Anand Gopinath1, Emad Ebbini1, Lance DelaBarre2, Tommy Vaughan2
1Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN, United States; 2Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, MN, United States
In high field MRI systems, B0 of 7T and above, inhomogeneity in the RF B1+ field is mitigated by RF shimming in which multi-channel coil elements are excited with different magnitude and phases to obtain a uniform field in a region of interest (ROI). This process is termed analog beam forming. The alternative is to digitize the receive signals and perform digital beam forming: to focus on a single ROI, or multiple closely spaced ROIs, perform element pattern correction to exclude mutual coupling effects, perform nulling in a specific region and other applications. This paper provides a discussion of digital beam forming.