Simon Hu1, Peder E. Larson1, Mark VanCriekinge1, Andrew M. Leach2, Ilwoo Park1, Peter J. Shin1, Galen Reed1, Hikari Yoshihara1, Robert A. Bok1, Sarah J. Nel
1Radiology and Biomedical Imaging, University of California, San Francisco, CA, United States; 2Global Research Center, General Electric, Niskayuna, NY, United States
Development of hyperpolarized technology utilizing dynamic nuclear polarization has enabled the measurement of 13C metabolism in vivo at very high SNR. Traditionally, consecutive injections of a hyperpolarized compound in an animal have been separated temporally by approximately 1 hour, with the practical minimum time between injections determined by the sample build-up time. The effects of greatly reducing the time separation between injections have not been investigated. In this study, using the new GE SpinLab DNP polarizer with the capability of simultaneously polarizing up to 4 samples, we performed dynamic and 3D echo-planar spectroscopic imaging of [1-13C]pyruvate in normal rats. For each rat, three hyperpolarized scans were performed 5 minutes apart. The results demonstrate the feasibility of detecting the uptake and metabolic conversion of HP-pyruvate within sequential acquisitions with repeat injections with a temporal resolution of 5 minutes. In normal rats this method shows minimal changes, indicating the potential for rapid monitoring of the metabolic effects of treatments and/or physiologic interventions on this time scale.