Wireless Split Ring Resonator Metasurface Enhances Transmission Efficiency of Surface Loop Arrays at 7T

Motivation: Metasurfaces are conceptually appealing for enhancing RF coil performance due to added degrees of freedom for shaping electromagnetic fields. Goal(s): This work focuses on development and validation of a novel split ring resonator (SRR) based metasurface for improving the performance of a two-channel surface loop array at 7.0 T. Approach: Application of a magnetic field perpendicular to SRR induces electromotive force, forming an LC circuit with resonance frequency as currents circulate between the rings. This property benefits MRI transmission field enhancement. Results: Our simulations and experimental results demonstrate that wireless metasurfaces enhance transmission efficiency of a two-channel surface loop coil array at 7T. Impact: Our approach provides technical foundation for development, implementation and validation of novel metasurfaces for RF arrays customized for UHF-MRI. Our metasurface offers customizable resonance properties by adjusting unit cells, periodicity, or structure placement to enhance transmit field efficiency and uniformity.