Merideth Frey

Since its invention in 1973, magnetic resonance imaging (MRI) has become an invaluable tool for clinical medicine, fundamental biomedical research, the physical sciences, and engineering. The vast majority of all MRI studies, in medicine and beyond, detect only the signal from a single nuclear isotope, H-1, in liquid water. Extending the reach of MRI to the study of other elements, and to hard or soft solids, opens new frontiers of discovery. In practice, however, the slower motion of the nuclei in solid environments compared to H-1 in water results in much broader magnetic resonance (MR) spectra, limiting both the attainable spatial resolution and the signal-to-noise. Our lab recently discovered a novel nuclear magnetic resonance (NMR) pulse sequence while doing fundamental research related to the `spins in semiconductors’ approach to quantum computing. This sequence can greatly narrow the MR linewidth of solids, and it opens a new path to do high-resolution MRI of various nuclei in solids. In this thesis work, I use our pulse sequence to take the highest resolution MR images of P-31 in hard and soft solids using a conventional animal MRI system. We also have developed strategies to greatly enhance the imaging speed by making use of sparse MRI techniques as well as a new algorithm developed in our lab to do fast and accurate image reconstruction from sparse data. For future work, we propose ways to enhance spatial resolution and speed up imaging as well as discuss the potential applications of this work to a wider range of scientific problems.