Justin Yat Cheong Lau1, 2, Albert P. Chen3, Yi-Ping Gu2, Jennifer Barry2, Charles H. Cunningham1, 2
1Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada; 2Imaging Research, Sunnybrook Research Institute, Toronto, Ontario, Canada; 3GE Healthcare, Toronto, Ontario, Canada
In order to obtain concentrations of metabolites in physical units from in vivo measurements with hyperpolarized pyruvate, it is necessary to monitor the instantaneous polarization as it decays. We present an empirical model for [1,2-13C2]-pyruvate based on the correlation between the C2 upfield-to-downfield partial integral ratio and the C1 polarization in whole pig blood. Using the blood calibration data, we estimate real-time in vivo C1 polarization decay curves from whole pig heart spectroscopic measurements. Polarization estimates obtained by this method are effectively independent of signal amplitude variations due to perfusion and metabolism.