Decreased Visibility of Deep Medullary Vein Associated with Cerebral Small Vessel Disease Burden through Increased Interstitial Fluid in White Matter

Decreased visibility of deep medullary veins (DMVs) on susceptibility-weighted imaging (SWI) has been reported in individuals with cerebral small vessel disease (CSVD). This study aims to explore the relationship between the decreased visibility of the DMV, interstitial fluid (ISF), and the CSVD burden. Patients with CSVD (n = 128) were enrolled with multimode MRI. The DMV score was used to score visibility of DMVs on SWI. ISF was evaluated by mean free water (FW) on diffusion tensor imaging in white matter. CSVD burden was evaluated, including the severity of each CSVD marker at MRI and total CSVD MR score. The DMV score was associated with the severity of each CSVD imaging marker and total CSVD MR score (P < .05). Further, the indirect effect of the DMV score on the severity of CSVD imaging makers [white matter hyperintensity (WMH), cerebral microbleed (CMB) and lacunar infarct (LI)] and total CSVD MR score mediated by FW was significant [WMH: β, 95% CI: 0.13 (0.05, 0.24); LI: β, 95% CI: 0.19 (0.06, 0.32); CMB: β, 95% CI: 0.13 (0.01, 0.30); total CSVD MR score: β, 95% CI: 0.16 (0.05, 0.29)] controlling with age and vascular risk factors. The DMV score was associated with the CSVD burden through FW in white matter in individuals with CSVD and may describe a venous aspect of the pathogenesis of the CSVD burden.