Author Description

This dissertation, "Advanced Magnetic Resonance Spectroscopy Techniques and Applications" by Peng, Cao,, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: Magnetic resonance (MR) is a well-known non-invasive technique that provides spectra (by MR spectroscopy, MRS) and images (by magnetic resonance imaging, MRI) of the examined tissue with detailed metabolic, structural, and functional information. This doctoral work is focused on advanced methodologies and applications of MRS for probing cellular and molecular changes in vivo. A single-voxel diffusion-weighted (DW) MRS method was first developed for monitoring the size changes of intramyocellular lipid droplets in vivo. This DWMRS technique was then utilized for exploring the vascular origins of the functional blood-oxygen-level-dependent (BOLD) signal. Magnetic resonance spectroscopic imaging (MRSI) enables simultaneous MRS acquisition in multiple voxels. However, MRSI is conventionally time-consuming. Therefore, a compressed sensing (CS) method was proposed in this thesis to accelerate the acquisition speed of the in vivo MRSI. It holds the potential for promoting the realization of multiple-voxel DW-MRS experiments, though the latter is still constrained by hardware in the present. The single-voxel DW-MRS method for probing lipid diffusion was first developed and evaluated in oil and muscle phantoms. The experimental sequence was demonstrated to be sensitive to diffusion restriction and free of significant artifacts. Experiments were then performed in rat hindlimb muscles in vivo. The restricted lipid diffusion behavior was characterized by apparent