All surfaces can be classified by the conformal equivalence
relation. Conformal invariants, which are shape indices
that can be defined intrinsically on a surface, may
be used to identify which surfaces are conformally equivalent,
and they can also be used to measure surface deformation.
Here we propose to compute a conformal invariant,
or shape index, that is associated with the perimeter
of the inner concentric circle in the hyperbolic parameter
plane. With the surface Ricci flow method, we can conformally
map a multiply connected domain to a multi-hole disk
and this conformal map can preserve the values of the conformal
invariant. Our algorithm provides a stable method
to map the values of this shape index in the 2D (hyperbolic
space) parameter domain. We also applied this new shape
index for analyzing abnormalities in brain morphology in
Alzheimer’s disease (AD) and Williams syndrome (WS). After
cutting along various landmark curves on surface models
of the cereb...
Paul M. Thompson, Tony F. Chan, Xianfeng Gu, Yalin