Dependence of the phase velocity on the structural properties in trabecular bone

초록

The present study considers a stratified model for wave propagation in periodically stratified media consisting of alternating, parallel, solid-fluid layers in order to gain insight into ultrasonic wave propagation in trabecular bone. The stratified model was applied to predict the dependence of the phase velocity on the structural properties, such as trabecular thickness (Tb.Th), spacing (s) and volume fraction (VF), in trabecular bone. The stratified model predicted that the phase velocity would increase monotonically with Tb.Th and VF, but decreases with s. The predictions of the model were, found to be consistent with the previously published measurements in trabecular-bone-mimicking phantoms consisting of two-dimensional arrays of parallel nylon wires. The structural difference, between the model and the nylon wire phantoms resulted in a significant, discrepancy ill the phase velocity versus VF. Incorporating a new definition of VF, which is more suitable to the structure of the phantoms, into the stratified model significantly improved its ability to predict the dependence of the phase velocity on VF. The modified stratified model also showed good agreement with the previously published measurements in the human calcaneus in vitro.

키워드