Heterogeneous ultrasonic wave properties in leg cortical bones of Thoroughbreds

Safe and inexpensive diagnosis of leg bone disease in the field is very important for Thoroughbreds and large animals, because large animals are difficult to transport, and prompt diagnosis is required. The quantitative ultrasound (QUS) is attracting attention for the evaluation of leg bones because it can give us information of elasticity, which is related to the bone quality. For the development of a QUS system of animal leg bones, understanding of characteristic ultrasonic wave properties (velocity and attenuation) is a key issue. Therefore, wave properties in Thoroughbreds’ leg bones were obtained experimentally using an ultrasonic pulse technique. Precise measurements showed clear heterogeneity of ultrasonic wave properties due to the location. Opposed to the other large animals like bovines, high wave velocities were found in the medial and lateral parts, which possibly tells the effects of hard training in the fields. From a clinical perspective, the medial and lateral parts are less prone to diseases such as periostitis. The attenuation was greater in the posterior part, especially in the porous area near the trabecular bone. We also found that attenuation depended on bone matrix. Further investigation is necessary to discuss on the heterogeneity of wave properties in detail.