Two-Dimensional Phase Cycled Reconstruction for Inherent Correction of EPI Nyquist Artifacts

Nan-Kuei Chen¹, Alexandru V. Avram¹, Allen W. Song¹

Here we report an inherent and 2D phase correction technique to effectively remove EPI Nyquist artifacts, without needing any reference scan. A series of images are first generated by cycling through different possible values of 2D phase errors. An image with the lowest artifact level is then identified based on the background energy level. In comparison to traditional 1D correction methods, the developed 2D phase correction method is significantly more effective, particularly for oblique-plane EPI or in the presence of cross-term eddy current. The developed method can generally be applied to single-shot and segmented EPI, with or without parallel acceleration.