Techniques for Brain Morphometry
by Alain Colchester and Gérard Subsol
BIOMORPH is a European Community project that began in May 1996. Its
aim is to develop improved techniques for measurement of the size and shape
of biological structures (morphometry). Morphometry has become increasingly
important since the advent of non-invasive magnetic resonance imaging (MRI)
which is providing large volumes of data from normal as well as abnormal
individuals and allows time changes to be studied.
The techniques to be developed are generic, but the project is focused
on schizophrenia and multiple sclerosis, applications in neurology and
psychiatry where the need for improved morpho-metric techniques is particularly
clear. These are common diseases of great social and medical as well as
economic importance. In schizophrenia, changes in the morphology of various
brain structures are thought to provide important clues to the most fundamental
brain abnormalities that underlie the condition, but the changes are barely
detectable with current techniques and more research is needed to confirm
and extend existing data. In multiple sclerosis, quantification of changes
in lesions has become of great importance in serial MRI studies of how
the abnormalities relate to clinical events and for pharmaceutical trials
where improved morphometry could reduce the cost of developing new drugs.
The basic requirements for improved morphometry are similar in the different
applications. Measurement of size is hampered by the difficulties of detecting
and localising the boundaries of structures in images (segmentation), particularly
in three dimensions. Time-series analysis is limited by the ability of
accurately finding corresponding points in scans taken at different intervals
(registration). However, recent advances in both segmentation and registration
could now strengthen morphometric studies. Experts regularly describe normal
and abnormal shape in the language of anatomy and medicine, but developing
and validating computational techniques has proved difficult. In the BIOMORPH
project, we will develop and validate improved techniques for measurement
of size, shape and changes over time of brain structures shown on MR images
in schizophrenia and multiple sclerosis. The clinical research collaborators
are active in clinical research and will be able to take immediate advantage
of technological advances that arise through the project.
During the first phase of the project MR images will be segmented interactively
by the clinical experts and simple morphometry carried out. The anatomical
objects thus formed will then be studied by the experts and traditional
(mainly linguistic) shape descriptors applied to them. Computer shape descriptors
will also be applied and will be added to the data base of objects and
their attributes. This sequence will be repeated in the second phase using
advanced computer tools developed earlier in the project. Finally, these
data will be analysed to establish the differences in size and shape measurements
within the group of experts, within normal subjects, within patients suffering
from one of the clinical disorders, and between normals and each clinical
category. The effectiveness of the computer methods will then be evaluated
by comparing them with the expert methods in their reproducibility and
their ability to segregate normal from abnormal subjects. The partners
of the project are: University of Kent, UK; Project Epidaure, INRIA, France;
SGFI-ETH, Switzerland; University of Oxford, UK; Katholieke Universiteit
Leuven, Belgium.
Please contact:
Alain Colchester - University of Kent
Tel: +44 1227 827 201
E-mail: a.colchester@ukc.ac.uk
Nicholas Ayache, Gerard Subsol, Jean-Philippe Thirion - INRIA Sophia
Antipolis
Tel: +33 4 9365 7668
E-mail: {Nicholas.Ayache,
Gerard.Subsol,Jean-Philippe.Thirion}@sophia.inria.fr
