Why apparent contrast in elasticity of biological tissues is noticeably different for compression ultrasound elastography and OCE

The aim of this study is to compare the results of tissue stiffness estimates given by compression (strain) ultrasound elastography (S-USE) and compression optical coherence elastography (C-OCE) beyond the difference in resolution and penetration depth. Namely, the focus of this work is on the contribution of elastic nonlinearity and mechanical inhomogeneity of the tissues to the stiffness estimates and resultant diagnostic performance of these techniques. We demonstrate that in comparison with S-USE despite basically the same compression principle, the applied realization of quantitative C-OCE have novel capabilities due to its ability to obtain spatially-resolved local pressure control and the local stress-strain curve mapping within the tissue.