Correlations of the Phase Velocity and the Dispersion with the Bone Mineral Density and the Architectural Parameters in Bovine Trabecular Bone

The present study aims to investigate the correlations of the phase velocity and the dispersion (the dispersion rate and the frequency dependence of the phase velocity) with the bone mineral density (BMD) and the architectural parameters (the bone volume fraction, the trabecular thickness, and the trabecular separation) in bovine trabecular bone in vitro. The frequency-dependent phase velocity, the dispersion rate, and the frequency dependence were measured over a frequency range from 0.2 to 0.6 MHz in 22 bovine femoral trabecular bone samples. The phase velocity and the dispersion rate showed significant correlations with the BMD and the architectural parameters. In contrast, the frequency dependence of the phase velocity was found to exhibit very weak correlations with the BMD and the architectural parameters. The stratified model for wave propagation in alternating parallel solid-fluid layers successfully predicted the variations of the phase velocity with the architectural parameters observed in the 22 bone samples.