Sodium-23 magnetic resonance brain imaging.

Area of Science:

• Magnetic Resonance Imaging
• Biophysics
• Medical Imaging

Background:

• Sodium-23 Magnetic Resonance Imaging (23Na MR imaging) is an emerging technique for visualizing sodium distribution in tissues.
• Recent research emphasizes pulse sequences to resolve different T2 decay components of sodium.
• Interpreting compartmental sodium distribution remains challenging due to T2 decay complexities.

Purpose of the Study:

• To review recent developments in 23Na MR imaging, focusing on T2 decay components.
• To discuss the challenges in assigning T2 components to specific sodium compartments.
• To explore potential applications of 23Na MR imaging in functional studies and disease detection.

Main Methods:

• Review of recent literature on 23Na MR imaging pulse sequences and postprocessing techniques.
• Analysis of T2 decay components (fast, slow, intermediate) in sodium imaging.
• Discussion of contrast agents, such as superparamagnetic iron oxide dextran, for compartment identification.

Main Results:

• Standard 23Na MR imaging primarily depicts interstitial and plasma sodium due to limitations in imaging fast T2 decay components of intracellular sodium.
• Challenges persist in anatomically assigning T2 components, except in easily identifiable homogeneous structures.
• Superparamagnetic iron oxide dextran may enhance plasma compartment visualization.

Conclusions:

• Current 23Na MR imaging predominantly visualizes extracellular sodium spaces.
• Further research is needed to accurately image and interpret intracellular sodium compartments.
• Potential applications include monitoring functional changes in extracellular spaces and detecting brain tumors based on T2 decay characteristics.