Low-frequency ultrasonic velocity measurements in human calcaneal trabecular bone
| Autor: | R. Strelitzki, P H F Nicholson, J A Evans |
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| Rok vydání: | 1997 |
| Předmět: |
Adult
Male Materials science Physiology Wave propagation Bar (music) Biomedical Engineering Biophysics Context (language use) Low frequency Optics Bone Density Physiology (medical) Humans Aged Ultrasonography Aged 80 and over business.industry Ultrasound Middle Aged Biomechanical Phenomena Bone Diseases Metabolic Calcaneus Wavelength Osteoporosis Female Ultrasonic sensor business Biomedical engineering |
| Zdroj: | Physiological Measurement. 18:119-127 |
| ISSN: | 1361-6579 0967-3334 |
| DOI: | 10.1088/0967-3334/18/2/003 |
| Popis: | Ultrasonic velocities were measured in three orthogonal directions for 17 cubes ( approximately) of defatted calcaneal trabecular bone using a novel pulse transmission method with 37 kHz transducers. Since the wavelength was greater than the cross-sectional dimensions of the specimens, it was assumed that bar wave propagation was occurring and this allowed Young's modulus to be derived from velocity and apparent density. Velocity varied from in axis 1 (proximo-distal) to in axis 3 (medio-lateral). Thus, the velocities measured in axis 3 were considerably lower than those typically seen in clinical measurements of the calcaneus. The derived Young's moduli ranged from (axis 1) to (axis 3), and were comparable in magnitude to some previously published data from mechanical testing. The results suggest that velocities measured with this technique do indeed correspond to bar velocities, and consequently that low-frequency ultrasound can be used to directly predict the mechanical properties of trabecular bone specimens in vitro. On the other hand, given the marked differences in geometry, wavelengths used and the presence of fat, it raises questions about the validity of applying the bar wave equation in the context of higher-frequency velocity measurements in the intact calcaneus in vivo, despite the fact that this has been found to be useful by a number of previous workers. This may require a review of the clinical implications of high-frequency ultrasound data. Keywords: ultrasound, low frequency, trabecular bone, calcaneus, mechanical properties |
| Databáze: | OpenAIRE |
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