Acoustic-radiation-force-induced shear wave propagation in cardiac tissue

2009 ◽  
Author(s):  
Richard R. Bouchard ◽  
Patrick D. Wolf ◽  
Stephen J. Hsu ◽  
Douglas M. Dumont ◽  
Gregg E. Trahey
Keyword(s):  
Wave Propagation ◽  
Shear Wave ◽  
Cardiac Tissue ◽  
Acoustic Radiation ◽  
Radiation Force ◽  
Acoustic Radiation Force

scholarly journals Optical Coherence Tomography Detection of Shear Wave

2021 ◽  
Author(s):  
Marjan Razani
Keyword(s):  
Wave Propagation ◽  
Titanium Dioxide ◽  
Shear Wave ◽  
Acoustic Radiation ◽  
Radiation Force ◽  
Sine Wave ◽  
Acoustic Radiation Force ◽  
Optical Coherence ◽  
Swept Source ◽  
Wave Speeds

In this work, we explored the potential of measuring shear wave propagation using Optical Coherence Elastography (OCE). Shear waves were generated using a 20 MHz piezoelectric transducer transmitting sine-wave bursts of 400 μs, synchronized with the OCT swept source wavelength sweep. The acoustic radiation force was applied to two gelatin phantoms (differing in gelatin concentration by weight, 8% vs 14%, respectively). Differential OCT phase maps, measured with and without the acoustic radiation force, demonstrate microscopic displacement generated by shear wave propagation in these phantoms of different stiffness. The shear wave speeds for the 14% and 8% gelatin-titanium dioxide phantoms were 2.24 0.06 m/s and 1.49 0.05 m/s and also the shear modulus estimated using SW-OCE was 5.3±0.2 kPa and 2.3±0.1 kPa for the 14% and 8% gelatin-titanium dioxide phantoms, respectively. The results demonstrate the feasibility of this technique for measuring the mechanical properties of tissue.

scholarly journals Mathematical modelling of acoustic radiation force in transient shear wave elastography in the heart

2020 ◽  
Vol 54 (6) ◽  
pp. 2319-2350
Author(s):  
Federica Caforio ◽  
Sébastien Imperiale
Keyword(s):  
Wave Propagation ◽  
Asymptotic Analysis ◽  
Small Parameter ◽  
Shear Wave ◽  
Pressure Wave ◽  
Acoustic Radiation ◽  
Excitation Frequency ◽  
Radiation Force ◽  
Cardiac Mechanics ◽  
Acoustic Radiation Force

The aim of this work is to provide a mathematical model and analysis of the excitation and the resulting shear wave propagation in acoustic radiation force (ARF)-based shear wave cardiac elastography. Our approach is based on asymptotic analysis; more precisely, it consists in considering a family of problems, parametrised by a small parameter inversely proportional to the excitation frequency of the probes, the viscosity and the velocity of pressure wave propagation. We derive a simplified model for the expression of the ARF by investigating the limit behaviour of the solution when the small parameter goes to zero. By formal asymptotic analysis – an asymptotic expansion of the solution is used – and energy analysis of the nonlinear elastodynamic problem, we show that the leading-order term of the expansion is solution of the underlying, incompressible, nonlinear cardiac mechanics. Subsequently, two corrector terms are derived. The first is a fast-oscillating pressure wave generated by the probes, solution of a Helmholtz equation at every time. The second corrector term consists in an elastic field with prescribed divergence, having a function of the first corrector as a source term. This field corresponds to the shear acoustic wave induced by the ARF. We also confirm that, in cardiac mechanics, the presence of viscosity in the model is essential to derive an expression of the shear wave propagation from the ARF, and that this phenomenon is related to the nonlinearity of the partial differential equation.

scholarly journals Concurrent Visualization of Acoustic Radiation Force Displacement and Shear Wave Propagation with 7T MRI

PLoS ONE ◽  
2015 ◽  
Vol 10 (10) ◽  
pp. e0139667 ◽  
Author(s):  
Yu Liu ◽  
Brett Z. Fite ◽  
Lisa M. Mahakian ◽  
Sarah M. Johnson ◽  
Benoit Larrat ◽  
...  
Keyword(s):  
Wave Propagation ◽  
Shear Wave ◽  
Acoustic Radiation ◽  
Radiation Force ◽  
Acoustic Radiation Force ◽  
Force Displacement
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