Definition

A hyperpolarized (HP) bicarbonate labeled with carbon C 13 (13C), with potential usage in the diagnostic nuclear magnetic resonance (NMR) imaging of cancer cells. Upon administration, carbon C 13 hyperpolarized bicarbonate can be used for the in vivo pH mapping of tumors. As tumor microenvironment (TME) are often acidic, the acidic extracellular pH can be detected and visualized upon NMR using 13C HP bicarbonate. Hyperpolarization of 13C-bicarbonate enhances NMR signals. The acidity of the TME is correlated in tumor aggressiveness, metastatic potential, and therapeutic response.