
Accounting for the Spatial Observation Window in the 2-D Fourier Transform Analysis of Shear Wave Attenuation.
Recent measurements of shear wave propagation in viscoelastic materials have been analyzed by constructing the 2-D Fourier transform (2DFT) of the shear wave signal and measuring the phase velocity c(ω) and attenuation α(ω) from the peak location and full width at half-maximum (FWHM) of the 2DFT signal at discrete frequencies. However, when the shear wave is observed over a finite spatial range, the 2DFT signal is a convolution of the true signal and the observation window, and measurements using the FWHM can yield biased results. In this study, we describe a method to account for the size of the spatial observation window using a model of the 2DFT signal and a non-linear, least-squares fitting procedure to determine c(ω) and α(ω). Results from the analysis of finite-element simulation data agree with c(ω) and α(ω) calculated from the material parameters used in the simulation. Results obtained in a viscoelastic phantom indicate that the measured attenuation is independent of the observation window and agree with measurements of c(ω) and α(ω) obtained using the previously described progressive phase and exponential decay analysis.
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Related Subject Headings
- Viscosity
- Signal Processing, Computer-Assisted
- Phantoms, Imaging
- Fourier Analysis
- Finite Element Analysis
- Elasticity Imaging Techniques
- Elasticity
- Elastic Modulus
- Algorithms
- Acoustics
Citation

Published In
DOI
EISSN
ISSN
Publication Date
Volume
Issue
Start / End Page
Related Subject Headings
- Viscosity
- Signal Processing, Computer-Assisted
- Phantoms, Imaging
- Fourier Analysis
- Finite Element Analysis
- Elasticity Imaging Techniques
- Elasticity
- Elastic Modulus
- Algorithms
- Acoustics