Numerical Characterization of Shear Elasticity Values Estimated with the Time-of-Flight Approach

Luke M. Wiseman, Matthew W. Urban, Robert J. McGough

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

In clinical ultrasound applications, there is a need for accurate estimates of the shear elasticity, which is directly relevant to the characterization of liver fibrosis, cancer, and other pathologies. The time-of-flight (TOF) approach, which is widely used for estimating the shear elasticity, is effective in purely elastic media, but the TOF approach tends to overestimate the shear elasticity in viscoelastic shear wave phantoms and in soft tissues. To determine the range of shear viscosity values over which the TOF approach yields accurate estimates for the shear elasticity, multiple three-dimensional (3D) simulations of the acoustic radiation force and resulting shear wave particle displacement are assessed. The TOF method is evaluated for values of shear elasticity and shear viscosity within the range of values encountered in healthy liver tissue. A realistic 3D model of the acoustic radiation force is calculated using the fast nearfield method and the angular spectrum approach in FOCUS (https://www.egr.msu.edu/~fultras-web), and then the shear waves are simulated in 3D with Green's functions in viscoelastic media on a graphics processing unit (GPU). The TOF method is evaluated within a two-dimensional (2D) cross-section and is based on the Kelvin-Voigt model for a viscoelastic material. The results demonstrate that the accuracy of the TOF method is dependent on the shear elasticity and the shear viscosity, where the accuracy of the TOF method worsens as the shear viscosity increases within the ranges encountered in liver and also worsens as the elasticity increases for a fixed value of shear viscosity.

Original languageEnglish (US)
Title of host publication2019 IEEE International Ultrasonics Symposium, IUS 2019
PublisherIEEE Computer Society
Pages1387-1390
Number of pages4
ISBN (Electronic)9781728145969
DOIs
StatePublished - Oct 2019
Event2019 IEEE International Ultrasonics Symposium, IUS 2019 - Glasgow, United Kingdom
Duration: Oct 6 2019Oct 9 2019

Publication series

NameIEEE International Ultrasonics Symposium, IUS
Volume2019-October
ISSN (Print)1948-5719
ISSN (Electronic)1948-5727

Conference

Conference2019 IEEE International Ultrasonics Symposium, IUS 2019
CountryUnited Kingdom
CityGlasgow
Period10/6/1910/9/19

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ASJC Scopus subject areas

  • Acoustics and Ultrasonics

Cite this

Wiseman, L. M., Urban, M. W., & McGough, R. J. (2019). Numerical Characterization of Shear Elasticity Values Estimated with the Time-of-Flight Approach. In 2019 IEEE International Ultrasonics Symposium, IUS 2019 (pp. 1387-1390). [8925789] (IEEE International Ultrasonics Symposium, IUS; Vol. 2019-October). IEEE Computer Society. https://doi.org/10.1109/ULTSYM.2019.8925789