Spherical harmonic representation

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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 http//www.stat.wisc.edu/mchun
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Spherical harmonic (SPHARM) representation is a
smooth basis function expansion on unit sphere
measurement
basis function expansion
sub.1
sub.2
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SPHARM for specific degrees
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Previous brute force approach. Due to a memory
problem, SPHARM over degree 40 was not possible.
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SPHARM representation of the cortex
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Average template cortex is constructed by
averaging the SPHARM coefficients.
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SPHARM of noisy cortical thickness
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What do we do with this new technique? 1.
Hippocampus and amygdala shape analysis in
autism 2. HRF modeling on cortical surface
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SPHARM representation of hippocampus Shubing
Wang
Overfitting
degree 1
degree 5
degree 10
degree 50
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Volume rendering of manual segmentation of a
normal subject (from an old study).
Left hippocampus
Right hippocampus
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Marching cubes algorithm for manual segmentation
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Manual segmentation
Improved estimation
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Superimposition of the manual to our active
contour based result. Underestimate the manual
segmentation.