Shear Waves are waves that travel perpendicular to the direction of the sound beam. During an ultrasound examination, shear waves are generated and transmitted into the body using the ultrasound probe. These waves travel through the tissue and their speed of propagation is influenced by the tissue's stiffness. Softer tissues allow the shear waves to travel faster, while stiffer tissues slow them down.
By analyzing the speed of shear waves, ultrasound systems can provide quantitative measurements of tissue stiffness, known as shear wave elastography. This technique is particularly useful in assessing the stiffness of organs like the liver, breast, thyroid, and muscles.
Shear wave ultrasound elastography has various applications in clinical practice. For example, it can help identify liver fibrosis, a condition characterized by excessive scarring of the liver tissue. By measuring the liver's stiffness using shear waves, clinicians can assess the severity of fibrosis without the need for invasive procedures like liver biopsies.

Ultrasound elastography is a specialized imaging technique that provides information about tissue elasticity or stiffness. It is used to assess the mechanical properties of tissues, helping to differentiate between normal and abnormal tissue conditions.
The basic principle behind ultrasound elastography involves the application of mechanical stress to the tissue and measuring its resulting deformation. This is typically achieved by using either external compression or shear waves generated by the ultrasound transducer.
There are two main types of ultrasound elastography:
Both strain elastography and shear wave elastography offer valuable insights into tissue characteristics and can assist in the diagnosis and characterization of various conditions. In clinical practice, ultrasound elastography is particularly useful for evaluating liver fibrosis, breast lesions, thyroid nodules, prostate abnormalities, and musculoskeletal conditions. By providing additional information about tissue stiffness, ultrasound elastography enhances the diagnostic capabilities of traditional ultrasound imaging. It allows for non-invasive assessment, improves the accuracy of tissue characterization, and aids in treatment planning and monitoring of various medical conditions.
See also Ultrasound Accessories and Supplies, Sonographer and Ultrasound Technology.