Consistent intensity correction of MR images

In the last few years, there has been an increasing number of research project to study the brain. These projects nowadays involve various research centers and deal with large databases of 3D images. However, the intensity of similar anatomical tissues is often different because of the acquisition process. This is problematic since the analysis of MR images (registration, segmentation and voxel-based algorithms) may rely on the hypothesis that corresponding anatomical points have a similar luminance. In this paper, a new fully-automatic method to correct for intensity differences in MR images is presented that does not require spatial alignment. We show that the intensity correction significantly improves a nonrigid registration algorithm.