Journal ArticleDOI
Theoretical bounds on strain estimation in elastography
TLDR
An expression for the lower bound for the strain estimation error (LBSE) is obtained, derived under the assumption that the post-compression echo signal can be reconstructed to the original shape of the echo signal before compression.Abstract:
Elastography is a technique for the estimation of tissue elasticity that is based on the estimation of strain. Tissue strain can be estimated by finite difference computations of echo time-delay. Echo time-delays are obtained by cross-correlation processing of pre- and post-compression echo signals. Errors in strain estimation can be expressed in terms of the errors in time delay estimation for given echo-signal characteristics. The smallest time delay estimation error is given by the Cramer-Rao Lower Bound (CRLB), which can be achieved when operating under the small error condition. Based on the CRLB, we obtain an expression for the lower bound for the strain estimation error (LBSE). The LBSE equation is derived under the assumption that the post-compression echo signal can be reconstructed to the original shape of the echo signal before compression. The theoretical bound given by the LBSE may or may not be achievable in practice, depending on the compliance with the requirements for echo signal reconstruction. In an example, the obtained LBSE shows that there is potential for significant reduction of the current level of noise in elastograms. >read more
Citations
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Journal ArticleDOI
Acoustic radiation force impulse imaging: in vivo demonstration of clinical feasibility.
TL;DR: Experimental results are presented demonstrating that displacements on the order of 10 microm can be generated and detected in soft tissues in vivo using a single transducer on a modified diagnostic US scanner and support the clinical feasibility of a radiation force-based remote palpation imaging system.
Journal ArticleDOI
A least-squares strain estimator for elastography
Faouzi Kallel,Jonathan Ophir +1 more
TL;DR: It is demonstrated that the LSQSE results in an increase of the elastographic sensitivity (smallest strain that could be detected), thereby increasing the strain dynamic range and reducing the strain contrast and spatial resolution.
Journal ArticleDOI
Speckle tracking methods for ultrasonic elasticity imaging using short-time correlation
TL;DR: The results demonstrate that high resolution, high SNR strain estimates can be computed using small correlation kernels (on the order of the autocorrelation width of the ultrasound signal) and correlation filtering.
Journal ArticleDOI
A theoretical framework for performance characterization of elastography: the strain filter
Tomy Varghese,Jonathan Ophir +1 more
TL;DR: A theoretical framework for performance characterization in strain estimation is presented, which includes the effect of signal decorrelation, quantization errors due to the finite temporal sampling rate, and electronic noise, which is obtained from a strain filter constructed using these limits.
Journal ArticleDOI
Elastography: Ultrasonic imaging of tissue strain and elastic modulus in vivo
TL;DR: A literature review of a variety of methods for the estimation of tissue elasticity that have been reported in the literature in the past 15 years, and of data on the elastic properties of soft tissues.
References
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Journal ArticleDOI
Elastography: A Quantitative Method for Imaging the Elasticity of Biological Tissues
TL;DR: Initial results of several phantom and excised animal tissue experiments are reported which demonstrate the ability of this technique to quantitatively image strain and elastic modulus distributions with good resolution, sensitivity and with diminished speckle.
Book
Detection of signals in noise
Robert N. McDonough,A. D. Whalen +1 more
TL;DR: In underwater sonar systems, external acoustic noise is generated by waves and wind on the water surface, by biological agents (fish, prawns, etc.), and by man-made sources such as engine noise.
Journal ArticleDOI
Internal displacement and strain imaging using ultrasonic speckle tracking
TL;DR: In this paper, the authors extended the ultrasound speckle tracking method to allow measurement of internal displacement and strain fields over a wide dynamic range of tissue motion, which should lead to enhanced contrast resolution in strain and elasticity images.
Journal ArticleDOI
“Sonoelasticity” images derived from ultrasound signals in mechanically vibrated tissues
TL;DR: Preliminary experiments indicate that these novel images may be useful for detecting hard tumors in the prostate, liver, breast, and other organs.
Journal ArticleDOI
Algorithms for ambiguity function processing
TL;DR: The nature of the ambiguity processing is interpreted, and an algorithm approach is shown that minimizes the processing burden over a broad category of applications without affecting performance.
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