COMPLEX SHEAR MODULUS RECONSTRUCTION USING ULTRASOUND SHEAR-WAVE IMAGING BY

Many pathological processes in tissues are recognized by morphological changes that reflect alterations of the soft tissue mechanical properties. Ultrasound shear-wave imaging can provide quantitative information about soft tissue mechanical properties, specifically the complex shear modulus. Advancing this field has the potential to bridge molecular, cellular, and tissue biology and to influence medical diagnoses and patient treatment. This disserta-tion describes several quantitative developments in the field of ultrasound shear-wave imaging. The initial study is a time-domain method for quan-titative reconstruction of the complex shear modulus, estimated from the tracked displacement of the embedded spherical scatterer. This study also established a methodology for independent experimental verification of esti-mated material properties using rheometer measurements. The second study presents a technique for shear-wave imaging using a vibrating needle source for shear wave excitation. An advantage of such an approach is extende