Title
Optimization of brain conformal mapping with landmarks.
Abstract
To compare and integrate brain data, data from multiple subjects are typically mapped into a canonical space. One method to do this is to conformally map cortical surfaces to the sphere. It is well known that any genus zero Riemann surface can be conformally mapped to a sphere. Therefore, conformal mapping offers a convenient method to parameterize cortical surfaces without angular distortion, generating an orthogonal grid on the cortex that locally preserves the metric. To compare cortical surfaces more effectively, it is advantageous to adjust the conformal parameterizations to match consistent anatomical features across subjects. This matching of cortical patterns improves the alignment of data across subjects, although it is more challenging to create a consistent conformal (orthogonal) parameterization of anatomy across subjects when landmarks are constrained to lie at specific locations in the spherical parameter space. Here we propose a new method, based on a new energy functional, to optimize the conformal parameterization of cortical surfaces by using landmarks. Experimental results on a dataset of 40 brain hemispheres showed that the landmark mismatch energy can be greatly reduced while effectively preserving conformality. The key advantage of this conformal parameterization approach is that any local adjustments of the mapping to match landmarks do not affect the conformality of the mapping significantly. We also examined how the parameterization changes with different weighting factors. As expected, the landmark matching error can be reduced if it is more heavily penalized, but conformality is progressively reduced.
Year
Venue
Keywords
2005
MICCAI (2)
conformal parameterization,conformal parameterizations,consistent conformal,conformal parameterization approach,brain data,cortical surface,brain conformal mapping,cortical pattern,parameterization change,conformal mapping,map cortical surface,riemann surface,conformal map,parameter space
Field
DocType
Volume
Weighting,Riemann surface,Parametrization,Pattern recognition,Computer science,Conformal map,Artificial intelligence,Parameter space,Energy functional,Landmark,Distortion
Conference
8
Issue
ISSN
ISBN
Pt 2
0302-9743
3-540-29326-4
Citations 
PageRank 
References 
18
1.01
3
Authors
4
Name
Order
Citations
PageRank
Yalin Wang1104279.53
Lok Ming Lui233230.16
Tony F. Chan38733659.77
Paul Thompson43860321.32