Nicholas Kuzma , Ph.D.

Our laboratory explores recent advances in atomic and condensed-matter physics to create novel biomarkers and procedures for in-vivo molecular imaging. New ways of using magnetic resonance imaging (MRI) and spectroscopy (MRS) are being developed to produce non-invasive diagnostics for diseases such as atherosclerosis and cancer. Our research focuses on the practical applications of two nuclear spin-alignment (hyperpolarization) methods: spin-exchange optical pumping (SEOP) and dynamic nuclear polarization (DNP). These methods can be used to increase magnetic resonance signal strength of selected atoms and molecules by factors of 100,000 or more, in samples large enough to serve as diagnostic tools in medicine and biology.

Optically-pumped Xe as a chemical-shift probe of atherosclerotic plaques

Xenon is an inert gas, with high solubility in lipids (compared to that in water) and a wide range of chemical shifts of its nuclear magnetic resonance (NMR) frequency. These frequency shifts strongly depend on the local molecular environment in which the gas is dissolved. Xe nuclear spins can also be hyperpolarized (aligned) to a high degree (20-60%, compared to a thermal polarization of 0.00027% at 3 T) in large sample quantities (0.5 - 5 L of gas). Xenon, a mild anaesthetic, can easily be administered by inhalation, after which it is readily taken up by the blood stream. We take advantage of these properties to study chemical shifts of hyperpolarized xenon dissolved in atherosclerotic deposits within blood vessel walls, with the aim to show sensitivity and specificity of xenon spectra to the molecular composition of atherosclerotic plaques.

Development of dynamic nuclear polarization methods to produce biomarkers for cancer MRI

Today's Positron Emission Tomography (PET) makes it possible to observe metabolic processes in a living organism in real time, by tracking short-lived radioactive isotope labels as they are taken up by metabolically active tissues and tumors. The goal of our DNP project is to develop non-radioactive, hyperpolarized molecular labels that can be tracked in vivo by MRI. In addition to acquiring spatial and temporal localization data, it should also be possible to use magnetic resonance spectroscopy as a direct probe of metabolic reactions, with a possibility of distinguishing the products of metabolism through changes in chemical shifts and relaxation rates of the biomarker labels.