3D-multi-echo radial imaging of ²³ Na (3D-MERINA) for time-efficient multi-parameter tissue compartment mapping

Area of Science:

• Magnetic Resonance Imaging
• Biomedical Engineering
• Medical Physics

Background:

• Sodium (23Na) MRI offers unique insights into tissue composition.
• Current 23Na MRI techniques face limitations in acquisition speed and signal-to-noise ratio (SNR).
• Efficient acquisition of T2* decay information is crucial for detailed tissue analysis.

Purpose of the Study:

• To develop and validate a time-efficient 3D radial multi-echo acquisition scheme for 23Na MRI.
• To enhance SNR in 23Na images and enable accurate T2* mapping.
• To assess the potential for improved tissue compartment characterization.

Main Methods:

• A custom 3D radial multi-echo pulse sequence was implemented.
• Measurements were performed using phantoms and in vivo human brains.
• Signal-to-noise ratio (SNR) enhancement and multi-component T2* decay analysis were conducted.

Main Results:

• The proposed method achieved rapid acquisition of 38 echoes within 160 ms.
• An average brain tissue SNR enhancement of 34% was observed compared to single-echo methods.
• Distinguishable T2* decay characteristics were identified for fluid and solid media, consistent with prior research.

Conclusions:

• The developed 3D radial multi-echo sequence provides an efficient 23Na MRI method.
• It enhances SNR and provides valuable T2* decay information without increasing scan time.
• This technique holds significant potential for advanced tissue characterization and clinical applications.