Date of Award
Spring 2008
Document Type
Dissertation - Restricted
Degree Name
Doctor of Philosophy (PhD)
Department
Biomedical Engineering
First Advisor
Schmit, Brian D.
Second Advisor
Ropella, Kristina M.
Third Advisor
Schmainda, Kathleen M.
Abstract
Diffusion tensor magnetic resonance imaging (DTIMRI or RDTI) is a magnetic resonance imaging (MRI) technique that quantifies the diffusion of hydrogen atoms, primarily in unbound water molecules. In the central nervous system (CNS) diffusion is anisotropic, having a preferred direction of free diffusion parallel with axon orientation. Diffusion perpendicular to axons is restricted by boundaries from the axon cell membrane, myelin sheath, and internal structures including neurofilaments and microtubules. Thus, by monitoring the changes in diffusion characteristics within the spinal cord following injury we may deduce the microstructural organization and predict white matter integrity during recovery.
The primary purpose of this dissertation work was to characterize the spatiotemporal changes in diffusion characteristics following spinal cord injury (SCI) using DTI in both a rat model and human participants. This work is the first to completely characterize diffusion throughout the neurologically intact human and rat spinal cord, the first to monitor diffusion changes from the acute through chronic stages of SCI, and the first to investigate functional correlates of spinal cord DTI during recovery.