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In vivo DTI evaluation of white matter tracts in rat spinal cord
Author(s) -
Gullapalli Jayaroop,
Krejza Jaroslaw,
Schwartz Eric D.
Publication year - 2006
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.20622
Subject(s) - white matter , spinal cord , fractional anisotropy , corticospinal tract , diffusion mri , anatomy , fasciculus , pyramidal tracts , inferior longitudinal fasciculus , biology , medicine , neuroscience , magnetic resonance imaging , radiology
Purpose To determine whether differences in specific spinal cord white matter (WM) tracts can be detected with in vivo DTI. Materials and Methods In vivo DTI was performed on six rats at the lower thoracic region using a 4.7T magnet. Axial diffusion images were obtained with diffusion gradients applied in six independent directions, with low and high b‐values equal to 0 and 692 seconds/mm 2 , respectively. Regions of interest (ROIs) were selected corresponding to the major spinal cord tracts, including the dorsal cortical spinal tract (dCST), fasciculus gracilis (FG), rubrospinal tract (RST), vestibulospinal tract (VST), and reticulospinal tract (ReST). Results ANOVA demonstrated overall differences between tracts for all of the DTI parameters, including fractional anisotropy (FA), trace diffusion (Tr), longitudinal diffusivity (EL = λ 1 ), and transverse diffusivity (ET = (λ 2 + λ 3 )/2). Similarly to previous ex vivo analyses, the spinal cord tract with the largest and most widely spaced axons (VST) had the largest EL and ET. Conclusion The principal diffusivities appear to reflect axon morphologic differences between the WM tracts that are not as well appreciated with FA and Tr. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.