Tricia PangNovember 25, 2008
Three-Dimensional Human Airway Segmentation for Sleep Apnea Diagnosis
using Tubular Deformable Organisms
Motivation Approach
Preliminary Investigation Deformable Organisms
Preliminary Results Conclusion
OVERVIEW
Motivation Approach
Preliminary Investigation Deformable Organisms
Preliminary Results Conclusion
OVERVIEW
Motivation Obstructed sleep apnea
(OSA) disorder Caused by collapse of soft
tissue walls in the airway → model patient's airway to help diagnosis
Hand-segmentation: laborious
Goal: to develop automated tool for creating a patient-specific model of the airway
Credit: Wikipedia
Motivation Artisynth [2] &
OPAL Project(OPAL = Dynamic Modeling of the Oral, Pharyngeal and Laryngeal Complex for Biomedical Engineering) Import resulting
airway into dynamic throat and mouth model for simulation
Motivation Approach
Preliminary Investigation Deformable Organisms
Preliminary Results Conclusion
OVERVIEW
Data Source - MRI
Normal subjects, OSA patients, various treatments Volumetric and cross-sectional measurements
Motivation Approach
Preliminary Investigation Deformable Organisms
Preliminary Results Conclusion
OVERVIEW
Preliminary Investigation
Combined 2D segmentation of axial slices in Matlab Procedure:
User-indicated start point at base of airway Starting on axial slice at start point, grow ellipse outward Iterate on all axial slices moving upwards along airway,
and use previous segmentation as starting contour “Active contours without edges” (Chan-Vese) [1]:
Based on Mumford-Shah framework Evolve curve by minimizing energy from image
(interior/exterior mean) and curvature
Motivation Approach
Preliminary Investigation Deformable Organisms
Preliminary Results Conclusion
OVERVIEW
Deformable Organism
I-DO: framework for ITK (McIntosh & Hamarneh) [4] Geometrical and physical layers of classical deformable
models (data-driven) Behavioral and cognitive layers for intelligent deformation
control (knowledge-driven) Related work:
Spinal crawler [5] Vessel crawler [6]
Deformable Organism
Goal: automatically segment airway by growing a tubular organism, guided by image data and a priori anatomical knowledge
Advantages: Increased accuracy Analysis and labeling capabilities Ability to incorporate shape-based
prior knowledge Modular framework
Deformable Organism Framework
Deformable Organism Framework
Deformable Organism Framework
Deformable Organism Framework
Deformable Organism Framework
Deformable Organism Framework
Deformable Organism Framework
Summary of LayersControl Center
Grow, terminate, (branch)
BehaviorGrow, fit, (branch)
Physics/DeformationSpring-mass system
Medial and boundary nodesRadial, circumferential and sheer springs
GeometricMedial-based shape representation
Tubular with symmetric cross-section (often elliptical)
Sensors‘GrowSense’
‘HessianSense’(‘BranchSense’)
Viewer Adaptor
Graphical interface for viewing geometry of DOs and their deformations in real time
Motivation Approach
Preliminary Investigation Deformable Organisms
Preliminary Results Conclusion
OVERVIEW
Motivation Approach
Preliminary Investigation Deformable Organisms
Preliminary Results Conclusion
OVERVIEW
Summary
Model of a patient’s airway valuable to diagnosing the OSA disorder
Tubular deformable organisms spring-mass system initiated at a user-indicated point grown along the airway boundary using a priori
knowledge of upper airway anatomy
References[1] Chan, T. and Vese L. Active Contours Without Edges. IEEE Transactions
on Image Processing, 10 (2001)[2] Fels, S., et al. Artisynth: A biomechanical simulation platform for the
vocal tract and upper airway. International Seminar on Speech Production (2006)
[3] Hamarneh, G. and McIntosh, C. Physics-Based Deformable Organisms for Medical Image Analysis. Proc of SPIE 5747 (2005) 326-335
[4] McIntosh, C. and Hamarneh, G. I-DO: A “Deformable Organisms” framework for ITK. Medical Image Analysis Lab, SFU. Release 0.50.
[5] McIntosh, C. and Hamarneh, G. Spinal Crawlers: Deformable Organisms for Spinal Cord Segmentation and Analysis. MICCAI (2006) 808–815
[6] McIntosh, C. and Hamarneh, G. Vessel Crawlers: 3D Physically-based Deformable Organisms for Vasculature Segmentation and Analysis. Proceedings of IEEE CVPR (2006)
Thank you!
Questions?