Tissue response to mechanical vibrations for “sonoelasticity imaging”

Parker, Kevin J.; Huang, Sung‐Rung; Musulin, R.A.; Lerner, Robert M.

doi:10.1016/0301-5629(90)90003-u

Cited by 442 publications

(263 citation statements)

References 6 publications

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“…Thus, the DENSE-MRE spectral sensitivity ⌽ DM is found by maximizing Eq. [9] with respect to the arbitrary phase offset . The solution is easily found by setting the only term containing the phase offset in Eq.…”

Section: Theorymentioning

confidence: 99%

“…The solution is easily found by setting the only term containing the phase offset in Eq. [9] to identity, i.e.,…”

Section: Theorymentioning

confidence: 99%

“…As the propagation of a monochromatic wave is modeled by the equation of propagation within a viscoelastic material, the viscoelastic properties can be obtained via assessment of the displacement. Acquiring images of propagating waves is the principle of dynamic elastography using MRI (8) or ultrasound imaging (9,10). Dynamic MRelastography (MRE) has been successfully applied, for instance, to breast (11,12), liver (13)(14)(15), and brain (16 -18).…”

mentioning

confidence: 99%

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Application of DENSE‐MR‐elastography to the human heart

Robert

Sinkus

Gennisson

et al. 2009

Magnetic Resonance in Med

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Typically, MR-elastography (MRE) encodes the propagation of monochromatic acoustic waves in the MR-phase images via sinusoidal gradients characterized by a detection frequency equal to the frequency of the mechanical vibration. Therefore, the echo time of a conventional MRE sequence is typically longer than the vibration period which is critical for heart tissue exhibiting a short T 2 . Thus, fast acquisition techniques like the so-called fractional encoding of harmonic motions were developed for cardiac applications. However, fractional encoding of harmonic motions is limited since it is two orders of magnitude less sensitive to motion than conventional MRE sequences for low-frequency vibrations. Here, a new sequence is derived from the so-called displacement encoding with stimulated echoes (DENSE) sequence. This sequence is more sensitive to displacement than fractional encoding of harmonic motions, and its spectral specificity is equivalent to conventional MRE sequences. The theoretical spectral properties of this new motion-encoding technique are validated in a phantom and excised pork heart specimen. An excellent agreement is found for the measured displacement fields using classic MRE and displacement encoding with stimulated echoes MRE (8% maximum difference). In addition, initial in vivo results on a healthy volunteer clearly show propagating shear waves at 50 Hz. Thus, displacement encoding with stimulated echoes MRE is a promising technique for motion encoding within short T 2 * materials.

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Section: Theorymentioning

confidence: 99%

“…The solution is easily found by setting the only term containing the phase offset in Eq. [9] to identity, i.e.,…”

Section: Theorymentioning

confidence: 99%

mentioning

confidence: 99%

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Application of DENSE‐MR‐elastography to the human heart

Robert

Sinkus

Gennisson

et al. 2009

Magnetic Resonance in Med

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“…Elastography or elasticity imaging has developed into an imaging modality for the diagnosis of abnormalities in the breast, prostate, thyroid, liver and kidneys, as well as for intravascular atherosclerotic plaque characterization applications (Parker et al 1990;Ophir et al 1991;O'Donnell et al 1994;Chen et al 1995;Bamber and Bush 1996;de Korte et al 2000;Pesavento et al 2000;Insana et al 2001;Nightingale et al 2001;Varghese et al 2001). Elastography also enhances the capability for imaging and monitoring thermal ablative therapies for cancer treatment in organs such as the liver, kidney and prostate that are not clearly visualized under conventional ultrasound (US) imaging (Stafford et al 1998;Righetti et al 1999;Varghese et al 2002Varghese et al , 2003Souchon et al 2003).…”

Section: Introductionmentioning

confidence: 99%

“…Elastography also enhances the capability for imaging and monitoring thermal ablative therapies for cancer treatment in organs such as the liver, kidney and prostate that are not clearly visualized under conventional ultrasound (US) imaging (Stafford et al 1998;Righetti et al 1999;Varghese et al 2002Varghese et al , 2003Souchon et al 2003). Different types of perturbation or mechanical stimuli, such as quasistatic compression (Ophir et al 1991;O'Donnell et al 1994;Hall et al 2003), dynamic vibration (Parker et al 1990;Dutt et al 2000) or acoustic radiation force (Nightingale et al 2001;Fatemi et al 2002;Lizzi et al 2003), have been used to calculate local tissue displacements or strains, revealing a profile of local stiffness changes in biologic tissue. These stiffness variations provide new information on the pathologic state of tissue, enabling its application for diagnosis of disease.…”

Section: Introductionmentioning

confidence: 99%

Improvements in elastographic contrast-to-noise ratio using spatial-angular compounding

Techavipoo¹,

Varghese²

2005

Ultrasound in Medicine & Biology

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Spatial-angular compounding is a new technique developed for improving the signal-to-noise ratio (SNR) in elastography. Under this method, elastograms of a region-of-interest (ROI) are obtained from a spatially weighted average of local strain estimated along different insonification angles. In this article, we investigate the improvements in the strain contrast and contrast-to-noise ratio (CNR) of the spatially compounded elastograms. Spatial angular compounding is also applied and evaluated in conjunction with global temporal stretching. Quantitative experimental results obtained using a single-inclusion tissue-mimicking phantom demonstrate that the strain contrast reduces slightly but the CNR improves by around 8 to 13 dB. We also present experimental spatial angular compounding results obtained from an in vitro thermal lesion in canine liver tissue embedded in a gelatin phantom that demonstrate the improved visual characteristics (due to the improved CNR) of the compound elastogram. The experimental results provide guidelines for the practical range of maximum insonification angles and estimates of the optimum angular increment.

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