Acoustic shear wave displacement measurement using ultrasound

Echo ultrasound can be used to detect and measure acoustic shear waves. Earlier it has been shown that a phase contrast based magnetic resonance imaging technique can be used for cyclic shear wave displacement measurement. Echo ultrasound presents an alternate method for imaging of such shear waves. The ultrasound based method uses the phase of quadrature echo signals to estimate the local displacements due to shear wave propagation and allows for real-time measurement of such displacements. The shear wave displacements were measured in tissue-mimicking gel phantom specimens and beef muscle specimens. From the displacement measurements of propagating waves, it is possible to estimate the local wave speed using local frequency estimation techniques. The wave speeds can be used to characterize the material under investigation in terms of shear modulus and dispersion. These shear wave parameters can thus provide additional tissue characterization tools