1. Spherical harmonic representation of anatomical boundary
Moo K. Chung
Department of Statistics
Department of Biostatistics and Medical Informatics
Waisman Laboratory for Brain Imaging and Behavior
University of Wisconsin-Madison

2. Spherical harmonic (SPHARM) representation
is a smooth basis function expansion on unit sphere
measurement
basis function expansion
sub.1
sub.2

3. SPHARM for specific degrees

6. Previous brute force approach. Due to a memory problem,
SPHARM over degree 40 was not possible.

7. SPHARM representation of the cortex

8. Average template cortex is constructed by averaging
the SPHARM coefficients.

9. SPHARM of noisy cortical thickness

11. What do we do with this new technique?
1. Hippocampus and amygdala
shape analysis in autism
2. HRF modeling on cortical surface

12. SPHARM representation of hippocampus – Shubing Wang
Overfitting
degree 1
degree 5
degree 10
degree 50

13. Volume rendering of manual segmentation
of a normal subject (from an old study).
Left hippocampus
Right hippocampus

14. Marching cubes algorithm for manual segmentation

15. Manual
segmentation
Improved
estimation

16. Superimposition of the manual to
our active contour based result.
Underestimate the manual segmentation.