Self-Grounded Bow-Tie Antennas Placed Perpendicular to B0 in a Helmet RF Array Improve B1+ Uniformity for Brain MRI at 7.0T

UHF-MR uses RF arrays to shape the magnetic field generated inside the brain. For brain MRI at 7T, a helmet shaped transmit RF array could be beneficial versus conventional annular configurations. Recognizing this opportunity this work examines the feasibility of a multi-channel TX helmet RF applicator using broadband Self-Grounded Bow-Tie (bbSGBT) antenna building blocks. The focus is on enhancing B1+ uniformity and coverage for brain MRI at 7.0T. Our findings obtained for the human head voxel model Duke demonstrate improved mean B1+ coverage and increased B1+ uniformity for the helmet configuration.