PMC

Box plots of FA-(upper) and MD-(lower) weighted WM connectivity between patients with and without cortical CMIs (labels) clinical diagnosis (X-axis). MD values × 10⁻³ mm²/s. CMI, Cortical microinfarct; NOCI, No objective cognitive impairment; MCI, Mild cognitive impairment; AD, Alzheimer's disease; VaD, Vascular dementia.

3D representation of the spatial distribution of cortical microinfarcts (CMIs; represented as black dots) across the brain in the cohort. The red areas represent the Automated Anatomical Labeling (AAL)-atlas regions with a high CMI burden (i.e., the 7 brain regions which contained 75% of all the cortical CMIs).

Overview of workflow. In the top panel (network-based approach): from a patients' DTI images (A), WM connections are reconstructed using fiber tractography (B). Next, brain network nodes were defined using the cortical parcellation using the AAL template (C). Subsequently, the structural brain network was reconstructed (D). Weighting of the network was done by multiplying each connection by the mean fractional anisotropy (FA) or mean diffusivity (MD). Finally, the mean FA and MD of connections towards high and low cortical microinfarcts (CMI) burden regions were compared between patients with and without CMIs. In the bottom panel (voxel-based approach), the patient's DTI image A) is combined with the patient's WM segmentation results (E) and AAL template (F) to assess diffusion properties of the WM voxels in the AAL region (i.e. directly underneath the cortex) (G).