Elastography: A Quantitative Method for Imaging the Elasticity of Biological Tissues

TLDR

The authors introduce a quantitative imaging method for strain and elastic modulus distributions in soft tissues and outline its potential clinical applications. The method employs external compression, cross‑correlation of pre‑ and post‑compression A‑line pairs to compute strain profiles along the transducer axis, and converts these to elastic modulus profiles by measuring applied stresses and correcting for nonuniform stress fields. Initial phantom and excised animal tissue experiments demonstrate that the technique can quantitatively image strain and elastic modulus distributions with good resolution, sensitivity, and reduced speckle.

Abstract

We describe a new method for quantitative imaging of strain and elastic modulus distributions in soft tissues. The method is based on external tissue compression, with subsequent computation of the strain profile along the transducer axis, which is derived from cross-correlation analysis of pre- and post-compression A-line pairs. The strain profile can then be converted to an elastic modulus profile by measuring the stresses applied by the compressing device and applying certain corrections for the nonuniform stress field. We report initial results of several phantom and excised animal tissue experiments which demonstrate the ability of this technique to quantitatively image strain and elastic modulus distributions with good resolution, sensitivity and with diminished speckle. We discuss several potential clinical uses of this technique.