Fast multiecho balanced SSFP metabolite mapping of 1H and hyperpolarized 13C compounds

To investigate the feasibility of multiecho balanced steady-state free precession (bSSFP)-based fast chemical shift mapping hyperpolarized C-13 metabolites. The overall goal was to reduce total imaging time and to increase spatial resolution compared to common chemical shift imaging (CSI). A multiecho bSSFP sequence in combination with an iterative reconstruction algorithm was implemented. H-1 experiments were performed on phantoms and on a human volunteer in order to investigate the feasibility of the method on a system with metabolite maps that are known beforehand. C-13 experiments were performed in vivo on pigs, where CSI images were acquired also for comparison. Chemical shift images of three and four distinct H-1 resonance frequencies as well as chemical shift images of up to five hyperpolarized C-13 metabolites were successfully obtained. Fast metabolite mapping based on multiecho balanced SSFP in combination with an iterative reconstruction approach could successfully separate several H-1 resonances and hyperpolarized C-13 metabolites.