1. Geodesic fiber tracking in white matter using activation function
- Author
-
Avinash Bansal, Jan Slovák, Lubomír Vojtíšek, Temesgen Bihonegn, and Sumit Kaushik
- Subjects
Geodesic ,Computer science ,Brain ,Health Informatics ,Conformal map ,02 engineering and technology ,Space (mathematics) ,White Matter ,Computer Science Applications ,03 medical and health sciences ,Diffusion Tensor Imaging ,0302 clinical medicine ,Metric (mathematics) ,0202 electrical engineering, electronic engineering, information engineering ,Anisotropy ,020201 artificial intelligence & image processing ,Metric tensor ,Tensor ,Algorithm ,Solving the geodesic equations ,Algorithms ,030217 neurology & neurosurgery ,Software ,Diffusion MRI - Abstract
Background and objective:The geodesic ray-tracing method has shown its effectiveness for the reconstruction of fibers in white matter structure. Based on reasonable metrics on the spaces of the diffusion tensors, it can provide multiple solutions and get robust to noise and curvatures of fibers. The choice of the metric on the spaces of diffusion tensors has a significant impact on the outcome of this method. Our objective is to suggest metrics and modifications of the algorithms leading to more satisfactory results in the construction of white matter tracts as geodesics. Methods:Starting with the DTI modality, we propose to rescale the initially chosen metric on the space of diffusion tensors to increase the geodetic cost in the isotropic regions. This change should be conformal in order to preserve the angles between crossing fibers. We also suggest to enhance the methods to be more robust to noise and to employ the fourth order tensor data in order to handle the fiber crossings properly. Results: We propose a way to choose the appropriate conformal class of metrics where the metric gets scaled according to tensor anisotropy. We use the logistic functions, which are commonly used in statistics as cumulative distribution functions. To prevent deviation of geodesics from the actual paths, we propose a hybrid ray-tracing approach. Furthermore, we suggest how to employ diagonal projections of 4th order tensors to perform fiber tracking in crossing regions. Conclusions: The algorithms based on the newly suggested methods were succesfuly implemented, their performance was tested on both synthetic and real data, and compared to some of the previously known approaches.
- Published
- 2021
- Full Text
- View/download PDF