A general framework for diffusion tensor warping

The need for warping diffusion tensor after applying a geometric transformation to an image of this modality has been previously reported. However, a careful justification of this requirement has not been provided. In this paper, on the basis of the image acquisition procedure, the effects of geometric transformations in both diffusion weighted images and in the diffusion tensors computed from them are analyzed. This provides the grounds for the description of how the tensors should be warped if the image is transformed, and it supplies a general framework in which the warping strategies previously proposed in the literature can be viewed as approaches to such theoretical warping.