TY - GEN
T1 - Modeling dynamic responses of viscoelastic heterogeneous soft tissues to step acoustic radiation force
AU - Zhao, Xiaodong
AU - Pelegri, Assimina A.
PY - 2013
Y1 - 2013
N2 - The responses of soft tissue under acoustic radiation force excitations are used to image tissue mechanical properties for soft tissue discrimination and detection of breast tumors. The soft tissue viscoelasticy has been interrogated by step acoustic radiation force excitations. The corresponding induced timedependent creep displacement is used to reconstruct soft tissue viscoelasticity or to estimate viscosity and elasticity contrast of the inclusion to background. The acoustic radiation force is highly localized in a small excitation region; and, one degreeof- freedom and homogenous assumptions are generally made to the analysis. However, these simplifying assumptions limit the accuracy of these methods. In this paper, a finite element model was built to demonstrate the effect of the dynamic response of viscoelastic heterogeneous soft tissue to step acoustic radiation force. Factors affecting the dynamic response of soft tissue were first investigated with the homogenous model, and the corresponding estimation quality based on the one degree-offreedom model was evaluated. Then, the dynamic response of soft tissue with inclusion and different elasticity and viscocity for the tissue and the inclusion was studied. The results suggest that in order to improve the estimate of soft tissue viscoelasticity the heterogenenous nature of the tissue and its three dimensional geometry should be accounted in the model.
AB - The responses of soft tissue under acoustic radiation force excitations are used to image tissue mechanical properties for soft tissue discrimination and detection of breast tumors. The soft tissue viscoelasticy has been interrogated by step acoustic radiation force excitations. The corresponding induced timedependent creep displacement is used to reconstruct soft tissue viscoelasticity or to estimate viscosity and elasticity contrast of the inclusion to background. The acoustic radiation force is highly localized in a small excitation region; and, one degreeof- freedom and homogenous assumptions are generally made to the analysis. However, these simplifying assumptions limit the accuracy of these methods. In this paper, a finite element model was built to demonstrate the effect of the dynamic response of viscoelastic heterogeneous soft tissue to step acoustic radiation force. Factors affecting the dynamic response of soft tissue were first investigated with the homogenous model, and the corresponding estimation quality based on the one degree-offreedom model was evaluated. Then, the dynamic response of soft tissue with inclusion and different elasticity and viscocity for the tissue and the inclusion was studied. The results suggest that in order to improve the estimate of soft tissue viscoelasticity the heterogenenous nature of the tissue and its three dimensional geometry should be accounted in the model.
KW - Acoustic radiation force imaging
KW - Creep response
KW - Finite element method
KW - Heterogeneity
KW - Soft tissue
KW - Viscoelasticity
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U2 - 10.1115/IMECE2013-66109
DO - 10.1115/IMECE2013-66109
M3 - Conference contribution
AN - SCOPUS:84903459502
SN - 9780791856222
T3 - ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE)
BT - Biomedical and Biotechnology Engineering
PB - American Society of Mechanical Engineers (ASME)
T2 - ASME 2013 International Mechanical Engineering Congress and Exposition, IMECE 2013
Y2 - 15 November 2013 through 21 November 2013
ER -