The breast biomechanics reference state for multi-modal image analysis

Abstract

Multi-modality imaging of the breast is becoming increasingly common, and yet combining the information from the different images is difficult due to differences in the basic imaging physics, geometry, and the loading conditions under which the breast is imaged. A key step in moving between these images will be the establishment of a computable and well-understood common reference state. The reference state we use is of the breast in an unloaded configuration, devoid of gravitational and breast compression effects. In this paper we show how breast MR images can be transformed into, and then out of, this reference state to reconstruct configurations associated with other imaging orientations. Finite element models of the breasts of two volunteers were fitted to data derived from MR images of the prone gravity-loaded configurations. These personalized models were used to predict the unloaded and supine gravity-loaded configurations and compared to MR images acquired for these states. The unloaded states were predicted with surface RMS errors of 4.2 mm and 4.1 mm for the two volunteers, whilst the supine gravity-loaded states were predicted with RMS errors of 8.4 mm and 7.7 mm. We demonstrate the transformations into and out of the reference state and discuss clinical applications of these methods. © 2008 Springer-Verlag Berlin Heidelberg.