Sodium NMR/MRI for anisotropic systems.

Area of Science:

• Biomedical NMR and MRI
• Biophysics
• Medical Imaging

Background:

• Sodium ((23)Na) is vital for physiological processes.
• Biological tissues exhibit anisotropic ion motion due to structures like fibers and membranes.
• Sodium's high NMR sensitivity makes it suitable for biomedical research.

Purpose of the Study:

• To review NMR techniques for studying (23)Na in anisotropic biological compartments.
• To highlight the application of multiple quantum coherences for (23)Na NMR.
• To cover (23)Na studies in cartilage, tendon, intervertebral discs, red blood cells, nervous system, and muscles.

Main Methods:

• Utilizing diffusion measurements to study translational motion of sodium ions.
• Exploiting multiple quantum coherences to study anisotropic rotational motion and quadrupolar interactions.
• Applying various Nuclear Magnetic Resonance (NMR) techniques for (23)Na spectroscopy and Magnetic Resonance Imaging (MRI).

Main Results:

• Anisotropic rotational motion of sodium ions leads to non-vanishing quadrupolar interactions.
• Multiple quantum coherences are effective for studying these quadrupolar interactions.
• NMR and MRI provide insights into (23)Na dynamics within diverse biological tissues.

Conclusions:

• NMR and MRI, particularly using multiple quantum coherences, are powerful tools for investigating (23)Na dynamics in anisotropic biological environments.
• Understanding sodium ion behavior is crucial for various physiological processes and disease states.
• This review consolidates current applications of (23)Na NMR/MRI in key tissues.