The non-linear relationship between BUA and porosity in cancellous bone

Abstract

There is growing interest in assessing the clinical value of ultrasound in the prediction and management of osteoporosis. However, the mechanism of ultrasound propagation in cancellous bone is not well understood. The Biot theory is one approach to modelling the interaction of sound waves with cancellous structure, and porosity is one of its input parameters. In this paper we report the relationship between broadband ultrasonic attenuation (BUA) corrected for specimen thickness (nBUA) and porosity in a porous Perspex cancellous bone mimic, a stereolithography cancellous bone mimic and in natural human and bovine tissue. nBUA and porosity have a non-linear parabolic relationship. The maximum nBUA value (nBUAmax) occurs at approximately 30% porosity in the Perspex mimic, approximately 70% in the stereolithography mimic and approximately 75% in natural cancellous bone. We discuss the effect of structure on the form of the nBUA-porosity relationship.

Ultrasonic wave propagation in stereo-lithographical bone replicas

“…A similar fundamental relationship does not exist for BUA. It has been shown however that BUA follows a parabolic-type dependence on porosity having a minimum values corresponding to both solid bone ͑0% porosity͒ and marrow ͑100% porosity͒͑ Hodgskinson et al, 1996͒. Hence, similar BUA values may be obtained for a few marrow pores within a largely solid bone ͑Sasso et al, 2008͒ and a few bony trabeculae within a largely marrow sample. A parameter that follows a similar pattern is the surface area of the bone-marrow interface; associated with this, a linear relationship between BUA and fractal dimension has been demonstrated ͑Langton et al, 1998͒.…”

A Review of the State of Art in Applying Biot Theory to Acoustic Propagation through the Bone

“…A similar fundamental relationship does not exist for BUA. It has been shown however that BUA follows a parabolic-type dependence on porosity having a minimum values corresponding to both solid bone (0% porosity) and marrow (100% porosity) [11]. Hence, similar BUA values may be obtained for a few marrow pores within a largely solid bone and a few bony trabeculae within a largely marrow sample.…”

Ultrasound Simulation in the Distal Radius Using Clinical High-Resolution Peripheral-CT Images

“…BUA is also known to exhibit nonlinear behavior with respect to porosity variations over a sufficiently wide range (Serpe and Rho 1996;Hodgskinson et al 1996). Whether these two findings are related remains to be elucidated.…”

“…301 (with volume fraction = 0.12). As may also be apparent, the latter signal has more high frequency content than the former; this is due to the higher degree of scattering present in the specimen with larger volume fraction which preferentially removes the higher frequency content of the propagating waveform (Serpe and Rho 1996;Hodgskinson et al 1996;Bossy et al 2005;Kaufman et al 2008a). Also shown in Fig.…”