Ultrasound propagation through trabecular structures : influence of structure and material

• Κύριος συγγραφέας: Μαντά, Αναστασία
• Άλλοι συγγραφείς: Manta, Anastasia
• Γλώσσα: English
• Έκδοση: 2021
• Θέματα: Ultrasound propagation; Trabecular bones; Speed of sound (SOS); Broadband ultrasound attenuation (BUA); Differential scattering cross section of 180°; Backscatter coefficient; 3D-printing technology; Apparent density; Material properties; Young’s modulus; Bone structure; Διάδοση υπερήχων; Δοκιδωτά οστά; Σπογγώδη οστά; Ταχύτητα ήχου; Εξασθένηση υπερήχου; Συντελεστής οπισθοσκέδασης; 3D εκτύπωση; Φαινόμενη πυκνότητα; Ιδιότητες υλικού; Μέτρο ελαστικότητας; Δομή οστού

Ultrasound is used broadly in research, such as the field of biomechanics, where osteoporosis is studied by mechanisms of interaction of ultrasound with trabecular bone. The present study concerns the influence of trabecular bone architecture and material on ultrasound characteristics, speed of sound and backscatter coefficient, using 3D-printed trabecular bone models. 3D-printing is an innovative technology used for the creation of 3D objects. Its applications concern industry, healthcare and medical industry. This technology applied to this study, because it offers the opportunity of constructing identical trabecular bone structures for each single sample in order to quantify structural degradation. The main purpose was to construct trabecular bone replicas with as much accurate structure as possible, following the same printing methods for all the specimens in order to ensure that the results and conclusions concern only the material influence on ultrasound properties. First, replicas of bovine cancellous bones, with different structures and materials, were fabricated by a 3D-printer. Polylactic acid (PLA), thermoplastic polyurethane (TPU) and polypropylene (PP) were used for the fabrication of the specimens. Then, ultrasound propagation experiments were conducted and the backscattered signals were studied in order to make conclusions about the parameters of trabecular bone replicas (material properties, structure) that influence the ultrasound propagation. The ultrasound measurements indicated that speed of sound has a perfect linear relationship with apparent density and that material properties, such as density and stiffness, influence the magnitude of the backscatter spectrum, whereas the shape of backscatter coefficient as a function of frequency depends on the bone structure. These outcomes most likely cannot be associated with the original trabecular bone; especially, in case of osteoporotic one. Nevertheless, significant conclusions are presented related to the origins of backscatter and ultrasound properties alteration due to structural degradation, which is a result of the ageing process and extent research may contribute to the formulation of osteoporosis diagnostic devices.