Correction of Gradient Error Distortions in Echo-Planar Imaging
National Institute of Information and Communications Technology
We propose a simple and general approach to correcting the distortion due to RO field gradient errors (mainly those induced by eddy currents) based on the statistical properties of EPI images. The proposed method can correct the linear eddy-current-induced field gradient error along the RO direction even in high-resolution EPI (such as 128x128-pixel imaging) by online processing. We remove the influence of the PE field gradient from the estimation of the first-order phase error (RO gradient induced) of each RO line, and correct the linear distortion using the estimated RO-gradient-induced phase error.