4K-4 Estimation of Viscoelastic Properties of Tissue using Acoustic Radiation Force

The goal of this study was to investigate the dynamic behavior of a rigid sphere in viscoelastic medium in response to the impulsive acoustic radiation force. Theoretical and numerical studies were carried out first. Then, to verify our theoretical and numerical models, the experiments were performed using rigid spheres of various diameters and densities embedded into tissue-like gel-based phantoms of varying mechanical properties. A 1.5 MHz single-element focused transducer was used to apply the desired radiation force. Another single-element focused transducer operating at 25 MHz was used to track the displacements of the sphere. The results of this study demonstrate good agreement between theoretical predictions and experimental measurements. The developed theoretical model accurately describes the displacement of the solid spheres in viscoelastic medium in response to the acoustic radiation force and thus can be used to evaluate mechanical properties of tissue