Automatic
extraction of sulcal curves on the human cortical surfaces using
statistical shape model
1. Overview
The cortex of the human brain is a thin convoluted surface
comprised of gyri and sulci, which are folds oriented outwards and
inwards, respectively. Studying sulcal shapes has applications in
neurosurgical planning, understanding normal variability of brains
and developmental disorders or effects of aging. Also it is very
important in spatial normalization algorithms which use sulci and
gyri as features. This project focuses on statistical shape model
of cortical sulci and automated method of deforming the shape model
to find sulcal curves in target image.
2. Methods
In this project, we build a statistical shape model
of major cortical sulci , using the unit sphere as a stereotaxic
space. Sulci are projected onto the unit sphere via a near homothetic
mapping procedure. Our model captures inter-subject variability
of the shape of the sulci, and the mean curvature along the sulcal
curves as well. The statistical shape model for the sulcal curves
is intended for automatic labeling and spatial normalization of
cortical surfaces extracted from magnetic resonance images. The
sulcal model on the unit sphere is applied to find and label sulcal
curves on the spherical maps of unseen datasets using a fully automated
hierarchical deformation scheme. Sulcal curves on the outer cortex
are extracted via an inverse spherical mapping procedure.
The model (in the middle), is applied to the spherical
map of a new image (on the left), to extrect sulcal curves on it
(lower right). Finally, the sulcal curves on the original cortex
are obtained via a inverse spherical mapping process (upper right).
3. Results
The average sulcal shape (in red), and the most significant
eigen variation (in blue) obtained from 108 training samples.
Model deforms to find the sulcal curves on the cortex.
(Click to see the .avi movies. About 4.5MB each.)
Publications
1. **Xiaodong Tao**, Xiao Han, Maryam E. Rettmann,
Jerry L. Prince and Christos Davatzikos, "Statistical Study on Cortical
Sulci of Human Brains", Proc. of Information Processing in Medical
Imaging (IPMI), p.p. 475-487, Davis, CA, 2001
2. **Xiaodong Tao**, Jerry L. Prince and Christos
Davatzikos, "Using a Statistical Shape Model to Extract Sulcal Curves
on the Outer Cortex of the Human Brain", *IEEE Trans. Med. Imag.*, 21(5):513-524,
May 2002 |