI) analyses were performed to identify group differences in diffusion metrics. Pearson correlations were further conducted to investigate the link between diffusion metrics and inflammatory biomarkers. Compared to HCs, the CVP group showed widespread WM microstructural damage, characterized by increased MD/AD/RD and decreased MK/AK in posterior corona radiata and superior longitudinal fasciculus. These abnormalities significantly correlated with elevated hs-CRP and IL-6. The CSP group exhibited few significant WM changes versus HCs. WM microstructural alterations differed between CVP and CSP groups and correlated with elevated inflammatory biomarkers only in the CVP group with higher systemic inflammatory burden, suggesting a potential link among plaque vulnerability, systemic inflammation, and WM microstructural integrity. The dual-modality DTI/DKI approach strengthened the reliability of plaque vulnerability-specific WM microstructural damage in ACP.