Accelerated chemical shift imaging of hyperpolarized ¹³C metabolites

Purpose: Chemical shift imaging (CSI) has long been considered the gold standard method for in vivo hyperpolarized ¹³C metabolite imaging because of its high sensitivity. However, CSI requires a large number of excitations so it is desirable to reduce the number of RF excitations and the total acquisition time. Methods: Centric phase encoding and three-dimensional compressed sensing methods were adopted into a CSI acquisition to improve efficiency and reduce the number of excitations required for imaging hyperpolarized metabolites. The new method was implemented on a GE MR750W scanner for routine real time metabolic imaging experiments. Results: Imaging results from phantoms and in vivo animals using hyperpolarized ¹³C tracers demonstrate that when the entire CSI dataset is treated as a single object, compressed sensing can be satisfactorily applied to spectroscopic CSI. Centric k-space trajectory data collection also greatly improves the acquisition efficiency. This combination of compressed sensing CSI and acquisition time reduction was used to perform a hyperpolarized ¹³C dynamic study. Conclusion: Compressed sensing can be satisfactorily applied to conventional CSI in hyperpolarized ¹³C metabolite MR imaging to reduce the number of RF excitations and accelerate the imaging speed to take advantage of conventional CSI in providing high sensitivity and a large spectral bandwidth. Magn Reson Med 76:1033–1038, 2016.