Quantifying white matter tract diffusion parameters in the presence of increased extra-fiber cellularity and vasogenic edema.

摘要: The effect of extra-fiber structural and pathological components confounding diffusion tensor imaging (DTI) computation was quantitatively investigated using data generated by both Monte-Carlo simulations tissue phantoms. Increased extent vasogenic edema, addition various amount gel to fixed normal mouse trigeminal nerves or increasing non-restricted isotropic in simulations, significantly decreased fractional anisotropy (FA) increased radial diffusivity, while less axial diffusivity derived DTI. cellularity, mimicked graded increase the restricted component FA with limited impact on MC simulation phantom were also analyzed recently developed basis spectrum (DBSI) simultaneously distinguish quantify axon/myelin integrity components. Results showed that cellularity edema did not affect DBSI-derived fiber FA, diffusivity. Importantly, estimated DBSI correlated experimentally added simulations. We examined feasibility applying 25-direction encoding scheme for analysis coherent white matter tracts. from experiments suggested provided comparable estimation parameters cellularity/edema as those 99-direction scheme. An vivo performed experimental autoimmune encephalomyelitis (EAE, an animal model human multiple sclerosis) optic nerve example examine validity post-imaging immunohistochemistry verification. support correctly reflect underlying axonal injury, demyelination, inflammation EAE mice.