scholarly journals The effect of trabecular material properties on the frequency dependence of backscatter from cancellous bone (L)

2003 ◽  
Vol 114 (1) ◽  
pp. 62-65 ◽  
Author(s):  
Keith A. Wear
Keyword(s):  
Frequency Dependence ◽  
Cancellous Bone ◽  
Material Properties

Material properties of femoral cancellous bone in axial loading

1980 ◽  
Vol 97 (2) ◽  
pp. 95-102 ◽  
Author(s):  
Antonius Rohlmann ◽  
Hans Zilch ◽  
Georg Bergmann ◽  
Reinhard Kolbel
Keyword(s):  
Cancellous Bone ◽  
Material Properties ◽  
Axial Loading

Analysis of frequency dependence of ultrasonic backscatter coefficient in cancellous bone

2008 ◽  
Vol 124 (6) ◽  
pp. 4083-4090 ◽  
Author(s):  
Dean Ta ◽  
Weiqi Wang ◽  
Kai Huang ◽  
Yuanyuan Wang ◽  
Lawrence H. Le
Keyword(s):  
Frequency Dependence ◽  
Cancellous Bone ◽  
Backscatter Coefficient ◽  
Ultrasonic Backscatter

scholarly journals Transversely Isotropic Elasticity Imaging of Cancellous Bone

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
Spencer W. Shore ◽  
Paul E. Barbone ◽  
Assad A. Oberai ◽  
Elise F. Morgan
Keyword(s):  
Mechanical Properties ◽  
Inverse Problem ◽  
Cancellous Bone ◽  
Material Properties ◽  
Transversely Isotropic ◽  
Elasticity Imaging ◽  
Elastic Parameters ◽  
Displacement Fields ◽  
Isotropic Materials ◽  
Isotropic Elasticity

To measure spatial variations in mechanical properties of biological materials, prior studies have typically performed mechanical tests on excised specimens of tissue. Less invasive measurements, however, are preferable in many applications, such as patient-specific modeling, disease diagnosis, and tracking of age- or damage-related degradation of mechanical properties. Elasticity imaging (elastography) is a nondestructive imaging method in which the distribution of elastic properties throughout a specimen can be reconstructed from measured strain or displacement fields. To date, most work in elasticity imaging has concerned incompressible, isotropic materials. This study presents an extension of elasticity imaging to three-dimensional, compressible, transversely isotropic materials. The formulation and solution of an inverse problem for an anisotropic tissue subjected to a combination of quasi-static loads is described, and an optimization and regularization strategy that indirectly obtains the solution to the inverse problem is presented. Several applications of transversely isotropic elasticity imaging to cancellous bone from the human vertebra are then considered. The feasibility of using isotropic elasticity imaging to obtain meaningful reconstructions of the distribution of material properties for vertebral cancellous bone from experiment is established. However, using simulation, it is shown that an isotropic reconstruction is not appropriate for anisotropic materials. It is further shown that the transversely isotropic method identifies a solution that predicts the measured displacements, reveals regions of low stiffness, and recovers all five elastic parameters with approximately 10% error. The recovery of a given elastic parameter is found to require the presence of its corresponding strain (e.g., a deformation that generates ɛ12 is necessary to reconstruct C1212), and the application of regularization is shown to improve accuracy. Finally, the effects of noise on reconstruction quality is demonstrated and a signal-to-noise ratio (SNR) of 40dB is identified as a reasonable threshold for obtaining accurate reconstructions from experimental data. This study demonstrates that given an appropriate set of displacement fields, level of regularization, and signal strength, the transversely isotropic method can recover the relative magnitudes of all five elastic parameters without an independent measurement of stress. The quality of the reconstructions improves with increasing contrast, magnitude of deformation, and asymmetry in the distributions of material properties, indicating that elasticity imaging of cancellous bone could be a useful tool in laboratory studies to monitor the progression of damage and disease in this tissue.

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