Dynamic Hyperpolarized Carbon-13 MR Metabolic Imaging of Nonhuman Primate Brain

Purpose To investigate hyperpolarized C-13 metabolic imaging methods in the primate brain that can be translated into future clinical trials for patients with brain cancer. Methods(13)C coils and pulse sequences designed for use in humans were tested in phantoms. Dynamic C-13 data were obtained from a healthy cynomolgus monkey brain using the optimized C-13 coils and pulse sequences. The metabolite kinetics were estimated from two-dimensional localized C-13 dynamic imaging data from the nonhuman primate brain. ResultsPyruvate and lactate signal were observed in both the brain and the surrounding tissues with the maximum signal-to-noise ratio of 218 and 29 for pyruvate and lactate, respectively. Apparent rate constants for the conversion of pyruvate to lactate and the ratio of lactate to pyruvate showed a difference between brain and surrounding tissues. ConclusionThe feasibility of using hyperpolarized [1-C-13]-pyruvate for assessing in vivo metabolism in a healthy nonhuman primate brain was demonstrated using a hyperpolarized C-13 imaging experimental setup designed for studying patients with brain tumors. The kinetics of the metabolite conversion suggests that this approach may be useful in future studies of human neuropathology. Magn Reson Med 71:19-25, 2014. (c) 2013 Wiley Periodicals, Inc.