Simultaneous multi-slice imaging can accelerate image
acquisition for commonly used diffusion and functional MRI sequences. The
design of multiband pulses can be problematic due to their high peak amplitude.
Another issue is that the necessary rapid phase and amplitude modulation can be
problematic for some current MRI RF systems to reproduce. Phase related issues
can be avoided by designing purely amplitude modulated waveforms. We describe
how three current multiband pulse design techniques (phase optimisation, time
shifting and root-flipping) can be modified to produce purely amplitude modulated
pulses and find that the relative peak increase is only about 20-25%.
