Hyperpolarized bicarbonate 13C

Hyperpolarized bicarbonate 13C is a diagnostic imaging agent consisting of sodium bicarbonate labeled with the stable isotope carbon-13 and rendered hyperpolarized to dramatically enhance its magnetic resonance (MR) signal. It is used as a contrast agent in magnetic resonance imaging (MRI), specifically for noninvasive in vivo mapping of tissue pH, most notably in oncology for tumor characterization. The mechanism involves rapid equilibration between injected hyperpolarized H^13CO3^- and ^13CO2 within tissues; the ratio of these two species allows quantification of extracellular pH via MR spectroscopy or imaging. This technique enables real-time assessment of tumor microenvironment acidity, which is associated with cancer aggressiveness and therapeutic response. Hyperpolarization increases the MR signal by several orders of magnitude but requires specialized preparation immediately before use due to rapid decay of polarization[1][4][5][8]. The method has been developed primarily at academic centers such as the University of California, San Francisco[3], and has reached early-phase clinical trials for prostate cancer pH mapping.

Other names

carbon C 13 hyperpolarized bicarbonate