White Matter Biomarkers Associated with Motor Change in Individuals with Stroke: A Continuous Theta Burst Stimulation Study

Figure 2

(a, b₁, and b₂) Diffusion tensor imaging. Fractional anisotropy (FA) maps were created for individuals, followed by whole-brain tractography. This is an example of a single subject with a left hemispheric lesion. (a) Regions of interest (ROIs) for the nonlesioned (NL) and lesioned (L) corticospinal tracts (CST) were manually drawn on the native DW image, followed by tractography. The first cross-sectional ROI for the CST was delineated bilaterally (NL-CST and L-CST) in the axial plane [52]. First, a “SEED” ROI was constructed around the PLIC at the level of the anterior commissure [53]. Second, a logical “AND” ROI was constructed around the CST at the level of the mid-pons [54]. The “AND” function constrained the reconstruction to fibers passing through both the “SEED” and “AND” ROI. (b₁) The functional motor network mask (gray ROIs) was extracted and overlaid on the DW MNI image, followed by tractography of the CMC (posterior and anterior views). (b₂) The motor network mask (represented in red) was overlaid on the diffusion-weighted image to create the constrained motor connectome (CMC).