Individual voxel models for head SAR estimation

Motivation: Accurate human tissue models for simulation of RF power absorption are a key safety requirement for transmit coil development especially at ultra-high field. Goal(s): To create individual voxel models of the human head and torso. Approach: A pipeline for head and torso segmentation was developed based on a 3T multi-contrast protocol and tailored post-processing. The resulting voxel models were used for electromagnetic simulation of a self-developed Tx array at 9.4T. Results: Strong agreement was found between measured and simulated B1+ maps using the generated voxel model. Simulated worst-case SAR distributions differed significantly between individual and ‘off-the-shelf’ voxel models. Impact: We present a pipeline for the creation of individual human tissue voxel models covering head and torso, which is based on multi-contrast MR image segmentation. This meets a central need in safety-related simulations of ultra-high field RF coil arrays.