Figure 1. Demonstration of VCC-ssEPI compared to conventional ssEPI. With an 8Tx array and an 8.7ms 3-spoke pTx pulse, the VCC-ssEPI jointly achieved a relatively homogeneous flip angle distribution and the target VCC phase optimized by the 32Rx array, showed no obvious SNR degradation due to flip angle homogeneity, and achieved same SENSE g-factor with x6 acceleration as the conventional ssEPI with x3 acceleration.

Figure 2. Demonstration of VCC-msEPI compared to shuttered msEPI, showing the ideal excitation patterns, achievable excitation patterns from pTx pulse design, and the 1/g factor map from different excitation strategies. Off-target excitation between the bands cannot be minimized with limited pulse duration and RF power limit, and the shuttered msEPI showed degraded 1/g map and thus reduced SNR compared to VCC msEPI.