Susceptibility artifact correction in GE images

In Gradient Echo (GE) images, susceptibility artifact induces both intravoxel dephasing and pixel shifting (Fig. 2-a) leading to intensity and geometric distortions [1] that may disturb image analysis. In previous works, correction of GE images is assessed by modifying acquisition parameters or by using specific sequences [2]. All the proposed techniques always constrain the acquisition process and a trade-off has to be found with the initial imaging goal. So far, there is no image processing existing method. In this work, we propose an original image-processing based correction method for susceptibility artifact in GE MR Images when a field map of the imaged object is known. Susceptibility artifact impact is modeled by means of a pixel shifting map and an intensity distortion map. The intensity distortion map which takes into account different complex phenomena is obtained through MRI simulation.