Ahmed Shereen1, Diana Lindquist2, Chia-Yi Kuan3
1Department of Physics, University of Cincinnati, Cincinnati, OH, United States; 2Imaging Research Center, Cincinnati Children's Hospital Medical Center, United States; 3Division of Neurology, Cincinnati Children's Hospital Medical Center
Using diffusion tensor imaging (DTI), we characterized an animal model of leukoaraiosis, a condition caused by chronic hypoxic-hypoperfusion which often leads to post-stroke dementia. We observed radial diffusivity decrease in white matter, contrary to previous findings of increases in radial diffusivity attributed to demyelination after hypoxic-ischemia. Further examination using electron microscopy revealed rapid separation of myelin sheaths and protrusion of myelin-coated vesicles which created multiple intercellular compartments to restrict radial and axial diffusion with minimum change in fractional anisotropy. These results suggest a biophysical mechanism behind leukoaraiosis which may be inferred from unique patterns in DTI metrics.