A Monte Carlo method of multiple scattered coherent light with the information of shear wave propagation in scattering media is presented.The established Monte-Carlo algorithm is mainly relative to optical phase varia...A Monte Carlo method of multiple scattered coherent light with the information of shear wave propagation in scattering media is presented.The established Monte-Carlo algorithm is mainly relative to optical phase variations due to the acoustic-radiation-force shear-wave-induced displacements of light scatterers.Both the distributions and temporal behaviors of optical phase increments in probe locations are obtained.Consequently,shear wave speed is evaluated quantitatively.It is noted that the phase increments exactly track the propagations of shear waves induced by focus-ultrasound radiation force.In addition,attenuations of shear waves are demonstrated in simulation results.By using linear regression processing,the shear wave speed,which is set to 2.1 m/s in simulation,is estimated to be 2.18 m/s and 2.35 m/s at time sampling intervals of 0.2 ms and 0.5 ms,respectively.展开更多
We concentrate on the nondissipative mechanism induced shear wave in inhomogenous tissue.The shear wave equation of radiation force in inhomogeneous media is solved numerically with a finite-difference time-domain met...We concentrate on the nondissipative mechanism induced shear wave in inhomogenous tissue.The shear wave equation of radiation force in inhomogeneous media is solved numerically with a finite-difference time-domain method.A rarely studied nondissipative mechanism of shear displacement due to a smooth medium inhomogeneity is evaluated.It is noted that unlike the dissipative effect,the nondissipative action on a localized inhomogeneity with its hardness parameter changing smoothly along the beam axis,compresses or stretches the focus area.The shear waves in nondissipative inhomogeneous media remain the property of sharp turn with 100% peak positive displacement and 64% peak negative displacement.This action is useful in discerning the water-like lesion.展开更多
基金Supported by the National Basic Research Program of China(2010CB732603,2011CB707903)the National Natural Science Foundation of China(30970828).
文摘A Monte Carlo method of multiple scattered coherent light with the information of shear wave propagation in scattering media is presented.The established Monte-Carlo algorithm is mainly relative to optical phase variations due to the acoustic-radiation-force shear-wave-induced displacements of light scatterers.Both the distributions and temporal behaviors of optical phase increments in probe locations are obtained.Consequently,shear wave speed is evaluated quantitatively.It is noted that the phase increments exactly track the propagations of shear waves induced by focus-ultrasound radiation force.In addition,attenuations of shear waves are demonstrated in simulation results.By using linear regression processing,the shear wave speed,which is set to 2.1 m/s in simulation,is estimated to be 2.18 m/s and 2.35 m/s at time sampling intervals of 0.2 ms and 0.5 ms,respectively.
基金Supported by the National Basic Research Program of China under Grant Nos 2010CB732603 and 2011CB707903the National Natural Science Foundation of China under Grant No 30970828.
文摘We concentrate on the nondissipative mechanism induced shear wave in inhomogenous tissue.The shear wave equation of radiation force in inhomogeneous media is solved numerically with a finite-difference time-domain method.A rarely studied nondissipative mechanism of shear displacement due to a smooth medium inhomogeneity is evaluated.It is noted that unlike the dissipative effect,the nondissipative action on a localized inhomogeneity with its hardness parameter changing smoothly along the beam axis,compresses or stretches the focus area.The shear waves in nondissipative inhomogeneous media remain the property of sharp turn with 100% peak positive displacement and 64% peak negative displacement.This action is useful in discerning the water-like lesion.
