Visualizing Uncertainty in HARDI Tractography Using Superquadric Streamtubes

Abstract

Standard streamtubes for the visualization of diffusion MRI data are rendered either with a circular or with anelliptic cross section whose aspect ratio indicates the relative magnitudes of the medium and minor eigenvalues.Inspired by superquadric tensor glyphs, we propose to render streamtubes with a superquadric cross section,which develops sharp edges to more clearly convey the orientation of the second and third eigenvectors where theyare uniquely defined, while maintaining a circular shape when the smaller two eigenvalues are equal. As a secondcontribution, we apply our novel superquadric streamtubes to visualize uncertainty in the tracking direction ofHARDI tractography, which we represent using a novel propagation uncertainty tensor