SAR Efficient Simultaneous Multislice Diffusion Weighted Imaging at 7T Using PINS RF Pulses

Markus Barth¹, ², Peter J. Koopmans¹, ², Rasim Boyacioglu¹, Jennifer Bersch¹, David G. Norris¹, ²

Simultaneous multislice (SMS) imaging is an efficient way to speed up multislice 2D acquisitions by exciting several slices simultaneously and reconstructing them via parallel imaging algorithms. Specifically, diffusion weighted imaging (DWI) profits largely when this technique is used, however, at high field strengths conventional multiband pulses lead to high SAR. We show that by using RF pulses where the power is independent of the number of slices (PINS), SAR and amplitude constraints can be resolved even for double-refocused spin-echo DWI at 7 Tesla leading to short acquisition times (< 3 minutes for 60 diffusion directions).