Figure 3.
Per-channel waveforms of the sub-pulse (nominal flip angle 10°) designed by (a) spatial domain method assuming small tip angles (STA) and (b) optimal control method with peak RF amplitude constraints, and (c) the corresponding inversion profiles within the ROI to show the peak voltage needed to achieve adiabaticity for the 3D SPSP pulse. (d) Simulated crushed spin-echo profile of the 3D SPSP pulse on resonance with Vmax = 200 V for STA design, and (e) Vmax = 125 V for optimal control design, both assuming an ideal 90° excitation. The latter approach imposes a hard limit on the peak amplitude while enabling the pulse to be used for large-tip-angle excitation and maintaining its excitation profile.