Journal ArticleDOI
Improving accuracy in estimation of artery-wall displacement by referring to center frequency of RF echo
Hideyuki Hasegawa,Hiroshi Kanai +1 more
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TLDR
This error suppression was investigated through simulation experiments and in vivo experiments on the human carotid artery using a correlation estimator with quadrature demodulated complex signals.Abstract:
Noninvasive measurement of mechanical properties, such as elasticity, of the arterial wall, is useful for diagnosis of atherosclerosis. The elasticity of the arterial wall can be estimated by combining measurement of displacement of the arterial wall with that of blood pressure. In general, the displacement of the arterial wall is estimated from the phase shift of radio frequency (RF) echoes between two consecutive frames using a correlation estimator with quadrature demodulated complex signals. Recently, digitized data of broadband RF echoes are available in modern diagnostic equipment. The Fourier transform can be used to estimate the phase of the RF echo at each frequency within the RF frequency bandwidth. Therefore, the phase shifts between RF echoes of two consecutive frames can be estimated at multiple frequencies. In this estimation, due to object displacement, the RF echo is time shifted in comparison with that of the previous frame. However, the position of the time window for the Fourier transform is not changed between two consecutive frames. This change in relative position between the RF echo and the time window has a strong influence on the estimation of the artery-wall displacement, resulting in error. To suppress this error, the phase shift should be estimated at the actual RF center frequency. In this paper, this error suppression was investigated through simulation experiments and in vivo experiments on the human carotid artery.read more
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Journal ArticleDOI
An overview of elastography - an emerging branch of medical imaging.
Armen Sarvazyan,Timothy J. Hall,Matthew W. Urban,Mostafa Fatemi,Salavat R. Aglyamov,Brian S. Garra +5 more
TL;DR: This paper presents a classification of elasticity measurement and imaging techniques based on the methods used for generating a stress in the tissue, and measurement of the tissue response and presents various techniques of EI.
Journal ArticleDOI
Real-Time Regularized Ultrasound Elastography
TL;DR: This paper introduces two real-time elastography techniques based on analytic minimization (AM) of regularized cost functions that produce axial strain and integer lateral displacement, while the second method produces both axial and lateral strains.
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Material property estimation for tubes and arteries using ultrasound radiation force and analysis of propagating modes
TL;DR: The changes observed in the artery dispersion curves suggest that this methodology of exciting mechanical waves and characterizing the modes of propagation has potential for studying arterial elasticity.
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Lamb wave dispersion ultrasound vibrometry (LDUV) method for quantifying mechanical properties of viscoelastic solids
TL;DR: The results suggest that the LDUV technique can be used to quantify the mechanical properties of soft tissues with a plate-like geometry.
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Error in estimates of tissue material properties from shear wave dispersion ultrasound vibrometry
TL;DR: The accuracy of the SDUV method is reported over a range of different values of mu1 and mu2 to evaluate variation of the aforementioned parameters on the estimated shear wave velocity and material property measurements and to validate the error prediction model.
References
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