scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Shear wave elasticity imaging: a new ultrasonic technology of medical diagnostics

01 Dec 1998-Ultrasound in Medicine and Biology (Elsevier)-Vol. 24, Iss: 9, pp 1419-1435
TL;DR: A physical and mathematical basis of SWEI is presented and some experimental results of pilot studies proving feasibility of this new ultrasonic technology are presented, including a theoretical model of shear oscillations in soft biological tissue remotely induced by the radiation force of focused ultrasound.
Abstract: Shear wave elasticity imaging (SWEI) is a new approach to imaging and characterizing tissue structures based on the use of shear acoustic waves remotely induced by the radiation force of a focused ultrasonic beam. SWEI provides the physician with a virtual "finger" to probe the elasticity of the internal regions of the body. In SWEI, compared to other approaches in elasticity imaging, the induced strain in the tissue can be highly localized, because the remotely induced shear waves are attenuated fully within a very limited area of tissue in the vicinity of the focal point of a focused ultrasound beam. SWEI may add a new quality to conventional ultrasonic imaging or magnetic resonance imaging. Adding shear elasticity data ("palpation information") by superimposing color-coded elasticity data over ultrasonic or magnetic resonance images may enable better differentiation of tissues and further enhance diagnosis. This article presents a physical and mathematical basis of SWEI with some experimental results of pilot studies proving feasibility of this new ultrasonic technology. A theoretical model of shear oscillations in soft biological tissue remotely induced by the radiation force of focused ultrasound is described. Experimental studies based on optical and magnetic resonance imaging detection of these shear waves are presented. Recorded spatial and temporal profiles of propagating shear waves fully confirm the results of mathematical modeling. Finally, the safety of the SWEI method is discussed, and it is shown that typical ultrasonic exposure of SWEI is significantly below the threshold of damaging effects of focused ultrasound.
Citations
More filters
Journal ArticleDOI
TL;DR: The first in vivo investigations made on healthy volunteers emphasize the potential clinical applicability of SSI for breast cancer detection and results validating SSI in heterogeneous phantoms are presented.
Abstract: Supersonic shear imaging (SSI) is a new ultrasound-based technique for real-time visualization of soft tissue viscoelastic properties. Using ultrasonic focused beams, it is possible to remotely generate mechanical vibration sources radiating low-frequency, shear waves inside tissues. Relying on this concept, SSI proposes to create such a source and make it move at a supersonic speed. In analogy with the "sonic boom" created by a supersonic aircraft, the resulting shear waves will interfere constructively along a Mach cone, creating two intense plane shear waves. These waves propagate through the medium and are progressively distorted by tissue heterogeneities. An ultrafast scanner prototype is able to both generate this supersonic source and image (5000 frames/s) the propagation of the resulting shear waves. Using inversion algorithms, the shear elasticity of medium can be mapped quantitatively from this propagation movie. The SSI enables tissue elasticity mapping in less than 20 ms, even in strongly viscous medium like breast. Modalities such as shear compounding are implementable by tilting shear waves in different directions and improving the elasticity estimation. Results validating SSI in heterogeneous phantoms are presented. The first in vivo investigations made on healthy volunteers emphasize the potential clinical applicability of SSI for breast cancer detection.

2,300 citations


Cites background or methods from "Shear wave elasticity imaging: a ne..."

  • ...[5] have linked the rise time of the longitudinal displacements to the local shear modulus:...

    [...]

  • ...[5], shear wave elasticity imaging (SWEI) and Nightingale et al....

    [...]

Journal ArticleDOI
TL;DR: Experimental results are presented demonstrating that displacements on the order of 10 microm can be generated and detected in soft tissues in vivo using a single transducer on a modified diagnostic US scanner and support the clinical feasibility of a radiation force-based remote palpation imaging system.
Abstract: The clinical viability of a method of acoustic remote palpation, capable of imaging local variations in the mechanical properties of soft tissue using acoustic radiation force impulse (ARFI) imaging, is investigated in vivo. In this method, focused ultrasound (US) is used to apply localized radiation force to small volumes of tissue (2 mm(3)) for short durations (less than 1 ms) and the resulting tissue displacements are mapped using ultrasonic correlation-based methods. The tissue displacements are inversely proportional to the stiffness of the tissue and, thus, a stiffer region of tissue exhibits smaller displacements than a more compliant region. Due to the short duration of the force application, this method provides information about the mechanical impulse response of the tissue, which reflects variations in tissue viscoelastic characteristics. In this paper, experimental results are presented demonstrating that displacements on the order of 10 microm can be generated and detected in soft tissues in vivo using a single transducer on a modified diagnostic US scanner. Differences in the magnitude of displacement and the transient response of tissue are correlated with tissue structures in matched B-mode images. The results comprise the first in vivo ARFI images, and support the clinical feasibility of a radiation force-based remote palpation imaging system.

