Visualizing Differences of DTI Fiber Models Using 2D Normalized Embeddings

Illustrating the differences between DTI fiber models is important for the purposes of group comparison, atlas construction, and uncertainty analysis. Standard approaches show difference between DTI models in 3D space, with either voxel-based or fiber based comparison. We proposes a new method that embeds a high-dimensional 3D fiber model as a continuous map in a 2D normalized space, built on fibers from all targeted fiber models. One advantage over previous 2D embedding approaches is that our method represents all fiber models in a unified coordinate system by taking a cluster-and-project routine, ensuring that closely located fibers from different models will be projected to close points on the 2D map. Using this projected 2D map, subtle differences that are difficult to distinguish in 3D space can be clearly displayed and individual fiber model can be effectively summarized. We applied our method to group comparison and analysis of various fiber models.