Heterogeneity of ultrasonic wave properties in ex vivo cortical bone of racehorse.

Despite the prevalence of lower limb disease in racehorses, outdoor bone evaluation equipment is lacking. Consequently, a secure and cost-effective field screening system for bones is required to identify early-stage leg illness. Elastic stiffness cannot be measured using x-ray techniques and is closely associated with bone quality, which is recognized as a significant determinant of fracture risk. Quantitative ultrasound has garnered attention as a viable option, offering insights into elastic stiffness. Understanding the characteristic behaviors of ultrasonic wave properties (velocity, attenuation, and associated characteristics) is crucial for developing a quantitative ultrasound system using simulations and plays a significant role in clinical evaluation. This study experimentally assessed the wave properties of thoroughbred leg bone utilizing an ultrasonic pulse technique in the megahertz range, using ex vivo specimens. The bone exhibited uniaxial anisotropy and demonstrated clear heterogeneity in the axial cross section. Exact measurements demonstrated distinct heterogeneity in the ultrasonic properties of the bone. Elevated wave velocities were observed in the medial and lateral regions, demonstrating clinical significance. Attenuation was more pronounced in core regions, suggesting a reliance on porosity. A correlation (R = 0.68, p < 0.001) was found between velocity and attenuation in dense regions, which may be attributable to the bone matrix properties.