Sodium ions play a central role in membrane transport and cell homeostasis. Increased sodium concentration has been observed in brain tumors as well as neurodegenerative diseases including Alzheimer’s disease, multiple sclerosis and Huntington’s disease. While 23Na MRI of the human brain was first performed over 20 years ago, the low concentration of 23Na compared to 1H and rapid T2 decay resulted in low signal to noise (SNR) and long acquisition times, limiting its diagnostic feasibility. Recent advances in MR technology including the move to higher field strengths (e.g. 9.4T) and ultra-short echo-time sequences, has rekindled interest in 23Na imaging.