Correcting Geometric Distortions of Echo Planar Imaging Using Demons and Reversed Phase Encoding

M. Lyksborg¹, ², H. Lundell², N. Reislev², H. R. Siebner², R. Larsen¹, T. B. Dyrby²

Correcting for geometric distortions of Echo Planar Imaging (EPI) is extremely important for anatomical fidelity. Based on the acquisition of 2 EPIs with reversed gradient polarity, we suggest using an efficient non parametric image registration method to estimate the geometric distortion field. We demonstrate the method on 5 subjects and compare it with a minimally distorted structural image. The method achieves results similar to that of the field map and point spread function method.