Influence of cancellous bone microstructure on ultrasonic attenuation: a theoretical prediction

Abstract

BackgroundQuantitative ultrasound has been used for the assessment of cancellous bone status. The attenuation mechanisms of cancellous bone, however, have not been well understood, because the microstructure of cancellous bone is significantly inhomogeneous and the interaction between ultrasound and the microstructure of cancellous bone is complex. In this study, a theoretical approach was applied to investigate the influence of the microstructure of cancellous bone on ultrasonic attenuation.ResultsThe scattering from a trabecular cylinder was significantly angle dependent. The dependencies of the ultrasonic attenuation on frequency, scatterer size, and porosity were explored from the theoretical calculation. Prediction results showed that the ultrasonic attenuation increased with the increase of frequency and decreased linearly with the increase in porosity, and the broadband ultrasound attenuation decreased with the increase in porosity. All these predicted trends were consistent with published experimental data. In addition, our model successfully explained the principle of broadband ultrasound attenuation measurement (i.e., the attenuation over the frequency range 0.3–0.65 MHz was approximately linearly proportional to frequency) by considering the contributions of scattering and absorption to attenuation.ConclusionThe proposed theoretical model may be a potentially valuable tool for understanding the interaction of ultrasound with cancellous bone.

Increased Fat Mass Leads To Bone Loss, A Prospective Short-Term, 18-Week Study In Young Healthy Men Undergoing Basic Training of The Swiss Army

“…We used a calcaneal site QUS device (Sonost-3000, medical ECONET, Oberhausen, Germany) which measured the velocity of sound waves as the speed of sound (SOS in m/s) and the attenuation after passing the bone as bone ultrasound attenuation (BUA in dB/MHz). In the range of the ultrasound measurements (between 0.3 and 0.65 MHz), theoretical calculations illustrated a linear function of attenuation dependent on frequency, and a linear positive correlation between BUA and density (32). This observation was also observed in experimental studies (18,33,34).…”

“…regular breaks for subsistence) and/or a higher stress level could have additional negative effects on weight and fat mass (42). Worryingly, after the 18-week follow-up, a change in the bone is visible with a signi cant decrease in the attenuation of the sound, which is synonymous with loss of bone substance (23,24,32). Interestingly, there was a direct correlation between loss of bone and the increase in fat mass, which means that the increase in fat mass in the 18 weeks already harmed the bone status.…”

Feasibility analysis of an ultrasound on line diagnostic approach for oral and bone surgery

“…Moreover, it is also worth to consider that the solid mineralized trabecular network could give rise to scattering phenomena, thus introducing strong attenuation to the acoustic waves propagating through the bone. In this regard, it is important to underline that the scattering is strongly dependent on the acoustic wavelength and thus on the operating frequency 32 , 49 . The mechanical properties used in our model, averagely describe both the cortical bone and the trabeculae constituting the structure of the cancellous bone 39 , 40 , giving rise to a speed of sound c b = 2985 m/s, which, without loss of generality, well describe the waves propagating in cortical bone and the fast wave propagating in the wet cancellous bone 47 , 48 .…”

“…This velocity value corresponds to a wavelength of about 30 mm at a frequency of 100 kHz, therefore, in the range of frequencies considered in this analysis, the elements constituting the cancellous bone have a dimension much smaller that the acoustic wavelength. Based on this consideration, we considered negligible the scattering effects 32 , 49 , modeling the bone as a homogenous medium.…”

Investigation of the Effect of the Skull in Transcranial Photoacoustic Imaging: A Preliminary Ex Vivo Study

“…Moreover, among the three quantitative measures, image distortion and the lack of smoothness are the major consequences of the diploe layer that constitutes the majority thickness of thick bones, whereas image average intensity attenuation is the consequence of the cortical layer [ 51 , 52 , 76 , 77 , 78 , 79 ]. In other words, blocking the optical path more significantly contributes to the amplitude decay, while blocking the acoustic propagation path contributes mainly to the distortion of the morphological map of the imaging target [ 29 , 52 , 80 , 81 ]. The combined significant acoustic distortion in the diploe layer and the optical attenuation in the cortical–diploe or cortical–tissue interfaces make the use of photoacoustic transcranial imaging challenging in animals with thicker skulls or in humans.…”