The SNR maps of SENSE reconstruction for 4-channel DM array. The top row demonstrates the SNR maps with SNRrSoS as SNRfull corresponding to reduction factor R =1, 2, 4. The bottom row demonstrates the SNR maps with SNRCov-rSoS as SNRfull corresponding to reduction factor R =1, 2, 4. SNR, signal-to-noise ratio; SENSE, sensitivity encoding; DM, differential-mode.