Abstract:
HTML
Purpose: Recent studies have demonstrated the potential clinical utility of diffusion tenor imaging (DTI) in revealing micro-structural alterations in white matter in patients with neurodegenerative disease. However, histological confirmations of that observed in DTI are lacking. To this end, murine models of demyelination diseases, such as Cuprizone mice, are often utilized to evaluate the demyelination and remyelination process in neural white matter. Therefore, the goal of this study is to employ the animal model of demyelination diseases to shed light on our understanding of the signal characteristics of DTI.
Methods and Materials: Isoflurane, administered at 2.5% for induction and 1% for maintanence, was administered to CB57BL/6 11-week old male mice. Three normal and four diseased, at 25 days of cuprizone diet, were imaged using a 3T Siemens Allegra MR scanner. Mice were stereotactically immobilized and imaged using a custom-made volume coil. A segmented echo planar spin echo DT sequence with TR 2000 msec, TE 6.3 msec, FOV 32 mm2, and 48 averages was utilized (total acquisition time of 3 hr and 22 min). DT-MRI images were post-processed using custom written software and fractional anisotrophy was obtained.
Results: Fractional anisotrophy (FA) maps of the mice show a clear differentiation between white and gray matter. As opposed to the surrounding brain tissue with a FA of approximately 0.10 to 0.17, white matter of controls presents with high FA values ranging from 0.39 to 0.48 throughout the external capsule to 0.39 to 0.72 in the dorsal fornix region of the corpus callosum. Cuprizone mice show slightly lower FA values of 0.34 to 0.46 in the external capsule and 0.23 to 0.65 in this dorsal fornix region. Histological confirmation is pending.
Conclusion: DT-MRI has proven potentially sensitive in differentiating between partially demyelinated and fully myelinated white matter.
Brubaker, L,
The Use of Diffusion Tensor Imaging to Evaluate Demyelination Processes in Mice. Radiological Society of North America 2003 Scientific Assembly and Annual Meeting, November 30 - December 5, 2003 ,Chicago IL.
http://archive.rsna.org/2003/3107841.html
