C. Tanner et al, A Method for the Comparison of Biomechanical Breast Models, MMBIA01
Biomechanical models of the breast are being developed for a wide range
of applications including image alignment tasks to improve diagnosis and
therapy monitoring, imaging related studies of the biomechanical properties
of lesions,
and image guided interventions.
In this paper we present a method
to evaluate the accuracy
with which biomechanical breast models based on finite element methods
(FEM) can predict the displacements of tissue within the breast.
Our experimental data was obtained by compressing the breast of a
volunteer in a controlled manner, and the acquisition of MR images
of the breast before and after compression. Non-rigid registration of these
two MR volumes together with interactive identification of corresponding
landmarks
provided an independent estimate of the displacements. In
addition, the non-rigid registration provided estimates of the displacements
of the surface points (skin points) of the breast.
The accuracy of the FEM models was evaluated using all or a subset of these
surface
displacements as boundary conditions.
The influence of pectoral muscle movement
on the performance of the FEM models was also investigated.
Our initial results indicate that the accurate setting of the
boundary conditions is more important than the actual choice of elastic
properties in these compression scenarios. With the complete boundary
conditions, the displacements
agreed to within 2.6mm for all FEM models on average.
Assuming no movement at the posterior or the medial side of the breast,
the accuracy of the FEM models deteriorated to worse than 4.6mm
for all models.
Last modified: Tue Jan 29 17:15:50 GMT 2002