Thermal Simulations in the Human Head for High Field MRI Using Parallel Transmission

Aurlien MASSIRE¹, Martijn CLOOS¹, ², Michel LUONG², Alexis AMADON¹, Alexandre VIGNAUD³, Christopher J. WIGGINS¹, Denis LE BIHAN¹, Nicolas BOULANT¹

Numerical simulations were performed to investigate the compliance of the specific absorption rate versus the temperature guidelines for the human head in MRI procedures utilizing parallel transmission at 7 T. Computations using finite elements and finite difference time domain techniques were implemented on a human head model to perform the electromagnetic and thermal simulations respectively. Temperature evolution throughout the head was calculated by integrating numerically the Pennes bioheat equation for 1000 parallel transmission scenarios corresponding to random static RF configurations, for the synthesized circularly polarized (CP) mode, and for two realistic Transmit-SENSE RF exposures.