Biomedical Engineering Reference
In-Depth Information
Chapter 8
Inter-Subject Non-Rigid Registration:
An Overview with Classification and
the Romeo Algorithm
Pierre Hellier
1
8.1
Introduction
Registration is basically the process of estimating the spatial transformation
that matches two images. Registration is especially important when analyzing
motion and deformations of natural phenomena. Registration is a very active
field of research. Various techniques have been proposed so far, concerning
rigid and non-rigid methods.
Rigid registration is adapted in many applications except in some situations:
complex deformations such as soft tissue deformation, evolution of lesions over
time, matter appearance or dissipation and so on. Therefore, non-rigid registra-
tion methods (also called deformable registration) have been developed. This
chapter will be mostly concerned with non-rigid registration methods and more
particularly with a specific application: registration of brains of different sub-
jects.
During the last few years, the development of electronic brain atlases has
emerged by overcoming some limitations of traditional paper-based atlases [49,
62, 81, 92, 97, 139]. To do so, non-rigid intersubject registration methods have
been developed in order to account for the intersubject variability [92].
