Detection of elastic guided waves using an axial transmission method: Performance comparison between PZT and cMUT technologies

Following recent advances in medical ultrasound imaging modalities, almost all human tissues can currently be examined. However, there is one exception: the human skeleton. Recent results have shown that cortical bone behaves like an elastic waveguide [1] for this organ supporting the propagation of several guided modes, depending on the cortical waveguide thickness and elasticity, can propagate. This therefore offers a new opportunity perspectives to quantify quantitative assessment factors of fracture risk-related bone quality characteristics and thus to predict risk of fracture. The cMUT large frequency bandwidth compared to the PZT is expected to reach important improvements for cortical bone assessment. In a previous paper [2] the potential of cMUT technology to detect and measure elastic guided waves, using an axial transmission technique, was demonstrated. The work reported here is an extension of our previous developments and investigates more thoroughly the comparison between the cMUT and PZT technologies.