Shape based landmark matching
differeomphism between brain cortical surfaces
Project Description:
In this work, we find \emph{meaningful} parameterizations of cortical
surfaces utilizing prior anatomical information in the form of anatomical
landmarks (sulci curves) on the surfaces. Specifically, we generate close
to conformal parametrizations that also give a shape-based correspondence
between the landmark curves. We propose a variational energy that measures
the harmonic energy of the parameterization maps, and the shape dissimilarity
between mapped points on the landmark curves. The novelty is that the computed
maps are guaranteed to give a shape-based diffeomorphism between the landmark
curves. We achieve this by intrinsically modelling our search space of maps
as flows of smooth vector fields that do not flow across the landmark curves,
and by using the local surface geometry on the curves to define a shape
measure. Such parameterizations ensure consistent correspondence between
anatomical features, ensuring correct averaging and comparison of data across
subjects. The utility of our model is demonstrated in experiments on cortical
surfaces with landmarks delineated, which show that our computed maps give
a shape-based alignment of the sulcal curves without significantly impairing
conformality.
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