Magnetic Resonance Characterization of Axonal Response to Spinal Cord Injury
Abstract
Our overall goal is to characterize axonal and myelin damage in human spinal cord injury, its evolution over time, and response to therapy. Towards this end, we have developed a set of in-vivo magnetic resonance imaging methods. We have successfully implemented a refined high-resolution approach to imaging the transverse diffusion properties of human spinal cord in-vivo. This work reveals the internal architecture of the spinal cord white matter, not previously reported, and its distribution suggests that these diffusion results are driven by the diffusion barrier spacing. Kurtosis results support the complexity of the extracellular diffusion pathways as the primary determinant of these results. Prior work suggests that barrier spacing is largely a function of axon density, and indirectly related to the fiber diameter distribution. The imaging results also permit high-resolution identification of several white matter tracts, not otherwise visible in-vivo. We have also implemented in-vivo human subject spinal cord myelin imaging using an inhomogeneous magnetization transfer (ihMT) approach. Prior work with this method indicates that it is sensitive to myelin content, and not confounded by edema or diffusion barrier spacing. Thus, diffusion and ihMT methods combine to offer independent assessment of axonal architecture (diffusion) and myelin content (ihMT). As both methods have been accomplished in-vivo in human subjects, this work will lead directly to characterization of axonal response to spinal cord injury in patients.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 2012
- Accession Number
- ADA581417
Entities
People
- David B. Hackney
Organizations
- Beth Israel Deaconess Medical Center