“…Cortical bone may generally be considered to be solid; cancellous bone consists of a complex open-celled porous network of rod-and plate-shaped elements termed trabeculae. In order to understand the dependence of ultrasound propagation, in particular, upon the material and structural properties of cancellous bone, Biot-based theories have been used extensively [1][2][3][4][5][6][7][8][9]. Biot theory predicts two compressional waves, often referred to as 'fast' and 'slow', when the waves propagating through the solid frame of bone and marrow are in-phase and out-of-phase respectively, and a shear wave.…”