1,085 citations

Journal ArticleDOI
TL;DR: The technical part of these Guidelines and Recommendations provides an introduction to the physical principles and technology on which all forms of current commercially available ultrasound elastography are based.
Abstract: The technical part of these Guidelines and Recommendations, produced under the auspices of EFSUMB, provides an introduction to the physical principles and technology on which all forms of current commercially available ultrasound elastography are based. A difference in shear modulus is the common underlying physical mechanism that provides tissue contrast in all elastograms. The relationship between the alternative technologies is considered in terms of the method used to take advantage of this. The practical advantages and disadvantages associated with each of the techniques are described, and guidance is provided on optimisation of scanning technique, image display, image interpretation and some of the known image artefacts.

1,020 citations

Journal ArticleDOI
TL;DR: The feasibility ofRemote palpation is demonstrated experimentally using breast tissue phantoms with spherical lesion inclusions, and in vitro liver samples and the results show promise for the clinical implementation of remote palpation.
Abstract: A method of acoustic remote palpation, capable of imaging local variations in the mechanical properties of tissue, is under investigation. In this method, focused ultrasound is used to apply localized (on the order of 2 mm3) radiation force within tissue. and the resulting tissue displacements are mapped using ultrasonic correlation based methods. The tissue displacements are inversely proportional to the stiffness of the tissue, and thus a stiffer region of tissue exhibits smaller displacements than a more compliant region. In this paper, the feasibility of remote palpation is demonstrated experimentally using breast tissue phantoms with spherical lesion inclusions, and in vitro liver samples. A single diagnostic transducer and modified ultrasonic imaging system are used to perform remote palpation. The displacement images are directly correlated to local variations in tissue stiffness with higher contrast than the corresponding B-mode images. Relationships between acoustic beam parameters, lesion characteristics and radiation force induced tissue displacement patterns are investigated and discussed. The results show promise for the clinical implementation of remote palpation.

748 citations

Journal ArticleDOI
TL;DR: The first update of the 2013 EFSUMB (European Federation of Societies for Ultrasound in Medicine and Biology) Guidelines and Recommendations on the clinical use of elastography is presented, focused on the assessment of diffuse liver disease.
Abstract: We present here the first update of the 2013 EFSUMB (European Federation of Societies for Ultrasound in Medicine and Biology) Guidelines and Recommendations on the clinical use of elastography with a focus on the assessment of diffuse liver disease. The short version provides clinical information about the practical use of elastography equipment and interpretation of results in the assessment of diffuse liver disease and analyzes the main findings based on published studies, stressing the evidence from meta-analyses. The role of elastography in different etiologies of liver disease and in several clinical scenarios is also discussed. All of the recommendations are judged with regard to their evidence-based strength according to the Oxford Centre for Evidence-Based Medicine Levels of Evidence. This updated document is intended to act as a reference and to provide a practical guide for both beginners and advanced clinical users.

740 citations


Cites background from "Shear wave elasticity imaging: a ne..."

  • ...In soft tissues, it travels at speeds in the range of 1350 – 1600ms–1, whereas shear deformation travels much slower, in the range of 1 – 10ms–1 [10]....

    [...]

References
More filters
Book
01 Jan 1934
TL;DR: The theory of the slipline field is used in this article to solve the problem of stable and non-stressed problems in plane strains in a plane-strain scenario.
Abstract: Chapter 1: Stresses and Strains Chapter 2: Foundations of Plasticity Chapter 3: Elasto-Plastic Bending and Torsion Chapter 4: Plastic Analysis of Beams and Frames Chapter 5: Further Solutions of Elasto-Plastic Problems Chapter 6: Theory of the Slipline Field Chapter 7: Steady Problems in Plane Strain Chapter 8: Non-Steady Problems in Plane Strain

20,724 citations

Book
01 Jan 1951
TL;DR: The equilibrium of rods and plates Elastic waves Dislocations Thermal conduction and viscosity in solids Mechanics of liquid crystals Index as discussed by the authors The equilibrium of rod and plate elastic waves Elastic waves
Abstract: Fundamental equations The equilibrium of rods and plates Elastic waves Dislocations Thermal conduction and viscosity in solids Mechanics of liquid crystals Index.

6,229 citations

Journal ArticleDOI
TL;DR: Initial results of several phantom and excised animal tissue experiments are reported which demonstrate the ability of this technique to quantitatively image strain and elastic modulus distributions with good resolution, sensitivity and with diminished speckle.

