Contrast Enhanced Image Registration using Kullbach-Leibler Assisted Image Matching and Patching (KLAMP)

Introduction: Contrast Enhanced MRI data consists of frames acquired before and after contrast injection with large changes in pixel intensity values between images. These changes are difficult to correctly deal with in image alignment algorithms and enhancing features may be seen to incorrectly shrink after image registration. Dispersion in the joint image histograms is the result of both contrast change and motion artefact. Minimisation of this dispersion, for instance, by maximisation of mutual information [1] may cause mis-registration of enhancing features. If there are features in the joint image histogram between pre and post enhancement images that are due to enhancement processes, then we can seek to minimise those changes by comparison with a joint image histogram containing only motion artefact dispersion. Work related to intensity alteration has been produced by [2]. The authors sought a functional multiplicative relationship between intensities in two images in order to correct for intensity biases in the MRI acquisition in order to improve segmentation techniques. These authors seek to reduce the influence of large local contrast variations on image registration.