Methods and approaches in ultrasound elastography

Abstract

Medical ultrasound is one of the most common medical imaging modalities. It allows real-time visualization of the morphology of soft tissues in the human body based on backscattered compression waves in the high-frequency (MHz) range. Special technologies are sensitive to organ functions such as blood flow and tissue strain. Over the past decade, ultrasound-based elastography (USE) has been developed and became widely applied in the clinic for the assessment of tissue stiffness in a variety of conditions including malignant tumors and liver fibrosis. The clinical benefit of USE has been overwhelmingly demonstrated in a large number of clinical studies and reviews. Unlike other sonographic methods, USE is not a single technique but rather a set of methodological ideas and approaches centered on the mechanical stimulation of soft tissues, deformation readout, and stiffness reconstruction. This chapter provides an overview of the key concepts of current USE methods and their potential clinical applications. Many of the methods discussed are still experimental, while others have already been replaced by more sophisticated quantitative and image-resolved methods. The aim of this chapter is to guide readers through the pros and cons of individual concepts, thereby helping them to gain insight into the basic principles of USE.