A method to identify acoustic reverberation in multilayered homogeneous media

Duarte, Marcelo A.; Machado, João Carlos; Pereira, Wagner Coelho de Albuquerque

doi:10.1016/j.ultras.2003.12.043

Cited by 13 publications

(11 citation statements)

References 20 publications

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“…However, even if a proper multiple suppression is not possible because of unknown filter parameters, imaging of the primary echo signals of the first inner structure is applicable, while subsequent signal parts are suppressed. The approach which is used on each single a-line of the surface-echo-suppressed signals S F [see (16)] is based on a convolution model s t wt et F ( ) = ( ) ( ).…”

Section: ) Predictive Deconvolutionmentioning

confidence: 99%

“…In literature, most of the existing approaches use an acoustic wave propagation model in layered media to achieve a proper suppression of reverberations [14]- [19]. Thereby, reverberations induced by multilayered media were classified by a comparison of their power spectra and linear combination of their temporal relationship with respect to time of flight (ToF) [16], [19]. Predictive deconvolution is another approach, initially utilized in seismic exploration, which also exploits ideal wave propagation by counting on the repeatability character of reverberations [15], [17], [20].…”

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confidence: 99%

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Ultrasonic imaging of complex specimens by processing multiple incident angles in full-angle synthetic aperture focusing technique

Scharrer

Schrapp

Rupitsch

et al. 2014

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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In the evaluation of large-scale metallic specimens, X-ray CT suffers from limited penetration, which results in artifacts in the reconstructed image. Data fusion of information obtained by different modalities allows correction of those artifacts. In this contribution, an approach is presented to provide complementary data of the inner pattern of the specimen by ultrasonic testing in immersion mode. To process an ultrasonic imaging full-angle synthetic aperture focusing technique, data are acquired along the a priori known contour of the specimen. Substantial discrepancies in speed of sound between the couplant and the material of the specimen lead to refraction effects which are corrected by a virtual source element method. Furthermore, several incident angles at each virtual source are utilized to achieve an enhanced detectability of inner structural edges. However, arising reverberations limit image quality and must be suppressed by predictive deconvolution. Additionally, a subspace analysis and projection method is utilized to remove echoes of the a priori known surface in the reconstructed image which potentially mask information of near-surface structures. In comparison with exclusively perpendicular insonification, resulting images show a significant enhanced possibility of detection for inner structural edges even in adverse orientations for ultrasonic imaging. Furthermore, surface echoes and reverberations are suppressed by the proposed filter methods in a reliable way.

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Section: ) Predictive Deconvolutionmentioning

confidence: 99%

mentioning

confidence: 99%

Ultrasonic imaging of complex specimens by processing multiple incident angles in full-angle synthetic aperture focusing technique

Scharrer

Schrapp

Rupitsch

et al. 2014

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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“…Stationary clutter rejection methods have been developed mostly for color Doppler flow imaging (Bjaerum et al, 2002;Cloutier et al, 2003;Yoo et al, 2003). For identifying reverberations in normal ultrasound images, Duarte et al (2003) presented an algorithm based on the comparison of power spectra and time-of-flight. Bylund et al (2005) proposed to detect reverberation artifacts from a static reflector using quadrature filters.…”

Section: Related Workmentioning

confidence: 99%

Probabilistic framework for tracking in artifact-prone 3D echocardiograms

Leung

Danilouchkine

Stralen

et al. 2010

Medical Image Analysis

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“…This method also assumes, although implicitly, an ideal propagation model by relying on the repeatability of reverberating patterns. The methods presented in [5,6] deal with the identification of reverberation echoes in multilayered media based on time-of-flight analysis of all possible echoes and their power spectrum comparison. In addition to the ideal propagation models mentioned above, these techniques assume nonoverlapping echo patterns amenable to time-of-flight analysis, which requires the thickness of each layer to be relatively large compared to the echo wavelength.…”

Section: Introductionmentioning

confidence: 99%

Ultrasonic Flaw Detection and Imaging through Reverberant Layers via Subspace Analysis and Projection

Demirli

Amin

Shen

et al. 2012

Advances in Acoustics and Vibration

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Ultrasonic flaw detection and imaging through reverberant layers are challenging problems owing to the layer-induced reverberations and front surface reflections. These undesired signals present a strong clutter and mask the flaw echoes. In this paper, a subspace-based approach is developed for removing, or significantly reducing, the unwanted reverberations, enabling proper flaw detection and imaging. The technique utilizes a set of independent clutter-only reference measurements of the material through the layer. If these measurements are not available, array measurements of the material with flaws are used instead. The clutter, due to its high strength relative to the flaw reflections, forms a subspace spanned by the eigenvectors corresponding to the dominant eigenvalues of the data covariance matrix. The clutter subspace is estimated and removed using orthogonal subspace projection. The clutter usually occupies multidimension subspace that is dependent on the level of coupling, material inhomogeneity, surface roughness, and the sampling rate of the measurements. When the clutter-only reference is not available, information theoretic techniques are used to estimate the dimension of the clutter subspace so that clutter signals are sufficiently suppressed without distorting the flaw signals. The effectiveness of the proposed approach is demonstrated using simulations and real measurement results.

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A method to identify acoustic reverberation in multilayered homogeneous media

Cited by 13 publications

References 20 publications

Ultrasonic imaging of complex specimens by processing multiple incident angles in full-angle synthetic aperture focusing technique

Ultrasonic imaging of complex specimens by processing multiple incident angles in full-angle synthetic aperture focusing technique

Probabilistic framework for tracking in artifact-prone 3D echocardiograms

Ultrasonic Flaw Detection and Imaging through Reverberant Layers via Subspace Analysis and Projection

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