Kevin C. Chan1,2, Pek-Lan Khong3, Ho-fai Lau1,2, Ed X. Wu1,2
1Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Hong Kong SAR, China; 2Department of Electrical and Electronic Engineering, The University of Hong Kong, Hong Kong SAR, China; 3Department of Diagnostic Radiology, The University of Hong Kong, Hong Kong SAR, China
This study employs in vivo diffusion tensor imaging (DTI) to understand the late changes in white matter (WM) injury and reorganization in the rat brain upon neonatal hypoxic-ischemic cerebral injury. In particular, detailed inspection of the color-encoded fractional anisotropy (FA) map of the principal eigenvector was performed to compare the orientations of the high FA fibers at the perilesional areas with the WM microstructures in the contralateral hemisphere. In addition to the differences in DTI parameters in the microstructures between both hemispheres, results showed that the perilesional areas had similar fiber orientations as the contralateral external capsule in the anterior section of the brain, and as the internal capsule and the fimbria of hippocampus in the posterior section. We demonstrated that DTI can detect the microstructure and orientations of WM fiber changes at the perilesional areas in vivo, and can be used for non-invasive evaluation of HI brain injuries and reorganization.