Journal ArticleDOI
Mean‐scatterer spacing estimates with spectral correlation
Tomy Varghese,Kevin D. Donohue +1 more
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TLDR
This paper addresses the problem of estimating mean-scatterer spacing from the backscattered ultrasound signal using spectral redundancy characterized by the spectral autocorrelation (SAC) function, and results indicate that SAC- based estimates converge more reliably over smaller amounts of data than cepstrum-based estimates.Abstract:
An ultrasonic backscattered signal from material comprised of quasiperiodic scatterers exhibit redundancy over both its phase and magnitude spectra. This paper addresses the problem of estimating mean‐scatterer spacing from the backscattered ultrasound signal using spectral redundancy characterized by the spectral autocorrelation (SAC) function. Mean‐scatterer spacing estimates are compared for techniques that use the cepstrum and the SAC function. A‐scan models consist of a collection of regular scatterers with Gamma distributed spacings embedded in diffuse scatterers with uniform distributed spacings. The model accounts for attenuation by convolving the frequency dependent scattering centers with a time‐varying system response. Simulation results indicate that SAC‐based estimates converge more reliably over smaller amounts of data than cepstrum‐based estimates. A major reason for the performance advantage is the use of phase information by the SAC function, while the cepstrum uses a phaseless power spec...read more
Citations
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Journal ArticleDOI
Cyclostationarity: half a century of research
TL;DR: A concise survey of the literature on cyclostationarity is presented and includes an extensive bibliography and applications of cyclostatedarity in communications, signal processing, and many other research areas are considered.
Journal ArticleDOI
Elastography: ultrasonic estimation and imaging of the elastic properties of tissues.
Jonathan Ophir,S.K. Alam,Brian S. Garra,Faouzi Kallel,Elisa E. Konofagou,Thomas A. Krouskop,Tomy Varghese +6 more
TL;DR: The strain filter formalism and its utility in understanding the noise performance of the elastographic process is given, as well as its use for various image improvements.
Journal ArticleDOI
Bibliography on cyclostationarity
TL;DR: The present bibliography represents a comprehensive list of references on cyclostationarity and its applications by listing most of the existing references up to the year 2005 and by providing a detailed classification group.
Journal ArticleDOI
Reduction of signal decorrelation from mechanical compression of tissues by temporal stretching: applications to elastography.
S. Kaisar Alam,Jonathan Ophir +1 more
TL;DR: The theory predicts that if the postcompression echo signals are stretched before the TDE step, then for small strains, the cross-correlation function very closely resembles the autocorrelation function, and correlation is improved if temporal stretching is applied.
Journal ArticleDOI
Direct strain estimation in elastography using spectral cross-correlation.
TL;DR: Spectral cross-correlation is shown to be more sensitive to small shifts in the power spectrum and, thus, provides better estimation for smaller strains when compared to the spectral centroid shift.
References
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