Fiber Renderer: A System for Visualizing Queries of DT-MRI tracts

1. Fiber Renderer:A System for Visualizing Queries of DT-MRI tracts Joshua New Dr. Jian Huang Dr. Zhaohua Ding

2. Introduction • Data and Design Decisions • View Options

3. Design Decisions • Data • Dr. Ding’s Vanderbilt group • Matlab tensor data • Mat2dat Matlab script • Dat2binf executable • IntVisWS1.2f – extracts fibers • FeatureExtractor1.4 – extracts features from DT and fiber geometry • FiberRenderer – allows querying of data

4. Design Decisions • Interactivity • Use specialized binary-tree-like data structure to allow ultra-fast querying • Leverage GPU as an extra computational resource • Allow several levels, modes, and techniques for defining queries

5. View Options

6. View Options • SeeGraph Key Commands • F1-F12 – different query/view options • Insert,Home/End,PgUp/Dn block – parameter space options • Keys – query changes • Mouse – Right-click Menu; Left-Click Interact • Display information • Current query • Current dataset elements which satisfy the query • Parameter space

7. View Options • Mouse Interaction • Right-clicking brings up intuitive menu options • Color-scheme (hot/cold, full-color, black/white) • Toggle color-by feature or cluster • Color datasets by a specific feature • Left-Clicking • Dragging in left panel rotates the grid of datasets • Dragging in right panel selects vertices

8. View Options • Three levels of query: • Vertex-level [9 features – (TurtleGeometry)Wh,Wl,Wu, (Geometry)Curv,Kappa,Torsion, (DTInfo)Planar,Spherical,Fractional Anisotropy] • Fiber-level (fiber mean for each feature) • Cluster-level (fiber length) • Key Options (query manipulation) • Each column of letters manipulate that feature • Top row letters go up, bottom row letters go down, middle row letters toggle manipulation of floor/ceiling

9. View Options • View FullScreen (F1) • Maximum detail • Cluster Query (F4-F8) • F4 toggles activeCluster – when on, clustering is performed any time the fiber query changes (clustering ~7secs with ~5K fibers) • F5/F6 – lowers/raises the floor • F7/F8 – lowers/raises the ceiling • Vertex/Fiber Query (F9) • Toggles key-control for the two query levels

10. View Options • Parameter Space Options • PageUp/Down – Raises/lowers the Y-axis feature • Home/End – Raises/lowers the X-axis feature • Insert – removes all vertices from view • Show/Hide parameter space (F12) – can be used to speed up rendering time after parametric brushing is finished • Mouse: click-and-drag brushing to select vertices, shift-click/drag to deselect vertices

11. Function Keys Keyboard F1 – Full-Screen Mode F4 – activeCluster Mode F5 – Cluster query: floor down F6 – Cluster query: floor up F7 – Cluster query: ceiling down F8 – Cluster query: ceiling up F9 – Toggle Vertex/Fiber Query Keys F12 – Show/hide parametric space Esc – Exit Parametric Interaction: Insert – deselect all parametric points Shift – deselect parametric points Home/End – X-axis up/down PageUp/Dn – Y-axis up/down Query keys: Q* – Increase floorA* for feature 0 Z* – Decrease floorA* for feature 0 A* – Toggle floor/ceiling for feature0 * Move to the right for each consecutive feature FiberRender v4.4 Reference