Shear wave elastography with two-dimensional ultrasound transducer.

• Ano de defesa: 2018
• Autor(a) principal: Santos, Djalma Simões dos
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Acoustic radiation force; Array transducer; Diagnóstico por imagem; Elastografia por onda de cisalhamento; Força de radiação acústica; Shear wave elastography; Transdutor de ultrassom; Transdutor matricial; Ultrasound transducer; Ultrassonografia
• Link de acesso: http://www.teses.usp.br/teses/disponiveis/3/3154/tde-01102018-142217/

Chronic liver diseases are the eighth leading cause of death in Brazil and a major public health problem in the world. Liver biopsy is the best available reference standard for evaluating and classifying stages of liver diseases, but it presents limitations and complications that are common in invasive methods. In recent years, elasticity imaging methods have been the focus of intense research activity with the ability to measure mechanical properties of soft tissues in a non-invasive way. Shear wave elastography is one of the most promising methods because it enables to quantitatively assess tissue elasticity. However, the current depth range of shear wave elastography impedes its application in obese patients, which have a great risk of developing liver disease. The aim of this study is to investigate the use of shear wave elastography in deeper tissues using a two-dimensional ultrasound transducer array. An efficient transducer array arrangement was simulated, fabricated and characterized. The results show that the proposed transducer configuration presents enhanced transmitting capabilities for generating tissue displacement in deeper tissues. In addition, numerical simulations were performed in order to track the tissue deformation and reconstruct its elastic properties.