Efficient EPI Distortion Correction using Non-Phase Encoded Reference Data

Anne-Sophie Glantenay¹, Chiel J. Den Harder¹, Johan S. Van Den Brink¹, Gwenael Herigault², Jos Koonen³

Diffusion-weighted EPI has become an indispensable tool in body MRI. However geometric distortions due to field inhomogeneities may hamper comparison of the diffusion images with T2W_TSE images. Here we implement and evaluate an efficient geometry correction method based on the non phaseencoded EPI reference acquisition used for Nyquist ghost removal. The method provides accurate and robust global geometry correction in the absence of strong, local phase offsets. It does not require additional time for calibrations, and is directly compatible with parallel imaging methods.