Measurement of Viscoelastic Properties of Polyacrylamide-Based Tissue-Mimicking Phantoms for Ultrasound Elastography Applications
05 Apr 2010-IEEE Transactions on Instrumentation and Measurement (IEEE)-Vol. 59, Iss: 5, pp 1224-1232
TL;DR: Polyacrylamide gel based tissue-mimicking phantoms have been developed to experimentally study the role of viscoelastic properties inPhantoms and indicate that stiffer samples exhibit large variations in the storage modulus when the precompression levels are altered.
Abstract: Many ailments and/or malfunctions of the body have been observed to change the viscous behavior and elastic properties of biological soft tissues. The technique of elastography has evolved to image such properties. The clinical evidence gathered during studies involving elastography to identify cancerous lesions is very promising. However, the quantification of the resolution and specificity of elastography is best achieved under a controlled study using tissue-mimicking phantoms. One challenge is to reproduce viscoelastic behavior in phantoms as observed in biological tissues. In this paper, polyacrylamide gel based tissue-mimicking phantoms have been developed to experimentally study the role of viscoelastic properties in a controlled manner. To measure the Young's modulus, the phantoms were subjected to linear loading, and the stress-strain relationship is deduced therefrom. It is seen that the phantoms show hysteresis behavior. The viscoelastic properties of these phantoms were measured by subjecting the samples to cyclic loading. Normal forces during this process of loading were also measured as a measure of sample elasticity. To emulate the normal and pathological lesions, samples were prepared with varying concentration of monomer and studied. Three models, namely, Maxwell, Kelvin-Voigt (KV), and Kelvin-Voigt fractional derivative (KVFD), were chosen to fit the experimental data. Of these, the KVFD model was found to be best fitting for the experimental data obtained. Results indicate that stiffer samples exhibit large variations in the storage modulus when the precompression levels are altered.
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TL;DR: Investigation of inertial cavitation inside a phantom treated by pulsed HIFU found that, when APW was 19.5W, pHIFU with short PD was much easier to form SL adjacent to the focal region inside the phantom, while it was difficult for cHIFU to generate cavitation bubbles.
19 citations
TL;DR: It is argued that the long history of biomechanics, including the concept of the extended relaxation spectrum, along with data collected from viscoelastic soft tissues over an extended range of times and frequencies, and the theoretical framework of multiple relaxation models which model the multi-scale nature of physical tissues, all lead to the conclusion that fractional derivative models represent the most succinct and meaningful models of soft tissue viscoELastic behavior.
Abstract: A rising wave of technologies and instruments are enabling more labs and clinics to make a variety of measurements related to tissue viscoelastic properties. These instruments include elastography imaging scanners, rheological shear viscometers, and a variety of calibrated stress-strain analyzers. From these many sources of disparate data, a common step in analyzing results is to fit the measurements of tissue response to some viscoelastic model. In the best scenario, this places the measurements within a theoretical framework and enables meaningful comparisons of the parameters against other types of tissues. However, there is a large set of established rheological models, even within the class of linear, causal, viscoelastic solid models, so which of these should be chosen? Is it simply a matter of best fit to a minimum mean squared error of the model to several data points? We argue that the long history of biomechanics, including the concept of the extended relaxation spectrum, along with data collected from viscoelastic soft tissues over an extended range of times and frequencies, and the theoretical framework of multiple relaxation models which model the multi-scale nature of physical tissues, all lead to the conclusion that fractional derivative models represent the most succinct and meaningful models of soft tissue viscoelastic behavior. These arguments are presented with the goal of clarifying some distinctions between, and consequences of, some of the most commonly used models, and with the longer term goal of reaching a consensus among different sub-fields in acoustics, biomechanics, and elastography that have common interests in comparing tissue measurements.
17 citations
Cites methods or result from "Measurement of Viscoelastic Propert..."
...For some phantoms (Sinkus et al., 2007; Kumar et al., 2010; Coussot et al., 2009) and...
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...For some phantoms (Sinkus et al 2007, Coussot et al 2009, Kumar et al 2010) and for the QIBA phantom studies (Rouze et al 2018), the fractional Kelvin– Voigt model is suitable....
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...Kumar et al (2010) in their study of Maxwell, Kelvin–Voigt, and fractional Kelvin–Voigt models applied to measurements of Young’s modulus from polyacrylamide-based phantoms found that only the fractional KV model matched their data....
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TL;DR: A pilot study to investigate the performance of ultrasound stiffness imaging methods namely Ultrasound Elastography Imaging (UEI) and Acoustic Radiation Force Impulse (ARFI) Imaging indicates that both ARFI and UEI represent the abnormalities better than conventional US B mode imaging whereas UEI enhances the underlying modulus contrast into improved strain contrast.
14 citations
TL;DR: A unique PAM method that combined the robust Capon beamformer (RCB) with the sign coherence factor (SCF) was proposed to monitor the superficial vessel erosion in real time and showed that the proposed PAM could be improved by 22.5±3.2dB compared with TEA and RCB-based PAM.
13 citations
16 Jul 2012
TL;DR: This paper deals with the preparation and study of agar based tissue mimicking phantoms and Reproducible phantom preparation procedures for matching various properties of normal and abnormal human soft tissues.
Abstract: Tissue mimicking phantoms play a crucial role in the development of Acoustic Radiation Force Impulse Imaging. This paper deals with the preparation and study of agar based tissue mimicking phantoms. Acoustic and elastic properties are studied for various concentration of agar samples (1.7%–10% by weight). Acoustic properties are measured using pulse echo transmit receive principle. Young's modulus of the samples are measured using compression test. Reproducible phantom preparation procedures are standardised for matching various properties of normal and abnormal human soft tissues.
9 citations
Cites background from "Measurement of Viscoelastic Propert..."
...Both types of phantoms are developed for UE applications and their acoustic and elastic properties are characterised by many groups [7], [8], [9]....
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"Measurement of Viscoelastic Propert..." refers methods in this paper
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TL;DR: A balanced mechanics-materials approach and coverage of the latest developments in biomaterials and electronic materials, the new edition of this popular text is the most thorough and modern book available for upper-level undergraduate courses on the mechanical behavior of materials as discussed by the authors.
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