Three-Dimensional High-Resolution Diffusion Tensor Imaging and Tractography of the Developing Rabbit BrainD’Arceuil H. · Liu C. · Levitt P. · Thompson B. · Kosofsky B. · de Crespigny A.
aNeuroradiology Section and bAthinous Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Boston, Mass., cKennedy Center for Research on Human Development, Vanderbilt University, Nashville, Tenn., and dDivision of Child Neurology, Weill-Cornell Medical College/New York Presbyterian Hospital, New York, N.Y., USA
Diffusion tensor imaging (DTI) is sensitive to structural ordering in brain tissue particularly in the white matter tracts. Diffusion anisotropy changes with disease and also with neural development. We used high-resolution DTI of fixed rabbit brains to study developmental changes in regional diffusion anisotropy and white matter fiber tract development. Imaging was performed on a 4.7-tesla Bruker Biospec Avance scanner using custom-built solenoid coils and DTI was performed at various postnatal ages. Trace apparent diffusion coefficient, fractional diffusion anisotropy maps and fiber tracts were generated and compared across the ages. The brain was highly anisotropic at birth and white matter anisotropy increased with age. Regional DTI tractography of the internal capsule showed refinement in regional tract architecture with maturation. Interestingly, brains with congenital deficiencies of the callosal commissure showed selectively strikingly different fiber architecture compared to age-matched brains. There was also some evidence of subcortical to cortical fiber connectivity. DTI tractography of the anterior and posterior limbs of the internal capsule showed reproducibly coherent fiber tracts corresponding to known corticospinal and corticobulbar tract anatomy. There was some minor interanimal tract variability, but there was remarkable similarity between the tracts in all animals. Therefore, ex vivo DTI tractography is a potentially powerful tool for neuroscience investigations and may also reveal effects (such as fiber tract pruning during development) which may be important targets for in vivo human studies.
Helen E. D’Arceuil
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Received: November 21, 2006
Accepted after revision: April 26, 2007
Published online: October 26, 2007
Number of Print Pages : 14
Number of Figures : 6, Number of Tables : 1, Number of References : 66
Vol. 30, No. 4, Year 2008 (Cover Date: May 2008)
Journal Editor: Campagnoni A.T. (Los Angeles, Calif.)
ISSN: 0378–5866 (Print), eISSN: 1421–9859 (Online)
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