Diffusion Tensor Imaging Predicts Hyperacute Spinal Cord Injury Severity

Abstract

"Diffusion tensor imaging predicts hyperacute spinal cord injury severity." Journal of Neurotrauma.24,6. 979-990. (2007 We recently demonstrated that in vivo derived diffusion tensor imaging (DTI) parameters are sensitive and specific biomarkers for spinal cord white matter damage. In this study, non-invasive in vivo DTI was utilized to evaluate the white matter of C57BL/6 mice 3 h after mild (0.3 mm), moderate (0.6 mm), or severe (0.9 mm) contusive SCI. In the hyperacute phase, relative anisotropy maps provided excellent gray-white matter contrast in all degrees of injury. In vivo DTI-derived measurements of axial diffusion differentiated between mild, moderate, and severe contusive SCI with good histological correlation. Cross-sectional regional measurements of white matter injury severity between dorsal columns and VWM varied with increasing cord displacement in a pattern consistent with spinal cord viscoelastic properties.

Diffusion Tensor Imaging at 3 Hours after Traumatic Spinal Cord Injury Predicts Long-Term Locomotor Recovery

“…The ljj reference value for normal VLWM at T9, the standardized injury level for locomotor behavioral assessments, was established in these experiments. Mean values of 1.82 mm 2 =msec were not significantly different from measurements previously reported at the T12-T13 vertebral level, or within the cervical spinal cord, indicating that diffusion characteristics of descending long tracts do not change significantly along the spinal axis (Kim et al, 2009aLoy et al, 2007).…”

“…These studies demonstrate for the first time that the previously reported non-invasive biomarker of axonal injury, ljj (Budde et al, 2008;Kim et al, 2006Kim et al, , 2007Loy et al, 2007;Song et al, 2002Song et al, , 2003, depicted the extent of axonal damage within critical VLWM long tracts both visually and quantitatively as early as 3 h after injury. The extent of spared normal VLWM measured using ljj hyperacutely predicted long-term behavioral recovery as assessed by BMS scores after SCI.…”

“…In these experiments, all of the VLWM, including the ventral, lateral, and ventrolateral funiculi, was included in the region of interest based on previous reports in rats describing a diffuse arrangement of axons responsible for the initiation of locomotion within these regions (Loy et al, 2002a(Loy et al, , 2002b. Dorsal contusion injuries produce disproportionate axonal damage in VLWM compared to DC at severe displacements, a finding predicted by the viscoelastic properties of spinal cord (Blight and Decrescito, 1986;Loy et al, 2007). We previously reported that ljj does not normalize, but does improve significantly (approximately 20%) within regions of interest encompassing the entire VLWM during the first 7 days after severe SCI .…”

“…Due to respiratory gating, the repetition time (TR * 1.2 sec) was slightly varied among animals according to the period of individual breathing cycle (*270 msec), with fixed echo time (TE) at 38 msec. Images, three slices per breath, were obtained with diffusion-sensitizing gradients applied in six orientations: (Gx,Gy,Gz) ¼ (1,1,0), (1,0,1), (0,1,1), (-1,1,0) , represents optimal experimental conditions within the gradient performance of our system for diffusion imaging of rodent model spinal cord (Budde et al, 2008;Hasan and Narayana, 2006;Kim et al, 2006Kim et al, , 2007Loy et al, 2007;Madi et al, 2005). Eight scans were averaged per k-space line, with field of view 10Â10 mm 2 , and data matrix 128Â256 (zero filled to 256Â256).…”

Prediction of neurological recovery in spontaneous spinal epidural hematoma using apparent diffusion coefficient values

“…13 In experimental spinal cord injury using rodents, the diffusivity, parameters obtained from diffusion tensor imaging, decreased at the site injury within 6 h. Importantly, decrement of axial diffusion predicted injury severity and correlated with histological changes. 14 Recently, diffusion tensor imaging can discriminate microstructural differences between the gray and white matter of the spinal cord with 9.4T magnet. 15 It would be intriguing if MRI parameters could discriminate different histological changes in the gray and white matter in human studies.…”