Simulation study of axial ultrasonic wave propagation in heterogeneous bovine cortical bone

Abstract

The effect of the heterogeneity of the long cortical bone is an important factor when applying the axial transmission technique. In this study, the axial longitudinal wave velocity distributions in specimens from the mid-shaft of a bovine femur were measured, in the MHz range. Bilinear interpolation and the piecewise cubic Hermite interpolating polynomial method were used to construct three-dimensional (3D) axial velocity models with a resolution of 40 μm. By assuming the uniaxial anisotropy of the bone and using the results of previous experimental studies [Yamato, Matsukawa, Yanagitani, Yamazaki, Mizukawa, and Nagano (2008b). Calcified Tissue Int. 82, 162-169; Nakatsuji, Yamamoto, Suga, Yanagitani, Matsukawa, Yamazaki, and Matsuyama (2011). Jpn. J. Appl. Phys. 50, 07HF18], the distributions of all elastic moduli were estimated to obtain a 3D heterogeneous bone model and a uniform model. In the heterogeneous model, moduli at the surface were smaller than those inside the model. The elastic finite-difference time-domain method was used to simulate axial ultrasonic wave propagation in these models. In the heterogeneous model, the wavefront of the first arriving signal (FAS) was dependent on the heterogeneity, and the FAS velocity depended on the measured position. These phenomena were not observed in the uniform model.

Axial transmission technique for screening bucked shin in a horse leg

“…[22][23][24] Using the results of the six-ring samples, a digital bone model in the axial direction was created, as shown in Fig. 4(b), following the study conducted by Hata et al 22) 2.2.3. Estimation of elastic moduli.…”

Simulation study of axial ultrasound transmission in heterogeneous cortical bone model

“…A 3D simulation model was constructed on the basis of the results of our former studies. 16) First, the distribution of the longitudinal wave velocity in the axial direction was experimentally measured with a spatial resolution of 1 mm. Figure 1 shows a specimen of bovine cortical bone.…”

“…15) In this study, we examined the effects of the heterogeneity of bone on the ultrasound propagation by the AT technique. Using an experimental data of an actual bovine cortical bone, 16) we constructed a three-dimensional (3D) model of bone with anisotropic and heterogeneous elasticity. We studied the ultrasonic wave propagation in this model using a finite-difference time-domain (FDTD) method.…”

Computational modeling of long bones during the fracture healing process

“…However, DEXA is not able to directly assess changes in the bone microarchitecture due to osteoporosis such as the increase in cortical porosity which is considered as a good indicator of bone fragility. Also, DEXA is not suitable for mass screenings as it requires specialists, and involves weak exposure to X-ray radiation (Hata et al, 2016). With the development of non-invasive imaging techniques such as computed tomography (CT), μ-CT, and HR-pQCT, imaging of the bone architecture provides important information about age-related changes in bone microstructure and estimates of bone strength.…”

“…Foiret et al, 2014;Talmant, 2009). The FAS velocity and attenuation have been used as the main quantitative parameters for bone characterization(Hata et al, 2016;Baron et al, 2007;Potsika et al, 2016a;Barbieri et al, 2011). However, when the wavelength is comparable to or smaller than the thickness of the cortex, the FAS propagates as a lateral wave reflecting only material and geometrical changes in the cortical surface.…”