Jonathan Rizzo Polimeni1, Vijayanand Alagappan1, Thomas Witzel2, Azma Mareyam1, Lawrence Leroy Wald1,2
1A. A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA; 2Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA, USA
Highly parallel arrays of small receiver coils enable dramatic gains in both SNR and accelerated imaging performance, but at a considerable cost in system complexity. Here we present a general analog mode-mixing matrix that can compress a large array coil into a small subset of channels, while retaining most of the SNR of the array. The matrix is calculated via SVD of the whitened signal correlation matrix, and implemented with phase shifters and programmable attenuators. By combining data from a 32-element array into 8 modes the mode-mixing matrix was able to retain 70% of the full-array image SNR.