Project Summary/Abstract. Although medical imaging has become an essential component in cancer diagnosis, many traditional technologies remain inadequate at early stages of disease onset or with localized tumors. The objective of this work is the development of hyperpolarized 13C imaging agents that effectively provide insight into the metabolic profile of tumors and thereby provide a novel clinical tool to identify malignant tissues. These chemical probes will target a hallmark of cancer metabolism known as the Warburg effect, where an increase in glycolytic activity and a decrease in oxidative phosphorylation via the tricarboxylic acid cycle are observed. Novel libraries of 13C-labeled molecular probes will be prepared in order to optimize their physical and chemical properties for clinical investigations. These agents will be employed in hyperpolarized 13C magnetic resonance spectroscopic studies using both in vitro and in vivo cancer models to identify ideal candidates for cancer imaging. These hyperpolarized 13C probes will therefore provide novel methods for cancer diagnosis and offer new opportunities for monitoring distinctive aspects of tumor metabolism, which is of broad importance to a range of scientific and biomedical communities.