Ultrasound-based shear wave evaluation in transverse isotropic tissue mimicking phantoms and muscle

Ultrasound radiation force-based methods often neglect the inherent anisotropy nature of tissue. Measurements were made in four cube-shaped phantoms composed of fibrous or fishing line material embedded in 8% and 14% gelatin concentrations and in pork tenderloin. Measurements were made at different angles relative to the transducer. For the fibrous phantom, the mean and standard deviations of the shear wave speeds for 8% and 14% gelatin along the fibers were (3.60 ± 0.03 and 4.10 ± 0.11 m/s) and across the fibers were (3.18 ± 0.12 and 3.90 ± 0.02 m/s), respectively. For the fishing line material phantom the shear wave speeds for 8% and 14% gelatin along the fibers were (2.86 ± 0.20 and 3.40 ± 0.09 m/s) and across the fibers were (2.44 ± 0.24 and 2.84 ± 0.14 m/s), respectively. For the pork muscle, the shear wave speeds along the fibers at two different locations were (3.83 ± 0.16 and 3.86 ± 0.12 m/s) and across the fibers were (2.73 ± 0.18 and 2.70 ± 0.16 m/s), respectively. The fibrous gelatin-based phantoms and the fishing line gelatinbased phantoms exhibited anisotropy that resembles that observed in pork muscle.