MR spectroscopy (MRS) and spectroscopic imaging (MRSI) obtain metabolic information noninvasively from nuclei spins. For in vivo applications, common MR-active nuclei are protons (1H), phosphorus (31P), carbon (13C), sodium (23Na), and xenon (129Xe). The most common are protons due to their high gyromagnetic ratio and natural abundance in the human body. Since most metabolic processes involve carbon, 13C spectroscopy is a valuable method to measure in vivo metabolism noninvasively [1,2,3]. 13C spectra are characterized by a large spectral range (162–185 ppm), narrow line widths, and low sensitivity due to the low gyromagnetic ratio (a quarter as compared to protons) and natural abundance of 1.1% in vivo. However, the sensitivity can be increased with the use of 13C-enriched agents and by hyperpolarization.

Hyperpolarized (HP) 13C MRI is a method that magnetizes 13C probes to dramatically increase signal as compared to conventional MRI [3]. Metabolic and functional HP 13C MRI is a promising diagnostic tool for detecting disorders linked to altered metabolism such as cancer, diabetes, and heart diseases [4], increasing sensitivity sufficiently to map metabolic pathways in vivo without the use of ionizing radiation, as in positron emission tomography (PET) imaging. Metabolic imaging using HP 13C compounds has been translated successfully into single-organ examinations in healthy controls and various patient populations.

MR spectroscopy (MRS) and spectroscopic imaging (MRSI) obtain metabolic information noninvasively from nuclei spins. For in vivo applications, common MR-active nuclei are protons (1H), phosphorus (31P), carbon (13C), sodium (23Na), and xenon (129Xe). The most common are protons due to their high gyromagnetic ratio and natural abundance in the human body. Since most metabolic processes involve carbon, 13C spectroscopy is a valuable method to measure in vivo metabolism noninvasively [1,2,3]. 13C spectra are characterized by a large spectral range (162–185 ppm), narrow line widths, and low sensitivity due to the low gyromagnetic ratio (a quarter as compared to protons) and natural abundance of 1.1% in vivo. However, the sensitivity can be increased with the use of 13C-enriched agents and by hyperpolarization.

Hyperpolarized (HP) 13C MRI is a method that magnetizes 13C probes to dramatically increase signal as compared to conventional MRI [3]. Metabolic and functional HP 13C MRI is a promising diagnostic tool for detecting disorders linked to altered metabolism such as cancer, diabetes, and heart diseases [4], increasing sensitivity sufficiently to map metabolic pathways in vivo without the use of ionizing radiation, as in positron emission tomography (PET) imaging. Metabolic imaging using HP 13C compounds has been translated successfully into single-organ examinations in healthy controls and various patient populations [5,6,7,8,9,10].