With this award, the Chemical Measurement and Imaging Program is supporting a collaborative team comprised of research groups in Russia (led by Igor Koptyug of ITC Novosibirsk) and the US (led by Boyd Goodson of Southern Illinois University at Carbondale and Eduard Chekmenev of Vanderbilt University) for research to improve the capabilities of nuclear magnetic resonance, or NMR, the key technology behind magnetic resonance imaging (MRI), a widely used diagnostic tool in modern medicine. The investigators are exploring a possible modification that could enhance the sensitivity of this technique by many orders of magnitude, thus improving MRI while also contributing to the improvement of technologies for visualizing other types of systems. The research is exploring the use of a special form of hydrogen known as parahydrogen that has been shown to enhance an NMR signal. The work is bringing a variety of techniques to bear on the task of understanding how this special form of hydrogen works in order to develop more accurate and sensitive imaging methods. The work is having a broad impact on the development of new scientific instruments that will find applications in a wide variety of fields from medicine to chemical manufacturing. It is having a further broad impact by bringing scientists together across borders to work on problems of mutual global interest. This project is contributing to the training of the next generation of scientists by providing opportunities for students at all levels to participate in a highly interdisciplinary, multi-site training environment. Specifically, students at the US sites are able to visit and carry out research projects at the international collaborator's site in Novosibirsk, one of Asia's most important research hubs.
The overall objective is to develop new catalytic materials and approaches that can dramatically improve the applicability of parahydrogen induced polarization (PHIP) techniques. Low detection sensitivity remains an Achilles Heel of many conventional methods such as NMR and MRI. However, the pure anti-phase spin order of parahydrogen (pH2) can be exploited to achieve highly non-equilibrium nuclear spin population distributions ("polarizations") in certain types of molecules, thereby enabling the enhancement of NMR/MRI detection sensitivity by orders of magnitude. More specifically, these efforts concern the synthesis, evaluation, and NMR demonstration of: 1) new heterogeneous catalysts for traditional PHIP (which involves the hydrogenation of unsaturated moieties with pH2); and 2) new homogeneous and heterogeneous catalysts for SABRE (signal amplification by reversible exchange - a technique where spin order is transferred from pH2 to molecules without requiring irreversible chemical change). New approaches exploiting in situ high-field SABRE are also under study. Additionally, these experiments are supported by the construction of an automated portable HET-PHIP/SABRE polarizer with in situ MR detection and automated pH2 generation. These research efforts endeavor to provide greater insight into current limitations for key PHIP approaches, while working to dramatically improve their utility.
