Radiofrequency Antenna Helmet Array for Thermal Magnetic Resonance of Brain Tumours at 297 MHz

Thermal magnetic resonance (Thermal MR) uses an RF-applicator to add a thermal intervention dimension to a diagnostic imaging device. Optimizing the performance of RF applicator configurations can eventually improve the performance of Themal MR. Recognizing this opportunity this work examines the feasibility of multi-channel RF applicators using broadband Self-Grounded Bow-Tie (SGBT) antenna building blocks. The focus is on enhancing focal RF power deposition in a target volume by using a multi-channel helmet RF array configuration versus conventional annular RF arrays. A 10-channel helmet RF applicator was designed for Thermal MR, evaluated in EMF simulations and benchmarked against an annular RF array using the same number of RF-elements. Our phantom studies demonstrate that the helmet RF applicator affords an ~10%- 30% improvement in maximum SAR <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10g</inf> in the TV over the conventional annular RF array. Our preliminary findings obtained for the human head voxel model Duke show improved target coverage of high SAR <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10g</inf> for the helmet RF applicator.