1Electrical Engineering, Stanford University, Stanford, CA, United States
A novel phase-based B1 estimation method using adiabatic refocusing (BEAR) is proposed and validated experimentally at 1.5T. The method exhibits a linear relationship between phase and B1 that is insensitive to off-resonance, T1, and T2. Using this method, B1 mapping can be localized to a slice or 3D volume, with a spin-echo acquisition that is appropriate for fast projection measurements. These properties make BEAR an ideal candidate for use in robust transmitter gain calibration of nominally homogeneous volumetric RF coils.