Parameters affecting the resolution and accuracy of 2-D quantitative shear wave images.

Journal Article

Time-of-flight methods allow quantitative measurement of shear wave speed (SWS) from ultrasonically tracked displacements following impulsive acoustic radiation force excitation in tissue. In heterogeneous materials, reflections at boundaries can distort the wave shape and confound determination of the wave arrival time. The magnitude of these effects depends on the shear wavelength of the excitation, the kernel size used to calculate the SWS, and the method used to determine the wave arrival time. In this study, we perform a parametric analysis of these factors using finite element modeling of the tissue response and simulated ultrasonic tracking. Two geometries are used, a stiff vertical layer and a stiff spherical inclusion, each in a uniform background. Wave arrival times are estimated using the peak displacement, peak slope of the leading edge, and cross-correlation methods. Results are evaluated in terms of reconstruction accuracy, resolution, contrast, and contrast-to-noise ratio of reconstructed SWS images. Superior results are obtained using narrower excitation widths and arrival time estimators which identify the leading edge of the propagating wave. The optimal kernel size is determined by a tradeoff between improved accuracy for larger kernels at the expense of spatial resolution.

Full Text

Duke Authors

Cited Authors

  • Rouze, NC; Wang, MH; Palmeri, ML; Nightingale, KR

Published Date

  • August 2012

Published In

Volume / Issue

  • 59 / 8

Start / End Page

  • 1729 - 1740

PubMed ID

  • 22899119

Electronic International Standard Serial Number (EISSN)

  • 1525-8955

Digital Object Identifier (DOI)

  • 10.1109/TUFFC.2012.2377

Language

  • eng

Conference Location

  • United States