FIG. 1.
Flowchart for the construction of a hemispheric white matter (WM) network by DTI. (1) Individual T1-weighted images were coregistered to the b0 images using a linear transformation. (2) The T1-weighted images were spatially normalized to the T1 template in Montreal Neurological Institute (MNI) space, obtaining the transformation matrix (T). (3) The inversed transformation matrix (T−1) was used to warp the Automated Anatomical Labeling (AAL) atlas in the MNI space to generate the participant-specific AAL mask in the DTI native space. (4) The construction of the DTI from diffusion-weighted images. The color-coded map indicates the directions of the first eigenvectors: red, left to right; green, anterior to posterior; blue, inferior to superior. (5) The reconstruction of all the WM fibers in the whole brain using DTI deterministic tractography. (6) Whole-brain weighted networks were created by computing the mean fractional anisotropy (FA) values of the fiber bundles that connected each pair of AAL regions. (7) Right (R) and left (L) hemispheric networks were obtained by eliminating the interhemispheric connections. Color images available online at www.liebertpub.com/brain