Abstract
PROPELLER EPI has been introduced to substantially decrease the susceptibility-related geometric distortion along phase-encoding direction in single-shot EPI, which is severer at high fields. However, artifacts due to strong field inhomogeneities may still appear in the form of image blurring. Recently, another type of PROPELLER EPI technique [2] using the short side, rather than the traditionally long side, of blades as EPI readout direction was proposed to show that the blurring effect can be dramatically reduced due to largely shortened echo spacing. Nevertheless, the results shown in [2] did not consider the k-space weighting scheme which has been used for de-blurring [1, 3] by emphasizing the contribution of data near the spin-echo where less off-resonance phase error was accumulated. In this simulation study, we demonstrated that long-axis PROPELLER (LAP) EPI and short-axis PROPELLER (SAP) EPI can benefit differently from the weighting window due to distinct sampling trajectories.