Christian Baumgartner1, Ofer Pasternak2, Sylvain Bouix2, Carl-Fredrik Westin3, Yogesh Rathi2
1Information Technology and Electrical Engineering, ETH Zrich, Zrich, Switzerland; 2Psychiatry Neuroimaging Laboratory, Harvard Medical School, Boston, MA, United States; 3Laboratory of Mathematics in Imaging, Harvard Medical School, Boston, MA, United States
In this work, we describe a tractography method that simultaneously estimates multiple diffusion tensors and an isotropic component, we term as free water. The model consists of three Gaussian tensors, one of which represents isotropic diffusion of free water, that are fitted to the DWI-signal using an unscented Kalman filtering framework. By this means, each estimation is guided by those previous, resulting in an inherent regularization of the tracts. The proposed method can be useful in tracing fibers through edema or lesions, where traditional tractography algorithms fail.
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