Spectral-spatial excitation for rapid imaging of DNP compounds.

Dynamic nuclear polarization and dissolution offer the exciting possibility of imaging biochemical reactions in vivo, including some of the key enzymatic reactions involved in cellular metabolism. The development of new pulse sequence strategies has been motivated by demanding applications, such as the imaging of hyperpolarized metabolite distributions in the heart. In this article, the key considerations surrounding the application of spectral-spatial imaging pulse sequences for hyperpolarized (13)C metabolic imaging in cardiac and cancer applications are explored. Spiral pulse sequences for multislice imaging of [1-(13)C]pyruvate in the heart were developed, as well as time-resolved, three-dimensional, echo-planar imaging sequences for the imaging of [1-(13)C]pyruvate-lactate exchange in cancer. The advantages and challenges associated with these sequences were determined by testing in pig and rat models.