Characterization of Anisotropic Lattice Structured Phantoms Using 3D-Rotational Shear Wave Elasticity Imaging (3D-RSWEI)

We present a 3D-RSWEI characterization of anisotropic lattice phantoms. Shear wave speeds versus rotational angle were measured while the lattices were submerged in water and after embedding in a softer, isotropic polyvinyl alcohol cryogel. In both cases, shear wave propagation was anisotropic and fit to an ellipse, with faster wave speeds observed along the material symmetry direction. Measured shear wave speeds and shear anisotropy decreased between lattices in water versus embedded in PVA. Linear wave dispersion slopes were higher along versus across the material symmetry direction. Measured speed of sound was higher and acoustic attenuation was lower than that of biological tissue. These results showcase applicability of 3D-RSWEI to characterize novel anisotropic lattice phantoms.