Work

Nonlinear Shear Modulus Estimation With Bi-Axial Motion Registered Local Strain

Year: 2019

Type: article

Abstract: Nonlinear elasticity imaging provides additional information about tissue behavior that is potentially diagnostic and avoids errors inherent in applying a linear elastic model to tissue under large strains. Nonlinear elasticity imaging is challenging to perform due to the large deformations required to obtain sufficient tissue strain to elicit nonlinear behavior. This work uses a method of axial and lateral displacement tracking to estimate local axial strain with simultaneous measurement of shear modulus at multiple compression levels. By following the change in apparent shear modulus and the stress deduced from the strain maps, we are able to accurately quantify nonlinear shear modulus (NLSM). We have validated our technique with a mechanical NLSM measurement system. Our results demonstrate that 2-D tracking provides more consistent NLSM estimates than those obtained by 1-D (axial) tracking alone, especially where lateral motion is significant. The elastographic contrast-to-noise ratio in heterogeneous phantoms was 12.5%-60% higher using our method than that of 1-D tracking. Our method is less susceptible to mechanical variations, with deviations in mean elastic values of 2%-4% versus 5%-37% for 1-D tracking.

Source: IEEE Transactions on Ultrasonics Ferroelectrics and Frequency Control

DOI: 10.1109/tuffc.2019.2919600

Authors: Soumya Goswami, Rifat Ahmed, Marvin M. Doyley, Stephen A. McAleavey

Institution: University of Rochester

Language: English

Topic: Ultrasound Imaging and Elastography

Subfield: Radiology, Nuclear Medicine and Imaging

Field: Medicine

Domain: Health Sciences

Open Access status: green

Funders: National Institutes of Health, National Institute of Biomedical Imaging and Bioengineering

Awards: Quantification of Shear Wave Strain Dependence in Breast Tissues, G6884496737