Model-independent quantification of soft tissue viscoelasticity with dynamic optical coherence elastography

摘要

Mechanical properties of cells and tissues play an important role in governing both normal and diseased biological processes. Recent findings in mechanobiology have demonstrated that viscosity, independent of elasticity, of extracellular matrix (ECM) can alter cellular behaviors. To obtain a comprehensive understanding of the mechanical properties of viscoelastic biological tissues for biomedical applications and mechanobiology research, both the elasticity and the viscosity must be characterized. Although optical coherence elastography (OCE) has emerged as a promising tool for probing the mechanical properties of biological tissues, quantitative OCE methods have mostly been limited to elasticity reconstruction or relied on the use of a presumed mechanical model, which may or may not adequately describe the response of a given tissue type. We present the first experimental demonstration of a mechanical model-independent reconstruction of complex shear modulus from direct measurement of surface wave propagation in viscoelastic media with dynamic acoustic radiation force (ARF)-OCE. Our results suggest that elasticity imaging based on shear wave speed alone could overlook potentially significant variations in the viscoelastic properties of biological tissues.