Ten years have passed since the first commercial equipment for elastography was released; since then clinical utility has been demonstrated. Nowadays, most manufacturers offer an elastography option. The most widely available commercial elastography methods are based on strain imaging, which uses external tissue compression and generates images of the resulting tissue strain. However, imaging methods differ slightly among manufacturers, which results in different image characteristics, for example, spatial and temporal resolution, and different recommended measurement conditions. In addition, many manufacturers have recently provided a shear wave-based method, providing stiffness images based on shear wave propagation speed. Each method of elastography is designed on the basis of assumptions of measurement conditions and tissue properties. Thus, we need to know the basic principles of elastography methods and the physics of tissue elastic properties to enable appropriate use of each piece of equipment and to obtain more precise diagnostic information from elastography. From this perspective, the basic section of this guideline aims to support practice of ultrasound elastography.
Keywords: Acoustic radiation force; Elastography; Shear wave; Stiffness; Strain; Tissue elasticity.