The biomechanical properties of biological tissues are closely related to their physiological state, including inflammation and the development of disease. Since ancient times, clinicians have assessed tissue elasticity through palpation, making it one of the oldest diagnostic techniques in medicine. Although palpation remains a valuable clinical screening tool for detecting superficial abnormalities, the advent of medical imaging has transformed tissue elasticity assessment into a noninvasive modality capable of visualizing and quantifying tissue mechanical properties. Ultrasound elastography, in particular, combines the advantages of conventional ultrasound imaging, such as portability, real-time imaging, and cost-effectiveness, with the ability to quantitatively assess tissue mechanical properties by measuring shear wave propagation. These measurements enable not only the detection and monitoring of disease progression but also the guidance of therapeutic interventions and the evaluation of tissue response to treatment. This research expands the application of ultrasound shear wave elastography techniques to several clinically relevant challenges. In aim 1, a miniaturized source of longitudinal shear wave is investigated to enable intracardiac measurement of myocardial stiffness for heart failure therapy guidance. In aim 2, shear wave elasticity imaging is used to detect early biomechanical changes associated with skin breakdown and implant exposure following subcutaneous implantation. Finally, in aim 3, shear wave elasticity imaging is applied to assess the risk of reherniation after patch repair of congenital diaphragmatic hernia.