A maze-like metasurface design as an efficient resonator for 7T MRI

Motivation: Metamaterial-based designs have the potential to locally increase the RF field and to serve as resonators in MRI. However, many of the structure either include a high dielectric layer substrate or require large amount of lumped elements. Goal(s): Our goal was to design a metamaterial without the need for either. Approach: A novel metasurface was constructed from concentric split-rings alternatingly rotated by 90° - generating a maze-like configuration - which allowed to lower the resonant frequency. Results: The novel maze-like metasurface achieved an RF field increase in the range of x1.5-2 compared to using a surface-coil of the same dimensions. Impact: We demonstrated a new metasurface geometry that provides an efficient resonator at 298 MHz for 7T MRI. This design does not require high dielectric or lumped elements, which offers a simple implementation, a flexible setup and a high efficiency resonator.