Automated Online EPI Distortion Correction for fMRI Applications

Geometric distortions are a well-recognised problem in echo-planar imaging (EPI), the technique most commonly used for functional imaging. This limits the accuracy of the registration between the reconstructed functional maps and high-resolution anatomical images, thus complicating the results interpretation. Increased availability of high-field imagers, where distortions are more pronounced, and high-performance gradient systems, which afford EPI with higher spatial resolution, requires the development of robust operator-independent correction techniques. Presented here is a simple and efficient fully-automated distortion correction protocol, which is based on the point-spread function mapping technique. Application of the distortion correction to a functional experiment is demonstrated