1. Groupwise Registration and Atlas Estimation
Anand Rangarajan
Center for Computer Vision, Graphics and Medical Imaging (CVGMI)
University of Florida

2. Brain Mapping motivation
Direct Comparison of Subjects
Distribution Before Alignment
Brain Functional Image
Alignment of Subjects
A good example to understand the need of brain registration/alignment.
Find significant links between certain structures and certain functions.
Need to look at multiple people.
Comparison of Subjects After Alignment
Distribution After Alignment

3. ICP: Iterated Closest Point
RPM: Robust Point Matching
First some representative examples.

4. Synthetic Study Setup
Change the choice of features to compare method I, II and III
Template
True Deformation (GRBF)
Target
Error Evaluation
Feature Matching
To carry this comparison objectively, synthetic experiments.
/// real data no ground truth. Hard for quantitative comparison.
Setup.
/// (Note the different transformation used).
/// Error by comparing the volume.
Choice of feature.
Estimated Deformation (TPS)
Template
Recovery

5. Results: Method I vs. Method III
Results: I vs III
/// Rich information, major ones.
/// III smaller errors.
Outer cortical surface alone can not provide adequate information for sub-cortical structures.
Combination of two features works better.

6. Results: Method II vs. Method III
Errors, II significantly big for a few structures.
Major sulcal ribbons alone are too sparse --- the brain structures that are relatively far away from the ribbons got poorly aligned.
Combination of two features works better.

7. Shape Atlas Estimation
Nine 3D hippocampal point-sets

8. Estimated atlas
Overlay of point-sets
Point-sets warped into atlas space
Affine warping

9. Atlas Estimation in 3D

10. Groupwise Image Registration
No reference image

11. Multiple Image results
VHD
Segmented
VHD
Brainweb

12. Acknowledgements Collaborators
Haili Chui (R2 Technologies)
Jim Duncan (Yale)
Stephan Eisenschenk (Neurology, UF)
Ajay Gopinath (GE Global Research)
Hongyu Guo (Texas A&M)
Sarang Joshi (UNC, Chapel Hill)
Christiana M. Leonard (Neuroscience, MBI, UF)
Adrian Peter (UF)
Arunabha Roy (GE Global Research)
Ilona Schmalfuss (Neuroradiology, UF)
Bob Schultz (Yale)
Baba Vemuri (UF)
Fei Wang (IBM)
Laurent Younes (Johns Hopkins)
Jie Zhang (Oracle)
Supported in part by NSF , NSF and NIH R01 NS046812