Hyperpolarized ultra-low field (ULF) magnetic resonance to design next generation functional contrast agents

ended

Nuclear magnetic resonance (NMR) is a powerful technique that is widely applied for chemical analysis, structural biology and for medical imaging. Despite its versatility, NMR is inherently insensitive. To overcome sensitivity challenges, hyperpolarization methods were developed that enhance NMR signals by over 10,000-fold. Hyperpolarized molecules have mainly been used in standard high-field imaging as contrast agents to directly observe metabolism. Most of the contrast agents have a traceability of up to 3 minutes until the hyperpolarized signal is depleted, limiting the scope of applications. Contrast agents that are observable for longer time periods (> 10 minutes) hence promise new opportunities to probe physiological function in vivo, exceeding the state-of-the-art. Long hyperpolarization storage is especially possible in many chemicals species at ultra-low magnetic fields (< 10 millitesla), more than 1000-fold lower than typical NMR systems. My overarching goal is to introduce a novel concept of functional contrast agents using the advantages of ultra-low field (ULF) NMR spectroscopy. I will show that these contrast agents are even of interest for cancer diagnostics. In addition to a long traceability, different structural information of molecules become available in the ULF regime that I am planning to explore to design contrast agents: Changes of electron-mediated couplings between nuclear spins of different elements can be determined with unprecedented precision in the ULF regime. I have already extensively worked on this challenge and have constructed ULF-NMR devices and analyzed how molecules change their coupling patterns under ULF conditions. In addition, I have made great progress in designing molecules that can be hyperpolarized and the polarization stored for tens of minutes. Success in this project will open a gate towards better functional magnetic resonance, both for research purposes and for affordable cancer diagnostics.