Figure 3.

Results of 2-dimensional parallel excitation pulse design: (A) residuals of each conjugate-gradient step in the proposed method; and (B) relative difference to the residuals with the conventional method (with matrix-vector multiplications and conjugate gradient); (C) Excited patterns using pulses designed by (left) the conventional method and (right) the proposed method. Note that the two methods achieved the same accuracy in term of NRMSE, but the proposed method is eight times faster.