Visualization of interpolated atrial fiber orientation using evenly-spaced streamlines

• Published in: Computers in biology and medicine 2019-08, Vol.111, p.103349-103349, Article 103349
• Main Authors: Saliani, Ariane, Tsikhanovich, Alena, Jacquemet, Vincent
• Format: Article
• Language: English
• Subjects: Algorithms; Anisotropy; Atria; Atrial fiber structure; Cardiac modeling; Catheters; Chemical industry; Fiber orientation; Flow velocity; Graphical representations; Inspection; Interpolation; Iterative methods; Literature reviews; Mathematical models; Orientation behavior; Orientation field interpolation; Propagation; Separation; Streamline integration; Tubes; Visualization
• ISSN: 0010-4825; 1879-0534
• DOI: 10.1016/j.compbiomed.2019.103349

Mathematical models of electrical propagation in the atria necessitate the specification of fiber orientation, often visualized over the epicardial and endocardial surfaces. Clear graphical representation of an orientation field over a surface remain challenging, which hinders the comparison between published models. A method for the placement of evenly-spaced streamlines over a triangulated surface is proposed. Streamlines tangent to an orientation field are integrated, starting from a set of seed points. Distribution of seed points can be either uniformly random or located in the vicinity of existing streamlines. Stopping conditions are designed to prevent streamlines from getting closer than a threshold referred to as the separation distance. At each iteration, the longest among candidate streamlines is kept. Streamlines are finally rendered on the surface as tubes. The outcome is assessed subjectively by visual inspection and objectively by measuring average streamline length and average lateral distance between streamlines. Fiber orientation fields are conveniently created by angle-based interpolation from fiber tracts manually drawn based on literature review. The zebra-like representation of evenly-spaced streamlines enables clear identification of local fiber orientation. The results show that streamline density can be controlled since the lateral distance between streamlines is guaranteed to vary between 1 and 2 times the separation distance. Average streamline length can be increased by using more seed points, which offers a trade-off between quality and speed. Evenly-spaced streamline visualization of fiber orientation facilitates the description and the comparison of fiber structure in computer models of the atria. •A method for visualizing atrial fiber orientation on a surface is proposed.•Evenly-spaced and length-maximizing streamlines are iteratively placed.•Streamline density can be controlled.•An angle interpolation approach facilitates the design of orientation fields.•A literature-based epi- and endocardial atrial fiber dataset is presented.