Novel Contrast Agents
Chekmenev group develops hyperpolarized magnetic resonance (MR). The technique of hyperpolarization enhances nuclear spin polarization by 4-6 orders of magnitude with the corresponding gains in MRI detection sensitivity. As a result, it becomes possible to image dilute compounds such as metabolites and functional contrast agents reporting on in cellular metabolism and organ function respectively. Chekmenev group employs several hyperpolarization techniques to develop or significantly improve the preparation of new hyperpolarization contrast (HP) agents. The focus of Chekmenev work is on low-cost and high-throughput hyperpolarization approaches such as parahydrogen-induced polarization (PHIP), signal amplification by reversible exchange (SABRE), and spin-exchange optical pumping (SEOP). For example, my group in collaboration with other research groups has developed new-generation SEOP hyperpolarization equipment, which has been employed in clinical trials and undergo. The produced contrast agent (hyperpolarized 129Xe) can be inhaled for functional 3D MRI scan of lung ventilation and gas diffusion on a single patient breath hold. With PHIP, we actively develop hyperpolarization of 13C-pyruvate and 13C-acetate to employ them for detecting aberrant metabolism in tumors. Moreover, with PHIP, we have recently demonstrated clinical-scale hyperpolarization of propane gas, which can be employed as a functional contrast agent for lung ventilation with sub-second 3D scan speed. With SABRE technology, we have been focusing on development of a wide range of molecular probes to report on abnormal metabolism (pH, hypoxia and others) in cancer and other diseases.