Application of diffusion weighted imaging in studying motor control and moving towards higher resolution diffusion imaging

Motor Control;Diffusion Imaging;Diffusion Tensor Imaging

Holtrop, Joseph ; Sutton ; Bradley P.

关键词: Motor Control;    Diffusion Imaging;    Diffusion Tensor Imaging;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/31981/HOLTROP_JOSEPH.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Diffusion weighted imaging (DWI) is a magnetic resonance imaging technique that is able to give valuable insight into neuronal structure in vivo. By looking at the diffusion of water molecules, information on the integrity of different fiber pathways are able to be observed. One particular application of DWI is to provide a non-invasive window into changes in fiber pathways with age, in hopes to better understand the aging process. Along with age-related declines in myelination of fiber pathways in the brain, there is generally a decline in performance on both cognitive and motor tasks. By combining motor control measures and diffusion metrics, the role of the neural structure in the performance of the aging motor system can assessed. The work presented here compares several different effectors to see if motor control declines differently and if that difference is related to myelination changes in fiber pathways specific to each effector. A decline in the myelination of age was observed and was also able to explain significant amounts of the age-related variance in motor control in particular motor control tasks for effectors.The ability to accurately measure effector specific pathways is limited by the spatial resolution of current DWI acquisitions. In order to get improve DWI to get more accurate measurements of specific fiber tracts, a technique to achieve higher image resolution diffusion weighted images is developed and implemented. The technique uses a 3D approach to increase SNR, while utilizing a relatively short TR, leading to a more efficient imaging scheme. Techniques to overcome the challenges associated with long readouts, motion induced phase errors, and image reconstruction were developed and tested. Results are given for 1 mm isotropic resolution on volunteer's brains scanned on a 3 T MRI scanner.