The influence of porosity and pore size on the ultrasonic properties of bone investigated using a phantom material

Ultrasonic propagation in bone has been investigated using the Leeds Ultrasonic Bone Phantom Material. Phantoms were produced with different porosities in the range of 45−83% and pore sizes of 1.3 and 0.6 mm. The phase velocity at 600 kHz was found to follow a second-order polynomial as a function of porosity. Phase velocity values between 1545 and 2211 m s−1 were measured and found to be largely independent of pore size for a given porosity. The slope of the phase velocity as a function of frequency (dispersion) decreases with increasing porosity. The values obtained from samples having different pore sizes were also similiar. The attenuation coefficient and normalized broadband ultrasonic attenuation (nBUA) reached a maximum at about 50%. The normalized attenuation ranged from 6 to 25 dB cm−1 over the porosity range available and consistently showed higher values for the larger pore size. Similarly, the nBUA values were found to be between 14 and 53 dB MHz−1 cm−1, with the values for the larger pore size being roughly 10 dB MHz−1 cm−1 greater than those for the smaller pore size. These findings demonstrate that the Leeds phantom can be used to investigate the effect of structural changes in bone and to aid the understanding of quantitative ultrasound. The results support the assumption that the velocity in trabecular bone is not dependent on pore size but is influenced by the mechanical properties of the bone's constituents and the overall framework, whereas the attenuation and BUA are also influenced by structure.

[1]  A. J. Clarke,et al.  The measurement of the velocity of ultrasound in fixed trabecular bone using broadband pulses and single-frequency tone bursts. , 1996, Physics in medicine and biology.

[2]  Acoustic and dynamic properties of two-phase media with non-spherical inclusions , 1995 .

[3]  C. Langton,et al.  P29. Dependence of ultrasonic and mechanical properties of vertebral bone on orientation , 1994 .

[4]  A. R. Gregory,et al.  ELASTIC WAVE VELOCITIES IN HETEROGENEOUS AND POROUS MEDIA , 1956 .

[5]  G Van der Perre,et al.  A comparison of time-domain and frequency-domain approaches to ultrasonic velocity measurement in trabecular bone. , 1996, Physics in medicine and biology.

[6]  P. Antich,et al.  Measurement of intrinsic bone quality in vivo by reflection ultrasound: Correction of impaired quality with slow‐release sodium fluoride and calcium citrate , 1993, Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research.

[7]  R. Strelitzki,et al.  Ultrasonic measurement: An evaluation of three heel bone scanners compared with a bench-top system , 2005, Osteoporosis International.

[8]  S. Cowin,et al.  On the dependence of the elasticity and strength of cancellous bone on apparent density. , 1988, Journal of biomechanics.

[9]  J. Medige,et al.  Ultrasound velocity and broadband attenuation over a wide range of bone mineral density , 2005, Osteoporosis International.

[10]  Jean E. Aaron,et al.  An automated method for the analysis of bone structure , 1992 .

[11]  A. Karellas,et al.  Ultrasound attenuation of the Os calcis in women with osteoporosis and hip fractures , 1988, Calcified Tissue International.

[12]  J. Barger,et al.  Acoustical properties of the human skull. , 1978, The Journal of the Acoustical Society of America.

[13]  C. Turner,et al.  Calcaneal ultrasonic measurements discriminate hip fracture independently of bone mass , 1995, Osteoporosis International.

[14]  J. A. Evans,et al.  Bone ultrasonic attenuation in women: reproducibility, normal variation and comparison with photon absorptiometry. , 1992, Clinical physics and physiological measurement : an official journal of the Hospital Physicists' Association, Deutsche Gesellschaft fur Medizinische Physik and the European Federation of Organisations for Medical Physics.

[15]  J. Currey,et al.  The Effect of Variation in Structure on the Young's Modulus of Cancellous Bone: A Comparison of Human and Non-Human Material , 1990, Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine.

[16]  Martin Greenspan,et al.  Tables of the Speed of Sound in Water , 1959 .

[17]  C. Langton,et al.  The measurement of broadband ultrasonic attenuation in cancellous bone. , 1984, Engineering in medicine.

[18]  J. A. Evans,et al.  Ultrasonic attenuation and velocity in bone. , 1990, Physics in medicine and biology.

[19]  Matthew O'Donnell,et al.  General relationships between ultrasonic attenuation and dispersion , 1978 .

[20]  G. Blake,et al.  Measurements of broadband ultrasonic attenuation in the calcaneus in premenopausal and postmenopausal women , 1992, Osteoporosis International.

[21]  P. Nicholson,et al.  The dependence of ultrasonic properties on orientation in human vertebral bone. , 1994, Physics in medicine and biology.

[22]  J Y Rho,et al.  The nonlinear transition period of broadband ultrasound attenuation as bone density varies. , 1996, Journal of biomechanics.

[23]  C M Langton,et al.  A contact method for the assessment of ultrasonic velocity and broadband attenuation in cortical and cancellous bone. , 1990, Clinical physics and physiological measurement : an official journal of the Hospital Physicists' Association, Deutsche Gesellschaft fur Medizinische Physik and the European Federation of Organisations for Medical Physics.

[24]  J. A. Evans,et al.  The effect of bone structure on ultrasonic attenuation and velocity. , 1992, Ultrasonics.

[25]  S. Goldstein,et al.  Three quantitative ultrasound parameters reflect bone structure , 1994, Calcified Tissue International.

[26]  J G Truscott,et al.  A phantom for quantitative ultrasound of trabecular bone. , 1994, Physics in medicine and biology.