Increased visibility of deep medullary veins in leukoaraiosis: a 3-T MRI study

Abstract

Cerebral venous collagenosis has been implicated in leading to white matter hyperintensities (WMHs) via venous ischemia. We sought to determine whether cerebral venous dilation or ischemia correlate with the severity of WMHs by quantitative in vivo imaging techniques. This was an investigator-initiated prospective single-center study. We reviewed clinical, laboratory data from 158 consecutive WMHs patients and 50 controls, and measured the number of voxels of deep medullary veins (DMVs) on susceptibility-weighted image and assessed the WMH volume (as a marker of the severity of WMHs) on a 3-T magnetic resonance system. We then performed the logistic-regression analysis and partial Pearson's correlation analysis to examine the association between the venous voxel count and WMH volume. The number of voxels of DMVs was significantly higher in WMHs than in controls. Increased number of voxels of DMVs was independently associated with both WMH volume of the whole brain and coregistered regional WMH volume after adjusting for age and number of lacunes. Our study indicates that cerebral deep venous insufficiency or ischemia play a role in the pathogenesis of WMHs, which may provide prognostic information on patients with WMHs and may have implications for therapeutic interventions.

Keywords: aging; deep medullary veins; leukoaraiosis; susceptibility-weighted imaging; venous ischemia; white matter hyperintensities.

Figure 1

Axial T2 fluid attenuated inversion recovery (FLAIR) images were coregistered to the phase images. (A) T2 FLAIR image; (B) phase image of the same patient was set as a reference; (C) coregistered T2 FLAIR image.

Figure 2

Image post-processing and segmentation of the deep medullary venous structures were based on filtered phase images. (A) A filtered phase slice of one WMH patient; (B) the same slice after segmentation used to calculate the number of voxels of the deep medullary veins for quantification.

Figure 3

The scatter plots between log-transformed corrected white matter hyperintensity (WMH) volume and number of the deep medullary venous voxels. Partial Pearson’s correlation analysis was used by adjusting for age, sex, years of education, and number of microbleeds and lacunes. (A) The correlation between voxel count and WMH volume of the whole brain. (B) The correlation between voxel count and the regional WMH volume.

Figure 4

Fluid attenuated inversion recovery images (A,C) and SWI phase images (B,D) of two (white matter hyperintensity) WMH patients. The corrected white matter hyperintensity volume was 82.66 ml (C) and 16.88 ml (A). Number of voxels of the deep medullary veins was increased (4897 vs. 2782) in the severe WMH patient (D), compared with mild WMH patient (B).