Magnetic Resonance Imaging (MRI) represents a versatile, noninvasive diagnostic tool, but suffers from low sensitivity, due in part to the very low levels of equilibrium nuclear spin polarization. Very large (∼ 10 5 ) polarization enhancements are available by hyperpolarization techniques , leading to the possibility of imaging low-concentration metabolites, with important clinical applications . Hyperpolarization is particularly advantageous for 13 C-labelled substances, since 13 C nuclei often have relatively long relaxation times compared to the abundant protons, allowing the hyperpolarization effect to persist longer, as well as a large chemical shift range, facilitating compound-specific imaging. For example, hyperpolarization of 13 C-labelled metabolites such as pyruvate, fumarate and succinate (1,4-butanedioic acid, see figure ) allow monitoring of the tricarboxylic acid (TCA) cycle, exposing metabolic anomalies which are indicative of disorders such as cancer .