A Novel Streamline-based diffusion MRI Tractography Registration Method with Probabilistic Keypoint Detection
This work addresses the challenge of analyzing group similarities and variations in brain white matter for researchers in neuroimaging, though it appears incremental as it builds on existing streamline-based approaches.
The paper tackled the problem of aligning diffusion MRI tractography datasets across subjects by proposing a novel unsupervised deep learning method that uses probabilistic keypoint detection to identify anatomical correspondences, resulting in highly effective and efficient registration performance.
Registration of diffusion MRI tractography is an essential step for analyzing group similarities and variations in the brain's white matter (WM). Streamline-based registration approaches can leverage the 3D geometric information of fiber pathways to enable spatial alignment after registration. Existing methods usually rely on the optimization of the spatial distances to identify the optimal transformation. However, such methods overlook point connectivity patterns within the streamline itself, limiting their ability to identify anatomical correspondences across tractography datasets. In this work, we propose a novel unsupervised approach using deep learning to perform streamline-based dMRI tractography registration. The overall idea is to identify corresponding keypoint pairs across subjects for spatial alignment of tractography datasets. We model tractography as point clouds to leverage the graph connectivity along streamlines. We propose a novel keypoint detection method for streamlines, framed as a probabilistic classification task to identify anatomically consistent correspondences across unstructured streamline sets. In the experiments, we compare several existing methods and show highly effective and efficient tractography registration performance.