Corrections to "The Role of Viscosity in the Impulse Diffraction Field of Elastic Waves Induced by the Acoustic Radiation Force" and "Supersonic Shear Imaging: A New Technique for Soft Tissue Elasticity Mapping"

Abstract

This article presents corrections to J. Bercoff et al., "The role of viscosity in the impulse diffraction field of elastic waves induced by the acoustic radiation force," IEEE Trans. Ultrason., Ferroelectr., Freq. Control, vol. 51, no. 11, pp. 1523-1536, Nov. 2004, and J. Bercoff et al., "Supersonic shear imaging: A new technique for soft tissue elasticity mapping," IEEE Trans. Ultrason., Ferroelectr., Freq. Control, vol. 51, no. 4, pp. 396-409, Apr. 2004.

Fig. 1.

The incorrect and correted g_zz Green’s function is plotted as a function of time at four different spatial positions in (a)–(d). For all plots, the source-observer distance is 1 cm and the angle speficied by θ denotes the polar angle from the direction of propagation of the observer position in spherical coordinates. For example, the θ = 90° plot in (a) corresponds to g_zz measured 1 cm from the origin in the z = 0 plane. For all plots, the following medium parameters were used: c_s = 1.5 m/s, c_p = 1500 m/s, ρ = 1000 kg/m³, η_p = 0, and η_s = 2 Pa · s, where c_s is the shear velocity, c_p is the bulk velocity, ρ is the density, η_p is the bulk viscosity, and η_s is the shear viscosity. Conceptually, g_zz can be interpreted as the displacement along the direction z generated by a impulse forcing function along z applied at the origin at time t = 0.