Lactate Spectroscopic Imaging on a portable 46 mT Halbach MRI scanner

Motivation: Magnetic resonance spectroscopy at ultralow-field (B0 < 0.1T) on portable MRI scanner is challenging due to the low signal-to-noise ratio (SNR) and the impossible spectral separability. Goal(s): To obtain spectroscopic images of lactate at different concentrations in a phantom on our 46mT Halbach point-of-care MRI scanner and maximize SNR with incorporation of composite refocusing pulses. Approach: We modified a non-localized Carr-Purcell-Meiboom-Gill (CPMG) echo train sequence to perform 2D J-spectroscopic imaging in lactate phantom with composite refocusing pulses for improved SNR. Results: We showed the first steps towards lactate spectroscopic imaging at ultralow-field. Impact: The implementation of lactate spectroscopic imaging could add value to the growing list of biomedical applications of low field MR systems, for example in neonatal hypoxic ischemic encephalopathy.