Benjamin Zahneisen1, Murat Aksoy1, Julian Maclaren1, Christian Wuerslin1, and Roland Bammer1
Simultaneous-Multi-Slab-Imaging is a promising approach for high resolution DW-EPI (<1mm) where the slice profile of a typical multi-band RF-pulse limits the spatial resolution for single-shot DW-EPI. Like every multi-band technique, slab separation during a parallel imaging reconstruction requires a combination of coil sensitivity variation and k-space encoding. The most prominent way is blipped-CAIPIRINHA where k-space encoding along the slice direction is achieved by adding small gradient blips in z-direction to the EPI readout. Here we demonstrate how multi-band RF phase modulation can be used as an alternative way to encode along the slab dimension without affecting intra-slab phase encoding. The use of phase modulated RF-pulses decouples encoding between the logical intra- and inter-slab directions that are otherwise linked because there is only one physical z-gradient axis.