1. Registration Foundations
Bring multiple image data sets into anatomical agreement

2. The Registration Problem
Tinit . Tk .
Tfinal
Provided by Lilla Zollei

3. Applications multi-modality fusion (same patient?)
time-series processing
e.g.: MS, fMRI experiments, cardiac ultrasound
warping across patients to atlas for labeling
accommodate tissue deformations in image-guided surgery
image-guided surgery of organs other than head

4. Manual Registration Not too bad with a few data sets
Re-Position one data set for visual agreement

5. Automated Medical Image Registration
Medical image data sets
Transform (move around)
Compare with objective function
score
motion
parameters
initial
value
Optimization algorithm
Provided by Lilla Zollei

6. Estimate Relationship Among two Signals
U : a signal
V : another signal, transformed by 

7. Estimate Relationship Among two Signals
If p(U,V) is Gaussian
Then best f is correlation (or squared difference)

8. Estimate Relationship Among two Signals
If p(U,V) is UNKNOWN
Look for strongest statistical relationship among the signals
I : Mutual Information

9. Mutual Information (MI)
H : entropy
measures information content
I : Mutual Information - a statistic that measures lack of statistical independence
H(u), H(v) constant, then equivalent to minimizing joint
Entropy, which solves some problems

10. MI Registration
Default Method for Multi-Modal Medical Image Registration
Viola Wells et al. circa 96
Collignon, and Hill & Hawkes
Pluim et al. Survey, 2003: More than 160 published applications
More than 500 citations…

11. Example MRT Rigid Registration
Pre-operative SPGR MRI
Intra-operative T2-weighted MRI
Provided by D. Gering

12. Example MRT Rigid Registration
Before Registration
After Registration
Provided by D. Gering

13. Real 3D CT data

14. 3D MR data

15. “Real” CT-MR registration:
3D starting position

16. CT-MR registration final result

17. The end.
You will notice that a lot of the early work on slicer was done by graduate students
How many grad students in the audience
Computer science?
Program
Design algorithms
Postdocs?
I’m glad you people are here…
I feel that academic research is very important for society
find new algorithms for solving problems, etc
As we move towards more and more automation in
Image processing, the need for powerful, robust algorithms
For things like segmentation and registration
Is really growing
good for health care
good for commerce

18. 3D Slicer Design Cross-platform Built on VTK Open GL Easily extended
Open source platform for visualization
GE, industrial strength
C++, Tck/TK GUI
Open GL
Library interface to graphics hardware
Easily extended
Open source
Available free:

19. EM-Segmentation E-Step Compute tissue posteriors
using current intensity
correction.
Estimate intensity correction
using residuals based on
current posteriors.
In the E-Step, ….
M-Step
Provided by T Kapur

20. EM Segmentation…
Seg Result
w/o EM
Seg Result
With EM
PD, T2 Data

21. EM Segmentation: MS ExamplePD T2
Data provided by Charles Guttmann

22. EM Segmentation: MS Example
Seg w/o EM
Seg with EM