A Subject-Specific Workflow for Radiofrequency Safety of Infants Undergoing an MRI Head Scan at 7T

Motivation: Higher SNR promised at higher field strengths can be traded for higher spatial resolution, which is essential for imaging infant brains. Goal(s): To assess and ensure safe operation of a commercially-available RF head coil at 7T for infant subjects. Approach: We developed an EM model of the coil and experimentally validated it. Utilizing EM simulations, we calculated local and head SARs for an infant model to determine the safe operation limits. Results: We showed that the head SAR limit is reached before the local SAR limit. We acquired structural and functional MRI data from an infant's brain at 7T. Impact: Assessing and ensuring the safe operation of 7T MRI scanners for infant subjects can pave the way to exploring the early stages of human brain development, which is hardly possible at lower field strengths due to lower spatiotemporal resolution.