To facilitate an understanding of the dependence of ultrasound velocity and
attenuation upon the material and structural properties of cancellous bone
, several theoretical concepts for ultrasound propagation have been adapted
or developed, including the Blot theory and several scattering theories. B
lot theory considers wave propagation through an elastic porous solid inter
spersed with fluid, considering the separate motion of the trabecular frame
work and morrow, respectively. The success achieved with the Blot theory ha
s, to date, tended to be greater for the prediction of velocity than for at
tenuation. This article provides a review of the relevant literature, descr
ibing the physical parameters required for the Blot theory and their experi
mental determination. It is suggested that future developments should consi
der additional attenuation mechanisms, in particular, those due to scatteri
ng, local flow in microcracks, and surface roughness of the trabeculae, (C)
1999 by Elsevier Science Inc. All rights reserved.