Dynamic hyperpolarized carbon-13 MR metabolic imaging of nonhuman primate brain

Abstract

Purpose To investigate hyperpolarized 13C metabolic imaging methods in the primate brain that can be translated into future clinical trials for patients with brain cancer. Methods 13C coils and pulse sequences designed for use in humans were tested in phantoms. Dynamic 13C data were obtained from a healthy cynomolgus monkey brain using the optimized 13C coils and pulse sequences. The metabolite kinetics were estimated from two-dimensional localized 13C dynamic imaging data from the nonhuman primate brain. Results Pyruvate 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. Conclusion The feasibility of using hyperpolarized [1-13C]-pyruvate for assessing in vivo metabolism in a healthy nonhuman primate brain was demonstrated using a hyperpolarized 13C 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. © 2013 Wiley Periodicals, Inc.