Whole-blade Propeller Dwi

Introduction PROPELLER [1] is a variant of multi-shot FSE technique, providing a high-resolution DWI with excellent immunity to offresonance. Its self-navigated nature around the center of K-space also allows for motion correction. The odd/even echo phase inconsistencies in the non-CPMG echo train were addressed using the “split-blade” method [2], where the blade width was reduced by a factor of two, making the motion-related phase more difficult to remove [3]. Thus, this work applied the “whole blade” method [3] to create wider blades for robustly removing the motion-induced phase. The proposed scheme added the reference blade (only for b=0) to effectively remove the coil phase of odd/even echoes. This reference blade can also be used for GRAPPA kernel training for parallel imaging to further widen the blade and reduce the scan time. Method The motion-induced phase alternates the sign between even and odd echoes in a DW FSE sequence [3]. The whole blade approach makes the motion phase consistent for even and odd echoes. The flowchart of this approach is shown in Figure 1. After the whole blade is created, the motion phase can then be removed for each blade. The remaining reconstruction is the same as for conventional PROPELLER [1].