Single-Sided Magnet System for Quantitative MR Relaxometry and Preclinical In-Vivo Monitoring

Area of Science:

• Medical Physics
• Biophysics
• Neuroimaging

Background:

• Magnetic Resonance Imaging (MRI) is crucial for non-invasive brain diagnosis.
• Traditional MRI requires high magnetic field strength and homogeneity, limiting its portability and application.
• Developing portable MR systems is essential for broader clinical and preclinical use.

Purpose of the Study:

• To develop and evaluate a single-sided magnet system for measuring Magnetic Resonance (MR) relaxation and diffusion parameters.
• To assess the system's capability for preclinical applications, specifically monitoring brain tissue during hypoxia.
• To provide a portable alternative for acquiring clinically significant MR parameters.

Main Methods:

• A single-sided magnet system utilizing an array of optimized permanent magnets was developed.
• NMR relaxometry was employed to measure quantitative parameters like T1, T2, and apparent diffusion coefficient (ADC).
• The system was tested on benchtop samples and in an ovine model of acute global cerebral hypoxia.

Main Results:

• The system successfully measured T1, T2, and ADC on benchtop samples, yielding results consistent with literature.
• In vivo studies demonstrated a decrease in T2 during cerebral hypoxia, with recovery upon return to normoxia.
• The system operates effectively in a preclinical setting, projecting a 0.2 T field into the sample.

Conclusions:

• The developed single-sided MR system offers potential for non-invasive brain measurements.
• The system is capable of operating in preclinical environments and monitoring T2 during brain tissue hypoxia.
• This technology provides a portable method for obtaining key MR parameters without conventional imaging equipment.