Hyperpolarized Silicon Particles as In-vivo Imaging Agents

This thesis describes the development of hyperpolarized silicon particles as a new type of magnetic resonance imaging (MRI) agent. Silicon particles are inexpensive, non-toxic, biodegradable, targetable, and have unique physical properties that lead to extremely long nuclear polarization times. The 29Si nuclei are hyperpolarized by low temperature dynamic nuclear polarization using naturally occurring defects at the particle surface and directly imaged using 29Si MRI. The imaging window achievable is several orders of magnitude longer than other hyperpolarized imaging agents. The technique requires no additional imaging agent to be incorporated into the silicon, and so toxicity complications are reduced.