Improved PSF Mapping Acceleration Technique for EPI Geometric Distortion Correction at 7 Tesla

Myung-Ho In¹, Oliver Speck¹

We propose an improved acceleration of the point spread function (PSF)data acquisition which acquires PSF data for EPI distortion correction with a new reduced sampling pattern in PSF dimension. Reduction of the PSF FOV and resolution are combined to an inhomogeneous sampling pattern. Fold-over effects caused by the high FOV reduction are resolved with by additional lines in k-space center. The results show that distortions in EPI can be corrected robustly and without loss of quality. The advantages of the proposed method for the geometric distortion correction in EPI are demonstrated in human brain in vivo at 7.0 Tesla.