In:
The Journal of the Acoustical Society of America, Acoustical Society of America (ASA), Vol. 112, No. 5_Supplement ( 2002-11-01), p. 2404-2405
Abstract:
Transient elastography allows one to accurately achieve the Youngs modulus of soft tissues from the measurement of the shear-wave velocity. The Youngs modulus is a second-order elastic moduli and describes the linear behavior of a medium. In order to achieve the third-order elastic moduli in soft tissues (which characterize the nonlinearity), we have used transient elastography in an acoustoelasticity-like experiment. It consists in measuring shear-wave velocities in a uniaxial pre-stressed medium. This technique uses an ultrafast scanner and allows one to measure thenonlinear third-order elastic Landau coefficients A, B, C in an Agar-gelatin based phantom. The several orders of magnitude found between these three constants appear to be a characteristic of soft tissues. In a second part, we present the first experimental displacements of a finite amplitude transverse wave. The results are compared to a simulation based on the modified Burgers equation. In both approaches, it appears that contrary to longitudinal wave for which even harmonics are created during the propagation, only odd harmonics are present on the displacement spectra of a finite amplitude transverse wave.
Type of Medium:
Online Resource
ISSN:
0001-4966
,
1520-8524
Language:
English
Publisher:
Acoustical Society of America (ASA)
Publication Date:
2002
detail.hit.zdb_id:
1461063-2
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