Three-dimensional multimodal brain warping using the demons algorithm and adaptive intensity corrections

This paper presents an original method for three-dimensional elastic regist ration of multimodal images. We propose to make use of a scheme that iterat es between correcting for intensity differences between images and performi ng standard monomodal registration. The care of our contribution resides in providing a method that finds the transformation that maps the intensities of one image to those of another, It makes the assumption that there are a t most two functional dependencies between the intensities of structures pr esent in the images to register, and relies on robust estimation techniques to evaluate these functions. We provide results showing successful registr ation between several imaging modalities involving segmentations, T1 magnet ic resonance (MR), T2 MR, proton density (PD) MR and computed tomography (C T), We also argue that our intensity modeling mag be more appropriate than mutual information (MI) in the contest of evaluating high-dimensional defor mations, as it puts more constraints on the parameters to be estimated and, thus, permits a better search of the parameter space.