Specific absorption rate monitor for in-vivo parallel transmission at 7 Tesla

When using a transmit array at high field, it is well established that high local specific absorption rate (SAR) values can occur [1]. In order to guarantee patient safety without harsh limitations to in-vivo transmit-SENSE [2] applications, subtle SAR monitoring is therefore necessary. In the recent past, a comprehensive solution involving pre-calculated B1-field-maps and local pickup-coils was demonstrated at 3 Tesla [3]. In this work, we report the implementation of a similar design at 7 Tesla, this time based on the real-time measurement of the individual power outputs of the RF amplifiers, combined with pre-calculated simulations over a variety of human head models and positions.