Magnetic Resonance Imaging on Sodium Nuclei: Potential Medical Applications of 23Na MRI

Abstract

Sodium is a key element in a living organism. The increase of its concentration is an indicator of many pathological conditions. 23 Na MRI is a quantitative method that allows to determine the sodium content in tissues and organs in vivo. This method has not yet entered clinical practice widely, but it has already been used as a clinical research tool to investigate diseases such as brain tumors, breast cancer, stroke, multiple sclerosis, hypertension, diabetes, ischemic heart disease, osteoarthritis. The active development of the 23 Na MRI is promoted by the growth of available magnetic fields, the expansion of hardware capabilities, and the development of pulse sequences with ultra-short echo time.

In-cell NMR: Why and how?

“…TQF 23 Na NMR has been applied to study the intracellular sodium levels in tumors implanted in mice or rats [256,[256][257][258][259], and even to map intracellular sodium in human brain [260,261]. TQF suffers from significant signal-to-noise losses as compared to Single-Quantum 23 Na NMR, and other 23 Na MRI strategies have been developed, which we can only mention here (see [262][263][264][265]). Recent improvements in pulse sequences permitted detection of TQ and SQ signals simultaneously with improved sensitivity, and reporting of the minute-timescale evolution of intracellular 23 Na + levels in just $15 million cells [266][267][268].…”

Imaging Sodium Dendrite Growth in All‐Solid‐State Sodium Batteries Using 23Na T2‐Weighted Magnetic Resonance Imaging

“…Therefore, work in this field has focussed on the narrower linewidths of 7 Li and its distribution within the solid‐electrolyte [14] . Likewise, 23 Na MRI is considered more challenging than 7 Li, as it has a significant chemical shift, greater quadrupole moment, and lower sensitivity than 7 Li [15] . However, these larger properties can be utilised to achieve greater image contrast.…”

“…[14] Likewise, 23 Na MRI is considered more challenging than 7 Li, as it has a significant chemical shift, greater quadrupole moment, and lower sensitivity than 7 Li. [15] However, these larger properties can be utilised to achieve greater image contrast. Specifically, with a timeincremented series of MRI experiments, spin-spin (T 2 ) relaxation can be measured at each spatial element of the object and an MRI image based on relaxation rather than spin density can be produced.…”

Comprehensive Account of Sodium Imaging and Spectroscopy for Brain Research

“…The abundance of sodium ions is almost 100% in biological tissues, but a large portion of sodium signal is found to be nondetectable due to its low signal amplitude. Due to this, accurate quantitation of sodium ions becomes difficult 10,11 present in extracellular and intracellular moiety as shown in Figure 1. Sodium concentration determination related indicators, especially tissue sodium concentration (TSC), are intrinsically important in the physiological processes, such as in the regulation of nerve signal transmission, muscle action, osmoregulation, and pH regulation.…”

“…The abundance of sodium ions is almost 100% in biological tissues, but a large portion of sodium signal is found to be nondetectable due to its low signal amplitude. Due to this, accurate quantitation of sodium ions becomes difficult , Sodium ( 23 Na) MRI and MR spectroscopy (MRS) is based on the quantitation of sodium ions that are present in extracellular and intracellular moiety as shown in Figure .…”