A Scholte wave based ultrasound elastography method for imaging superficial tissue

Abstract

Pathological changes in tissues are often related to changes in tissue mechanical properties, making elastography an important tool for medical applications. Among the existing elastography methods, ultrasound elastography is of great interest due to the inherent advantages of ultrasound imaging technology, such as low cost, portability, safety, and wide availability. However, the current ultrasound elastography methods, including shear wave elastography, can readily image deep tissue but cannot assess superficial tissue. To address this challenge, we proposed an ultrasonic Scholte-wave-based approach for imaging the elasticity of superficial tissue. The feasibility of the proposed technique was tested using a gelatin phantom with a cylindrical inclusion. In the tests, Scholte (surface) and shear (bulk) waves were simultaneously generated by the same excitation but propagated in the superficial and deeper regions of the phantom, respectively. In this study, we first demonstrated that the elasticity of superficial tissue could be evaluated by utilizing the generated Scholte wave alone and further showed that a comprehensive elasticity imaging of the tissue extending from the superficial to deep regions can be achieved by combining the proposed Scholte wave technique and the conventional shear wave technique.