Locally Switching Between Cost Functions in Iterative Non-rigid
Registration

William Mullally, Margrit Betke,
Computer Science Department, Boston University

Carissa Bellardine and Kenneth Lutchen
Department of Biomedical Engineering, Boston University

In non-rigid image registration problems, it can be difficult to
construct a single cost function that adequately captures concepts of
similarity for multiple structures, for In non-rigid image
registration problems, it can be difficult to construct a single cost
function that adequately captures concepts of similarity for multiple
structures, for example when one structure changes in density while
another structure does not. We propose a method that locally switches
between cost functions at each iteration of the registration
process. This allows more specific similarity criteria to be embedded
in the registration process and prevents costs from being applied to
structures for which they are inappropriate. We tested our method by
registering chest computed tomography (CT) scans containing a healthy
lung to scans of the same lung afflicted with acute respiratory
distress syndrome (ARDS). We evaluated our method both visually and
with the use of landmarks and show improvement over existing
methodology.