Assessment of the Inter-Subject Variability of Peak Local Specific Absorption Rate for a Head Coil at 10.5T

Motivation: The safety factor, which scales SAR matrices used in real-time SAR monitoring, is commonly dominated by inter-subject variability. However, the contributions from various sources to that variability have not been fully evaluated. Goal(s): Assess the impact of different human model variations and different patient positions inside the coil, on the predicted peak local SAR for 10.5T head applications. Approach: The SAR inter-subject variability was investigated via EM simulations of two human models along with a wide variety of head positions inside an 8-channel coil at 10.5T. Results: The variability between head models was significantly more consequential than variations in a head model’s position. Impact: Simulating realistic scenarios with wide appropriate variables, to calculate SAR with a more accurate inter-subject variability on peak local SAR, has the potential to improve patient safety without compromising the scanning quality at ultrahigh field MRI.