Towards Developing Device Testing Methods in Low-Field MRI: Electrical Properties in Tissue-Mimicking Media at 0.5T

Motivation: Current ASTM standards for MRI device testing are optimized for 1.5T/3T systems. These standards require adaptation for 0.5T systems due to frequency-dependent electrical properties. Goal(s): To develop and validate a modified ASTM gel formulation matching muscle properties at 0.5T. Approach: ASTM gel formulation was modified to match muscle electrical properties at 23 MHz, and its performance evaluated through electromagnetic field simulations. Results: Adding glycine to the ASTM gel formulation successfully matched the dielectric properties of muscle at 0.5T. Electromagnetic simulations with both the ASTM and modified gels indicated that the electric field is sensitive to the selected dielectric properties. Impact: This work demonstrates the importance of matching electrical properties for device testing at 0.5T MRI. The study proposes a modified ASTM gel formulation for performing accurate device safety assessments at this field strength.