Simultaneous Multi-Slice Excitation by Parallel Transmission Using a Dual-Row PTX Head Array

Benedikt A. Poser¹, Robert James Anderson¹, Peter Serano², Azma Mareyam², Bastien Gurin², Weiran Deng¹, Lawrence L. Wald², Victor Andrew Stenger¹

Simultaneous multi-slice (SMS) acquisitions have become popular for single-shot sequences such as BOLD and DW-EPI. SMS excitations are commonly achieved with multiband pulses. We explore parallel transmission (pTX) for SMS excitation, using differently frequency-shifted pulses on subsets of transmitters that define the excited slices. Using a dual-ring pTX coil and blippedCAIPIRINHA EPI, we show factor-2 SMS with conventional single-band pulses and factor-4 SMS using dual-band pulses on each ring. For pTX coils with inherent transmit-sensitivity encoding along the slice direction, the approach can reduce required RF power (global SAR) compared to MB pulses with as many frequency bands as slices applied on all coil elements.