The Chemistry of Hyperpolarized Magnetic Resonance Probes

Dr. Suh is an assistant professor with the college of pharmacy, University of North Texas Health Science Centre. She received her Ph.D. in Biomedical Engineering from UT Southwestern. She is interested in developing 13C, 15N-labeled compound as hyperpolarized MR probe that can be used as a tracer in in vivo real time metabolism study. She has been working with Dr. Park to investigate branched-chain amino acids metabolism in glioma. Zoltan Kovacs, Ph.D., UT Southwestern specializes in the design and synthesis of novel agents for magnetic resonance imaging and radiopharmaceutical applications. One major current emphasis of Dr. Kovacs’ work is generating hyperpolarized compounds for magnetic resonance spectroscopy (MRS) and imaging (MRI) of nuclei other than 1H. Conventional MRI is not well suited for imaging nuclei other than proton because of the inherently low sensitivity of NMR. The technology of supercharging the nuclear spin of molecules, called dynamic nuclear polarization (DNP) can dramatically increase the sensitivity of MRS and MRI analysis. Dr. Kovacs is designing hyperpolarized 13C-labeled compounds that can be used as tracers to analyze the flux of molecules through metabolic pathways in healthy and diseased tissues. While 13C labeled substrates can directly enter the metabolic processes, their application is limited by rapid loss of spin polarization, called T1 relaxation, ranging from few seconds to a couple of minutes. Dr. Kovacs is developing tracer molecules based on the nonradioactive isotope 89Y and other low gamma nuclei such as 107.109Ag, which can have relaxation times of up to several minutes. Dr. Kovacs is developing various hyperpolarized 89Y-containing complexes that could be used to measure physiological parameters such as pH, temperature, and the oxidation/reduction state of molecules.

• 1. Hyperpolarized tracer design, synthesis and characterization2. Optimization of hyperpolarized NMR signals in dissolution dynamic nuclear polarization3. The chemistry of parahydrogen induced polarization (PHIP)4. Beyond 13C-pyruvate: Biomedical applications with alternate hyperpolarized probes5. Technical Considerations of MRI methods for validating DNP probes in small animals