1 / 21

Using AVID for 3D Functional Region Of Interest (ROI) Creation

Using AVID for 3D Functional Region Of Interest (ROI) Creation. Jeff Hoerle jeffh@cs.duke.edu Friday Forum November 5 th , 2004. AVID - Outline. Motivation Initial Concepts Solution and Demonstration Implementation User Study Overview Future Work. AVID - Motivation.

andra
Download Presentation

Using AVID for 3D Functional Region Of Interest (ROI) Creation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Using AVID for 3D Functional Region Of Interest (ROI) Creation Jeff Hoerle jeffh@cs.duke.edu Friday Forum November 5th, 2004

  2. AVID - Outline • Motivation • Initial Concepts • Solution and Demonstration • Implementation • User Study Overview • Future Work

  3. AVID - Motivation • Where does the data used by AVID come from? Cognitive Neuroscience • Simple Example x x x x x x x x x x x x x x x x = Functional Image Acquisition

  4. AVID - Motivation • Activation Map – contains a statistical score (e.g. t-statistic) for each voxel in the functional volume that indicates the likelihood of activation due to a specific stimuli Generating an Activation Map SPM tstatprofile Functional Volumes Event List (What and when) Activation Map

  5. AVID - Motivation • What is a region of interest (ROI)? - anysub-region in space that possesses some “interesting” feature which requires further investigation • How is an ROI specified? - for a 3D volume, it typically involves a slice-by-slice investigation and selection of voxels - problem: time-consuming

  6. AVID - Motivation • Example: Functional ROI Drawing Tool

  7. AVID - Motivation • Can we use a 3D interface and interaction scheme to improve ROI creation? • What is the best way to navigate and interact in 3D using 2D interaction devices (e.g. mouse, desktop monitors)?

  8. Step One Step Two AVID – Initial Concepts • Scheme One • Specify a bounding polygon or circle • Adjust the endplanes of the projected volume • Accept or reject volume

  9. AVID – Initial Concepts • Scheme Two • Click any point in the 3D volume • Select a point along the ray cast through the volume to serve as the midpoint for the to-be-created sphere • Use mouse to modify the diameter and placement of the sphere (and possibly shape too – make the sphere an ellipsoid)

  10. AVID – Initial Concepts • Scheme Three – use a magic wand tool to select an entire cluster (connected component) of activation

  11. AVID - Solution • AVID uses a 3D magic wand • Pros: - Takes advantage of inherent clustering in activation maps - Very simple, avoid multi-step process • Cons: - What if the desired ROI consists of many small clusters of activation? - Region growth can extend beyond the desired anatomical region. What can be done to prevent this?

  12. AVID Demonstration

  13. AVID - Implementation • Windows… but why? - User population (BIAC) almost exclusively consists of Windows users • Visualization Toolkit (VTK) - Vastly sped the development of the 3D interface • Written in C++ using MFC library - VTK written in C++, making C++ an obvious choice for AVID

  14. AVID - Implementation • VTK - developed by Kitware (http://public.kitware.com/VTK) - open-source, object-oriented graphics library - written in C++ using OpenGL or Mesa as graphics API - can interface graphics API using Cocoa, Carbon, Win32 or X - has bindings written for Java, Tcl, Python

  15. AVID - Implementation Human Heart Simulation Abdomen Segmentation – SINTEF CactusX - Univ of Oslo Reservoir Model - GeoMap

  16. AVID – Implementation • VTK Pros: - design intelligently, factory classes allow the same code can be compiled for Linux, Mac, Windows (ideally) - speeds development, has pre-built visualization algorithms • VTK Cons: - VTK is HUGE and complex… over 900 classes with deep class hierarchies - doing things the “non-VTK way” can be (very) painful - not enough documentation

  17. AVID - Implementation Collaboration Diagram Inheritance Diagram

  18. AVID – User Study • Intended to be used as a feedback tool to improve functionality and extend feature set • NOT intended to provide a quality measurement of AVID based on some set of metrics • Recruit five to seven end-users to participate in a 20 – 30 minute session

  19. AVID – User Study • How does user expectation align with AVID functionality? • Do system defaults make sense? • What is the most intuitive mechanism to add/remove voxels from an ROI? - Can we think of ROI creation in terms of file selection?

  20. AVID – Future Work • Incorporate feedback from user study into new releases of AVID • Revisit the idea of 3D selection - will one of our existing schemes work? - are others out there? • Develop a “true” volumetric rendering option • Find the source of 3D rendering anomalies on VTK

  21. AVID - Acknowledgements • Rachael Brady – VTG • Allen Song – BIAC • Melanie Wright – Human Simulation Lab • Josh Bizzell – BIAC

More Related