A Point-Wise Quantification of Asymmetry Using Deformation Fields. Application to the Study of the Crouzon Mouse Model



AbstractThis paper introduces a novel approach to quantify asymmetry in
each point of a surface. The measure is based on analysing
displacement vectors resulting from nonrigid image registration. A
symmetric atlas, generated from control subjects is registered to
a given subject image. A comparison of the resulting displacement
vectors on the left and right side of the symmetry plane, gives a
point-wise measure of asymmetry. The asymmetry measure was applied
to the study of Crouzon syndrome using Micro CT scans of
genetically modified mice. Crouzon syndrome is characterised by
the premature fusion of cranial sutures, which gives rise to a
highly asymmetric growth. Quantification and localisation of this
asymmetry is of high value with respect to surgery planning and
treatment evaluation. Using the proposed method, asymmetry was
calculated in each point of the surface of Crouzon mice and
wild-type mice (controls). Asymmetry appeared in similar regions
for the two groups but the Crouzon mice were found significantly
more asymmetric. The localisation ability of the method was in
good agreement with ratings from a clinical expert. Validating the
quantification ability is a less trivial task due to the lack of a
gold standard. Nevertheless, a comparison with a different, but
less accurate measure of asymmetry revealed good correlation.
TypeConference paper [With referee]
ConferenceMedical Image Computing and Computer-Assisted Intervention
EditorsN. Ayache, S. Ourselin and A. Maeder
Year2007    Month October    Vol. 4792    pp. 452-459
SeriesLecture Notes In Computer Science
BibTeX data [bibtex]
IMM Group(s)Image Analysis & Computer Graphics