| Early detection and diagnosis of breast cancer can result in improved long-term survival and fewer deaths through more effective and less traumatic treatment. Presently, imaging techniques used for diagnosis and detection of breast cancer are performed by deforming the breast from its original shape. The deformation employed by such imaging techniques permit improved diagnostic imaging of the breast, however, the imaging techniques do not take into account the biomechanical nature of breast tissue. This is largely due to the fact that the biomechanical behavior of breast tissue is not fully understood, and no standard in vivo or ex vivo testing of soft tissue exists. Since malignant masses tend to be stiffer than normal tissue, an understanding of the normal and pathological biomechanical nature of breast tissue may provide more accurate discrimination of breast masses (e.g., elastography). Also, an understanding of the biomechanical properties of breast tissue may be used to develop more accurate breast models. Biomechanically-based models can be used to develop computer algorithms to accurately mimic the deformation of breast tissue undergoing external forces typically generated during diagnosis procedures. Such models will better aid in surgical biopsies, breast conservation procedures, and may improve the prognosis for breast cancer patients.; The purpose of our study was to noninvasively characterize the in vivo force-deformation behavior of normal breast tissue under static compressive loads, with the aim of performing finite element computer simulations of tissue deformations. We present a new method to obtain in vivo deformation data by using magnetic resonance imaging to detect displacement. With small incremental compressions, corresponding displacement could be easily mapped between deformed (compressed) and undeformed (uncompressed) images. Material properties of breast tissue were evaluated by fitting the uniaxial compression data to various constitutive models.; The initial investigation into the mechanical behavior of normal breast tissue shows that under static compressive loading, breast tissue exhibits nonlinear properties similar to other soft tissues. The constitutive relationships most suitable for uniaxial test data of breast tissue are large-elastic deformation and incompressible models, such as Mooney-Rivlin and Blatz, with the Mooney-Rivlin model providing the best fit to varying tissue densities. |
