Local Phase Velocity Based Imaging of Viscoelastic Phantoms and Tissues

Piotr Kijanka, Matthew W. Urban

Research output: Contribution to journalArticlepeer-review

Abstract

Assessment of soft tissue elasticity and viscosity is of interest in several clinical applications. In this study, we present the feasibility of the local phase velocity based imaging (LPVI) method to create images of phase velocity and viscoelastic parameters in viscoelastic tissue-mimicking materials and soft tissues. In viscoelastic materials, it is necessary to utilize wave-mode isolation using a narrow bandpass filter combined with a directional filter in order to robustly reconstruct phase velocity images with LPVI in viscoelastic media over a wide range of frequencies. A pair of sequential focused acoustic radiation force push beams, focused once on the left-hand side and once on the right-hand side of the probe, was used to produce broadband propagating shear waves. The local shear wave phase velocity is then recovered in the frequency domain for multiple frequencies, for both acquired data sets. Then, a 2-D shear wave velocity map is reconstructed by combining maps from two separate acquisitions. By testing the method on simulated data sets and performing in vitro phantom and in vivo liver tissue experiments, we show the ability of the proposed technique to generate shear wave phase velocity maps at various frequencies in viscoelastic materials. Moreover, a nonlinear least-squares problem is solved in order to locally estimate elasticity and viscosity parameters. The LPVI method with added directional and wavenumber filters can produce phase velocity images, which can be used to characterize the viscoelastic materials.

Original languageEnglish (US)
Article number8963899
Pages (from-to)389-405
Number of pages17
JournalIEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
Volume68
Issue number3
DOIs
StatePublished - Mar 2021

Keywords

  • Acoustic radiation force
  • imaging
  • inclusion
  • Kelvin-Voigt (KV) model
  • local wavenumber
  • phantom
  • phase velocity
  • shear wave elastography (SWE)
  • soft tissue
  • ultrasound
  • viscoelastic

ASJC Scopus subject areas

  • Instrumentation
  • Acoustics and Ultrasonics
  • Electrical and Electronic Engineering

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