In the study of the mechanical behavior of biological tissues, many complex
tissues are often modeled as poroelastic systems due to their high fluid content and
mobility. Fluid content and fluid transport mechanisms in tissues are known to be highly
correlated with several pathologies. Thus, imaging techniques capable of providing
accurate information about these mechanisms can potentially be of great diagnostic
value.
Ultrasound elastography is an imaging modality that is currently used as a
complement to sonographic methods to detect a variety of tissue pathologies.
Poroelastography is a new elastographic technique that has been recently proposed to
image the mechanical behavior of tissues that can be modeled as poroelastic media. The
few poroelastographic studies retrievable focus primarily on homogeneous poroelastic
media. In this study, a statistical analysis of the performance of poroelastographic
techniques in a non-homogeneous poroelastic simulation model under different loading
conditions was carried out. The two loading conditions simulated were stress relaxation
(application of constant strain) and creep compression (application of constant stress),
both of which have been commonly used in the field of poroelastography. Simulations were performed using a FE poroelastic simulation software combined with ultrasound
simulation software techniques and poroelastography processing algorithms developed
in our laboratory. The non-homogeneous poroelastic medium was modeled as a cube
(background) containing a cylindrical inclusion (target). Different permeability, Young’s
modulus and Poisson’s ratio contrasts between the underlying matrix of the background
and the target were considered. Both stress relaxation and creep compression loading
conditions were simulated. The performance of poroelastography techniques was
quantified in terms of accuracy, elastographic contrast–to–noise ratio and contrast
transfer efficiency.
The results of this study show that, in general, image quality of both axial strain
and effective Poisson’s ratio poroelastograms is a complex function of time, which
depends on the contrast between the poroelastic material properties of the background
and the poroelastic material properties of the target and the boundary conditions. The
results of this study could have important implications in defining the clinical range of
applications of poroelastographic techniques and in the methodologies currently
deployed.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/ETD-TAMU-2010-12-8762 |
| Date | 2010 December 1900 |
| Creators | Chaudhry, Anuj |
| Contributors | Righetti, Raffaella |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | thesis, text |
| Format | application/pdf |
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