Spatially variant regularization of lateral displacement measurement using variance

Sumi, Chikayoshi; Itoh, Toshiki

doi:10.1016/j.ultras.2008.10.019

Cited by 3 publications

(6 citation statements)

References 45 publications

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“…In this chapter, although we applied regularization only to the shear modulus reconstruction (Method F: Sumi, 2005d), its application to the displacement vector measurement, i.e., displacement component-dependent regularization or directionaldependent regularization (Sumi & Sato, 2008c;Sumi & Itoh, 2009b) will also be effective in stabilizing the strain tensor measurements by MAM, MDM, and MCSPGM in addition to shear modulus reconstruction. In both regularizations, the measured or theoretically predicted strain tensor variances are used to set the regularization parameters (Sumi & Sato, 2008c;Sumi, 2007aSumi & Itoh, 2009b.…”

Section: Discussionmentioning

confidence: 99%

“…In both regularizations, the measured or theoretically predicted strain tensor variances are used to set the regularization parameters (Sumi & Sato, 2008c;Sumi, 2007aSumi & Itoh, 2009b. With such regularizations, a spatially varying regularization is also realized.…”

Section: Discussionmentioning

confidence: 99%

“…However, reports of actual shear modulus reconstruction using measured strain tensor distributions are few with the exception of our reports (e.g., Sumi, 2007aSumi, , 2008aSumi & Sato, 2008c;Sumi & Itoh, 2010e using the regularizations for strain measurement or shear modulus reconstrcution; Sumi, 2008a;Sumi et al, 2008f, 2008i using LM) and the reconstruction using a measured axial displacement distribution (e.g., Doyley et al, 2005 using another regularization for Young modulus). Specifically, we reported 2D direct shear modulus reconstruction using regularized strain tensor measurement (Sumi & Sato, 2008c;Sumi & Itoh, 2009b) as well as regularized direct 1D shear modulus reconstruction (Sumi, 2008e;Sumi & Itoh, 2010e;Sumi, 2007a) using raw strain tensor measurement. These reconstructions were stably performed for agar phantoms by using our developed regularization, i.e., spatially variant regularization being dependent of the accuracies at each position of the measured strain tensor components.…”

Section: Phase Matchingmentioning

confidence: 99%

“…These reconstructions were stably performed for agar phantoms by using our developed regularization, i.e., spatially variant regularization being dependent of the accuracies at each position of the measured strain tensor components. Because the measurement accuracy depends on the direction of the displacement, according to the accuracies of the respective displacements, they are also properly regularized, i.e., referred to as displacement componentdependent regularization or directional-dependent regularization (Sumi & Sato, 2008c;Sumi & Itoh, 2009b). As briefly reviewed in section 1, various 1D reconstructions using the axial strain were also obtained by Sumi for human in vivo tissues when the targets become deformed in the axial and lateral directions, respectively.…”

Section: Phase Matchingmentioning

confidence: 99%

“…Moreover, when the target deforms in the lateral direction, the 1D reconstruction further decreases the accuracy in reconstrcution (Sumi, 2007f). Moreover, for the 2D reconstruction, the use of only the regularizations still yields an inaccurate reconstruction (Sumi & Sato, 2008c;Sumi & Itoh, 2009b). Thus, LM was also used later (Sumi, 2008a;Sumi et al, 2008f, 2008i).…”

Section: Phase Matchingmentioning

confidence: 99%

See 4 more Smart Citations

Ultrasonic Measurement and Imaging with Lateral Modulation – Echo, Tissue Motion and Elasticity

Sumi¹

2011

Ultrasound Imaging

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Phase Matchingmentioning

confidence: 99%

Section: Phase Matchingmentioning

confidence: 99%

Section: Phase Matchingmentioning

confidence: 99%

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Ultrasonic Measurement and Imaging with Lateral Modulation – Echo, Tissue Motion and Elasticity

Sumi¹

2011

Ultrasound Imaging

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Lateral and shear strain imaging for ultrasound elastography

Varghese¹

2020

Tissue Elasticity Imaging

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Ultrasonic lateral modulation imaging, speckle reduction, and displacement vector measurements using simple single-beam scanning or plural crossed-beam scanning with new spectra frequency division processing methods

Sumi¹,

Yousuke²

2012

RMI

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The development of effective ultrasonic tissue displacement measurement methods increases the number of possible applications for various tissue displacement and strain measurements. These applications include measurements of spontaneous motions/deformations generated by heart motion; pulsations from phenomena such as blood flow (intracardiac, intravascular, and carotid); heart, blood vessel, and liver motion; and motion from artificial sources such as motions/deformations generated by applying static compression/stretching forces, vibration or acoustic radiation forces (breast and liver). For arbitrary orthogonal coordinate systems obtained using arbitrary transducer types (eg, linear, convex, sector, arc, or radial array types, or single aperture types with a mechanical scan), several lateral modulation (LM) methods (eg, scanning with plural crossed or steered beams over a region of interest) have been developed that can be used with new echo imaging methods for tissue displacement/ deformation measurements. Specifically, by using such beamforming methods, in addition to highly accurate displacement vector and lateral displacement measurements, LM echo imaging with a high lateral carrier frequency and a high lateral resolution has been developed. Another new beamforming method, referred to as "a steering angle (ASTA) method," ie, scanning with a defined steering angle, is also described. In addition to conventional non-steered-beam scanning (ie, a version of ASTA) and conventional steered-beam scanning with a variable steering angle (eg, sector, arc, radial scan), a simple, single-beam scanning method also permits the use of LM, which yields an accurate displacement vector measurement with fewer calculations than the original LM methods. This is accomplished by using a previously developed spectra frequency division method (SFDM). However, the lateral carrier frequency and the measurement accuracy acquired by using such a single-beam scanning method are lower than those achieved with the original LM scanning methods and should be increased (ie, by using a quasi-LM method). In this report, the effectiveness of the use of the new SFDMs is verified with experiments on agar phantoms, in which conventional non-steered, focused single-beam transmission/reception scanning is performed together with high-speed non-steered single plane-wave transmission and non-steered, focused single-beam reception scanning using a linear array-type transducer. For comparison, the original LMs, with their respective transmissions of crossed, steered focused beams and plane waves are also performed. Because the use of rectangular apodization functions (ie, no apodization) yields a larger bandwidth in a lateral direction than the effective use of parabolic functions with the original LM method, it is shown that disregarding the lateral low-frequency spectra yields useful quasi-LM echo imaging with a high lateral frequency, and Dovepress submit your manuscript | www.dovepress.com Reports in Medical Imaging 2012:5 further significantly inc...

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Spatially variant regularization of lateral displacement measurement using variance

Cited by 3 publications

References 45 publications

Ultrasonic Measurement and Imaging with Lateral Modulation – Echo, Tissue Motion and Elasticity

Ultrasonic Measurement and Imaging with Lateral Modulation – Echo, Tissue Motion and Elasticity

Lateral and shear strain imaging for ultrasound elastography

Ultrasonic lateral modulation imaging, speckle reduction, and displacement vector measurements using simple single-beam scanning or plural crossed-beam scanning with new spectra frequency division processing methods

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