Measurement of the Dispersion and Attenuation of Cylindrical Ultrasonic Guided Waves in Long Bone

Low-frequency axial ultrasound velocity correlates with bone mineral density and cortical thickness in the radius and tibia in pre- and postmenopausal women

“…Moreover, the good sensitivity to cortical thickness of LF ultrasound was confirmed by the corresponding correlation coefficient. It has recently been argued that FAS could not be as sensitive to endosteal bone properties and cortical thickness as guided waves consistent with Lamb modes [40]. Although this is partly true, FAS, however, is also essentially a guided wave and, as shown by the present study, provides considerable sensitivity to endosteal bone property changes with aging when the wavelength is sufficiently long.…”

A free plate model can predict guided modes propagating in tubular bone-mimicking phantoms

“…[3][4][5] Accuracy of estimates for bone characteristics depends on the chosen model for ultrasound propagation in the cortical bone (which represents the "forward problem") and on its ability to account for the complexity of the waveguide, including not only the elastic anisotropy, the tubular shape of bone and the presence of soft tissues, but also a variable thickness, irregular geometry, inhomogeneity, and absorption, for example. In previous investigations, more or less complex waveguide models, such as free plate 5 and tube models, 3,4,11 or bilayer models, [12][13][14] were applied and found to conform fairly well to experimental dispersion curves of guided modes in bone mimicking phantoms 3,5,12,14 and in ex vivo bone specimens. [3][4][5]13 On the other hand, more complex models involving more physical parameters would make the solution of the inverse problem more difficult to find.…”

Excitation of ultrasonic Lamb waves using a phased array system with two array probes: Phantom and in vitro bone studies

“…Q3 asound 19 Phased array 20 Beam steering 21 Osteoporosis 22 Cortical bone 23 2 4 a b s t r a c t 25 Long bones are good waveguides to support the propagation of ultrasonic guided waves. The low-order 26 guided waves have been consistently observed in quantitative ultrasound bone studies.…”