Helmet RF Applicator Enhances Thermal Magnetic Resonance Theranostics of Brain Tumours

Motivation: Thermal MR adds an interventional dimension to an MRI device. Ultrahigh-field MRI is an excellent fit for ThermalMR since it benefits from multi-channel transmission in the short wavelength regimeGoal(s): This work investigates the MRI and RF heating performance gain of a multi-channel Tx in a helmet array versus an annular array. Approach: We aim to enhance B1+ uniformity for brain MRI at 7.0T and enhance SAR10g for brain thermal therapy using perpendicular RF elements. Results: Our simulations and phantom experiments demonstrate superior mean B1+ coverage and better B1+ uniformity for MRI and enhanced SAR10g for thermal therapy using the helmet configuration. Impact: Dome-shaped helmet transmit RF applicators provide a viable alternative for theranostics involving ultrahigh-field MRI and targeted RF-heating for thermal therapy The performance gain of the helmet transmit RF applicator is demonstrated in numerical simulations and in experiments at 7.0 T.