Comparison between Dielectric Resonators and a High-Permittivity Helmet to Improve the Transmit Efficiency in the Brain

In Magnetic Resonance Imaging, it is becoming common to use High-Permittivity Materials to enhance SNR and transmit efficiency. In this work we are going to compare the efficacy of two different solutions to enhance transmit efficiency, one based on an HPM helmet, and another based on dielectric resonators. These solutions have been tested when 4 dipoles are used to generate the fields. Our simulations show an increase of the transmit efficiency in the center of the brain of 23.8 % when the HPM helmet is used, while no improvement was observed for the dielectric resonators.