3,636 citations


"Shear wave elasticity imaging: a ne..." refers background in this paper

  • ...…being developed in a number of laboratories around the world (Cespedes et al. 1993; Emelianov et al. 1995; Fowlkes et al. 1995; Krouskop et al. 1987; Lerner et al. 1990; O’Donnell et al. 1994; Ophir et al. 1991, 1996; Parker et al. 1990; Skovoroda et al. 1994, 1995; Yamakoshi et al. 1990)....

    [...]

  • ...Stiffness is usually correlated with malignancy because benign lesions are supposed to be softer (10)....

    [...]

Journal ArticleDOI
TL;DR: TSH levels above 6 mu/1 were shown to reflect a significant lowering of circulating thyroxine levels and showed a strong association with thyroid antibodies in both sexes, independent of age.
Abstract: SUMMARY A survey has been conducted in Whickham, County Durham, to determine the prevalence of thyroid disorders in the community. Two thousand seven hundred and seventy-nine people (82.4% of the available sample) were seen in the survey. The prevalence of overt hyperthyroidism was 19/1000 females rising to 27/1000 females when possible cases were included, compared with 1.6–2.3/1000 males. The prevalence of overt hyothyroidism was 14/1000 females rising to 19/1000 females when possible cases were included, compared with less than 1/1000 males. The prevalence of spontaneous overt hypothyroidism (excluding iatrogenic cases) was 10/1000 females or 15/1000 females including unconfirmed cases. Minor degrees of hypothyroidism were defined on the basis of elevated serum thyrotrophin (TSH) levels in the absence of obvious clinical features of hypothyroidism. TSH levels did not vary with age in males but increased markedly in females after the age of 45 years. The rise of TSH with age in females was virtually abolished when persons with thyroid antibodies were excluded from the sample. TSH levels above 6 mu/1 were shown to reflect a significant lowering of circulating thyroxine levels and showed a strong association with thyroid antibodies in both sexes, independent of age. Elevated TSH levels (>6mu/l) were recorded in 7.5% of females and 2.8% of males of all ages. Thyroglobulin antibodies were present in 2% of the sample. Thyroid cytoplasmic antibodies were present in 6.8% of the sample (females 10.3%, males 2.7%) and their frequency did not vary significantly with age in males but increased markedly in females over 45 years of age. 3% of the sample (females 5.1%, males 1.1%) had thyroid antibodies and elevated TSH levels and the relative risk of a high TSH level in subjects with antibodies was 20:1 for males and 13:1 for females, independent of age. Small goitres (palpable but not visible) were found in 8.6% of the sample and obvious goitres (palpable and visible) in 6.9%. Goitres were four times more common in females than in males and were most commonly found in younger rather than older females. TSH levels were slightly but not significantly lower in those with goitre than in those without goitre. There was a weak association between goitre and antibodies in females but not males.

2,248 citations

Journal ArticleDOI
29 Sep 1995-Science
TL;DR: The results indicate that displacement patterns corresponding to cyclic displacements smaller than 200 nanometers can be measured and suggest the feasibility of a medical imaging technique for delineating elasticity and other mechanical properties of tissue.
Abstract: A nuclear magnetic resonance imaging (MRI) method is presented for quantitatively mapping the physical response of a material to harmonic mechanical excitation. The resulting images allow calculation of regional mechanical properties. Measurements of shear modulus obtained with the MRI technique in gel materials correlate with independent measurements of static shear modulus. The results indicate that displacement patterns corresponding to cyclic displacements smaller than 200 nanometers can be measured. The findings suggest the feasibility of a medical imaging technique for delineating elasticity and other mechanical properties of tissue.

2,015 citations


"Shear wave elasticity imaging: a ne..." refers background or methods in this paper

  • ...Several techniques have been used to detect bulk motion of materials using magnetic resonance imaging (Axel and Dougherty 1988; Decorps and Bourgeois 1991; Feinberg and Jakab 1990; Feinberg et al. 1985; Fowlkes et al. 1995; Manduca et al. 1996; Muthupillai et al. 1995; Plewes et al. 1995; Young et al. 1993; Zerhouni et al. 1988)....

    [...]

  • ...…to detect bulk motion of materials using magnetic resonance imaging (Axel and Dougherty 1988; Decorps and Bourgeois 1991; Feinberg and Jakab 1990; Feinberg et al. 1985; Fowlkes et al. 1995; Manduca et al. 1996; Muthupillai et al. 1995; Plewes et al. 1995; Young et al. 1993; Zerhouni et al. 1988)....

    [...]