High resolution 3D diffusion tensor imaging for delineating neuronal architectures

3D Diffusion Tensor Imaging;Motion-Induced Phase Errors;Reduced-Field-of-View Imaging;Submillimeter Resolution;Parallel Imaging;Magnectic Susceptibility;Pons;Hippocampus

Van, Anh T.

关键词: 3D Diffusion Tensor Imaging;    Motion-Induced Phase Errors;    Reduced-Field-of-View Imaging;    Submillimeter Resolution;    Parallel Imaging;    Magnectic Susceptibility;    Pons;    Hippocampus;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/18355/Van_Anh.pdf?sequence=1&isAllowed=y

美国|英语

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

【 摘 要 】

Diffusion tensor imaging (DTI) has long been an important tool for early diagnosis and monitoring of neuronal diseases as well as for understanding the connectivity of neuronal networks. However, the intrinsic problem of DTI is the partial volume effect, which worsens when the structure of interest is complex with fine neuronal tracts. Although many techniques have been proposed to improve the resolution of DTI and hence reduce the partial volume effect, high isotropic resolution DTI remains a challenge. The key difficulties are: (a) severe reduction of signal-to-noise ratio (SNR), (b) sensitivity to numerous artifacts such as motion-induced phase error and/or magnetic susceptibility, (c) requirement of maintaining a reasonable scan time (< 30 minutes). The analysis in this dissertation shows that 3D encoding is required for high isotropic resolution because of itssuperior performance in SNR efficiency (the achieved SNR over a unit of scan time) as compared to the 2D techniques. From the SNR analysis, the dissertation proposes a 3D multislab acquisition technique for achieving 1.88 x 1.88 x 2 mm3 resolution with full brain coverage within 14.4 minutes and a 3D fast spin echo acquisition for achieving 0.8 x 0.8 x 1 mm3 resolution with reduced field of view coverage within 22 minutes. Acquisition techniques and post processing algorithms have also been developed for correcting/minimizing common artifacts in DTI including motion-induced phase error, magnetic susceptibility and eddy currents. Simulation, phantom, and invivo results are included to verify the performance of the proposed methods.