Chapter 8 - Lateral and shear strain imaging for ultrasound elastography

Abstract

Elastographic imaging is three-dimensional (3D), with three normal strain tensors, along with associated shear strain components. Majority of the publications and commercial implementations of elastography, however, have focused on only the axial displacement vector and strain tensor component. Applications where lateral and shear strain tensors are necessary include Young's modulus reconstruction, poroelastography, and temperature imaging. In the current practice with two-dimensional (2D) scan planes, only the axial and lateral strain components within this plane have been estimated. With the advent of 2D matrix transducer arrays that provide echo signals over a 3D scan volume, we anticipate estimation of the elevational strain component and corresponding shear strain components to become as common as the current lateral strain estimation methods. Accurate estimation of all the displacement vectors and normal and shear strain tensors will enable quantification of ultrasonographic strain imaging.