3D Dual-Polarity GRAPPA for Ghost Correction of Volumetric Echo-Planar Imaging Data

Motivation: 3D-EPI suffers from inherent sampling errors, similar to conventional 2D-EPI, which result in Nyquist ghosting and shading artifacts that arise from non-linear phase errors in the sampled data. Goal(s): To demonstrate that the Dual-Polarity GRAPPA (DPG) reconstruction method can be extended and applied effectively to 3D-EPI data. Approach: We modified the DPG kernel to extend to all three sampling directions, to better accomodate 3D-EPI data. Results: Phantom and in-vivo data demonstrate that DPG provides reconstructed images with lower levels of ghost artifacts and reduced artifacts from non-linear phase errors. This extension to DPG will enable high-fidelity reconstructions in future 3D-EPI applications. Impact: Our extension of Dual-Polarity GRAPPA to a 3D reconstruction kernel can improve image quality for 3D-EPI applications, providing higher fidelity and fewer artifacts than current conventional methods for improved imaging performance in emerging high-resolution fMRI and ultra-high-field imaging applications.