Hyperpolarized 13C metabolic imaging allows real-time in- vivo measurements of metabolic conversion. Experiments are performed by polarization of [1-13C]pyruvate with dynamic nuclear polarization and subsequent rapid dissolution, producing a hyperpolarized liquid suitable for intravenous injection. In a previous study we examined the metabolic exchange between [1-13C]pyruvate and its downstream metabolites [1-13C]alanine, [1-13C]lactate, [1-13C]pyruvate hydrate and [13C]bicarbonate in male Wistar rats by acquiring slice-selective FID signals in slices dominated by heart, liver, and kidney tissue. Using pyruvate doses of 0.1-0.4 mmol/kg (body mass), we examined the effect of transient exposure to high pyruvate blood concentrations, causing potential saturation of cellular uptake and metabolic conversion, semi- quantitatively using signal-time integrals. Further quantification of metabolite conversion can be achieved through kinetic modeling of time-domain signals. Present kinetic models, i.e. two-side integral (2SIM) or two-side differential (2SDM) [4] represent a two-side interaction between pyruvate and one specific downstream metabolite. Since pyruvate interacts dynamically and simultaneously with all of the downstream metabolites, the purpose of this work is the implentation of a multi-side, dynamic model involving all possible biochemical pathways. It was validated by comparing it to kinetic modeling obtained with two-side integral and two-side differential models.     «

Hyperpolarized 13C metabolic imaging allows real-time in- vivo measurements of metabolic conversion. Experiments are performed by polarization of [1-13C]pyruvate with dynamic nuclear polarization and subsequent rapid dissolution, producing a hyperpolarized liquid suitable for intravenous injection. In a previous study we examined the metabolic exchange between [1-13C]pyruvate and its downstream metabolites [1-13C]alanine, [1-13C]lactate, [1-13C]pyruvate hydrate and [13C]bicarbonate in male Wista...     »