Deep vein diameters and perivascular space scores are associated with deep medullary vein hypo-visibility in patients with white matter hyperintensity.

Background: Deep medullary vein (DMV) hypo-visibility is correlated with white matter hyperintensity (WMH), but the underlying causes remain unclear. This study aimed to explore the relationship between deep vein diameters and perivascular space (PVS) scores, and DMV hypo-visibility in the presence of WMH. Methods: This cross-sectional study prospectively analyzed the clinical and imaging data of 190 cerebral small vessel disease patients with WMH and 40 healthy controls from the Lishui Hospital of Traditional Chinese Medicine affiliated with Zhejiang Chinese Medical University. PVS scores ranging from 0 to 4 were determined according to the PVS counts in the basal ganglia area on T2-weighted magnetic resonance images; high-grade PVS was defined as a PVS score >1. The diameters of the deep cerebral veins, including the bilateral septal veins (SVs), thalamostriate veins (TSVs), lateral ventricular veins (LVVs), and internal cerebral veins, were measured using susceptibility weighted imaging (SWI). Left and right DMV scores, ranging from 0 to 9, were calculated based on the visibility of the DMV on SWI in the ipsilateral frontal, parietal, and occipital lobes. Results: The deep cerebral vein diameters, left and right DMV scores, and high-grade PVS differed between the healthy controls and WMH patients (P<0.05). Left DMV scores were independently associated with age {ß [95% confidence interval (CI)]: 0.050 (0.018, 0.082)}, high-grade PVS [ß (95% CI): 0.998 (0.262, 1.737)], and the diameters of the ipsilateral SVs [ß (95% CI): -1.114 (-1.754, -0.475)], SVs [ß (95% CI): -0.734 (-1.191, -0.277)], and LVVs [ß (95% CI): -0.921 (-1.567, -0.275)] [all false discovery rate (FDR)-corrected P<0.05]. Right DMV scores were independently associated with age [ß (95% CI): 0.071 (0.037, 0.105)], high-grade PVS [ß (95% CI): 0.873 (0.111, 1.635)], and the diameters of the ipsilateral SVs [ß (95% CI): -0.837 (-1.386, -0.289)], TSVs [ß (95% CI): -0.875 (-1.331, -0.419)], and LVVs [ß (95% CI): -1.813 (-2.484, -1.142)] (all FDR-corrected P<0.05). Conclusions: Decreased hypo-visibility of DMVs on SWI was associated with a higher age, the presence of high-grade PVS, and smaller diameters of the ipsilateral deep cerebral veins in individuals with WMH. Our findings provide novel insights into the probable mechanisms leading to high DMV scores.

Impact of Decreased Visibility of Deep Medullary Veins on White Matter Integrity in Patients with Cerebral Small Vessel Disease.

BACKGROUND: Based on susceptibility-weighted imaging (SWI) visibility, deep medullary vein (DMV) scores are related to white matter damage (WMD) in patients with cerebral small vessel disease (CSVD). However, whether mechanisms are associated with DMV changes is unclear. We examined extracellular fluid (ECF) roles in white matter associations between DMV scores and white matter integrity (WMI) in patients with CSVD. METHODS: We examined magnetic resonance imaging (MRI) and clinical data from 140 patients with CSVD. DMV scores (0-18) were assigned on SWI according to DMV anatomic regions and signal continuity/visibility. WMI and ECF volumes were evaluated using free water (FW) and fractional anisotropy (FA) values by diffusion tensor imaging (DTI). RESULTS: DMV scores were independently associated with FA after adjusting for vascular risk factors, age, white matter hyperintensity (WMH) volume, and CSVD burden [ß (95% confidence interval (CI)): -0.219 (-0.375, -0.061), p = 0.006]. We also observed a significant indirect effect of DMV scores on FA in white matter (mediated by FW in white matter) after controlling for age, vascular risk factors, WMH volume, and CSVD burden. CONCLUSIONS: DMV scores were independently related to WMI and mediated by ECF in the white matter of patients with CSVD.

New insights in addressing cerebral small vessel disease: Associated with extracellular fluid in white matter.

Objective: To explore the role of extracellular fluid, assessed by diffusion tensor imaging (DTI) metrics of free water (FW), in the white matter of patients with cerebral small vessel disease (CSVD). Materials and methods: The baseline clinical and imaging data of 129 patients with CSVD were collected and reviewed. CSVD MR markers, including periventricular white matter hyperintensity (PWMH), deep white matter hyperintensity (DWMH), cerebral microbleed (CMB), enlarged perivascular space (PVS), and lacunar infarction (LI), were identified, and CSVD burden was calculated. According to total CSVD MR marker score, cases were classified as mild, moderate, or severe. The mean FW and fractional anisotropy (FA) values were calculated using DTI images. Results: The mean white matter FW was associated with the CSVD MR markers, including PWMH, DWMH, LI and PVS (P < 0.05). Moreover, age, hypertension, diabetes mellitus, and FW value were associated with total CSVD MR marker score (P < 0.05). Ordinal logistic regression analysis revealed that FW and age were independently associated with CSVD burden (P < 0.05). Finally, FW in white matter was associated with FA (r = -0.334, P < 0.001). Conclusion: Extracellular fluid changes, assessed by DTI metrics of FW in white matter, were associated with CSVD markers and burden. An increased extracellular fluid volume in the white matter was associated with lower FA.