Elastography, sonoelastography, cirrhosis, liver fibrosis, elasticity imaging techniques. Studies have demonstrated that swe has reduced the number of unnecessary biopsies, helped prevent false negative diagnoses, and improved overall diagnostic confidence and patient management berg et al. Dynamic elastography techniques, which rely on shear waves propagation, can produce quantitative and higher resolution youngs modulus map compared to quasistatic methods. Shear wave elastography relies on the generation of shear waves determined by the displacement of tissues induced by the force of a focused ultrasound beam or by an external push.
This noninvasive, reproducible, and easily performed method of assessing liver tissue stiffness may help reduce, or even avoid, the need for conventional liver biopsies 1. Philips elastpq, which features ultrasound shear wave point quantification, brought significant advances to elastography. Qualitative and quantitative analysis with a novel shear wave speed imaging for differential diagnosis of breast lesions. Shear wave elastography is a quantitative method and provides an estimated value of the tissue stiffness that can be expressed in either the shear wave speed through the tissues in meterssecond. Vtq arfi elastography is a new method developed in the last 56 years for the noninvasive evaluation of liver fibrosis, integrated into a siemens acuson ultrasound system. Pdf shearwave elastography of segmental infarction of the. Barr, md, phd zheng zhang, phd shear wave elastography of the breast. Physics of elastography elastography is a noninvasive technique of imaging stiffness or elasticity of tissues by measuring movement or transformation of tissue in response to a small applied pressure. The lesions were located at the center of the elasticity boxes, and the shear wave elastography images of the lesions were saved after a few seconds of immobilization to allow the shear wave elastography image to sta bilize. Transient elastography is an example of a point shear wave elastography method. It is an ultrasoundbased modality that quantitatively assesses liver stiffness ls as a surrogate for fibrosis.
Virtual palpation which can overcome the subjectivity flaw and provide objective as well as quantitative measure of. However they allow the generation of multiple shear wave along a same longitudinal axis through a compression wave leading to the propagation of a plane shear wave. The tissues elasticity is directly deduced by measuring the speed of wave propagation as indicated in formula 2. Normal liver ultrasound and shear wave elastography. Mar 11, 2016 with shear wave elastography swe a quantitative measure of the lesion stiffness is obtained either in a region of interest roi, point quantification swe pswe or pixelbypixel using a color map, 2d swe. Philips shear wave elastography simplifies liver assessment, making obtaining liver stiffness measurements fast and easy.
Transient elastography te has been validated in multiple studies but shear wave elastography swe may be preferred because unlike transient elastography, which consists of a vibrator producing shear waves, the latter can perform a conventional ultrasound at the same time. Shearwave elastography shear wave based elastography makes use of transient pulses to generate shear waves in the body 1416. Shear wave elastography radiology reference article. Shear wave propagation velocity depends on tissue stiffness2,4. Sep 15, 20 this video shows what are the shear waves used in sonoelastography and mr elastography imaging. Aug 17, 2017 our shear wave technology provides a quantitative measure and dynamic visual display of tissue stiffness in a variety of clinical settings. Both general ultrasound us limitations and limitations in the 2d. Shear wave elastography is a developing variation of ultrasound imaging the concept is similar to strain elastography, but instead of using transducer pressure to compare a shift in an ultrasound aline thereby measuring changes in strain, a higher intensity pulse is transmitted to produce shear waves, which extend laterally from the insonated structure. I c 1 where i denotes the temporal average intensity at a given. Shear wave elastography an overview sciencedirect topics. During this exam, we scan the density of your liver tissue to determine whether you have a condition called hepatic fibrosis, a rare disease in which there is excess protein buildup in the liver.
Clinical utilization of shear wave elastography in. Pdf shearwave elastography of segmental infarction of. Oct 24, 2017 in this paper we present a preliminary comparative study of two types of ultrasound elastography techniques strain elastography and shear wave elastography. In this paper, we focus on dynamic shearwave elastography through the results are generalizable to other variations of elastography. Dec 24, 2015 ultrafast shear wave elastography this is the technique developed by supersonic imaging also based on transient elastography ultrasound pulse. Comparison of smartshear wave elastography and transient. Questo video mostra cosa sono le shear waves utilizzate nell.
Shear wave elastography swe has become widely accepted in clinical practice at breast centres around the world. Ten valid measurements are performed in the right liver lobe, a median value is calculated and the result is expressed in meterssecond. Harmonic shear wave elastography ultrasound elastography for. This video shows what are the shear waves used in sonoelastography and mr elastography imaging. As shown in figure 1, shear waves are a type of mechanical wave which can only propagate in a solid. Two clinical studies of 2dswe in the liver have shown that there are several practical issues that can compromise quantitation of liver tissue elasticity. Shear wave elastography in native kidney disease full text. Shearwave elastography we hypothesize that vtiq may provide a noninvasive sensitive means for absolute quantification of skin stiffness, which may have considerable impact upon clinical. Shearwave elasticity imaging swei, another form of dynamic elastography, is very similar to arfi because it uses the same excitation pulse to displace the. In commercially available shear wave elastography systems, compressive acoustic waves are used both to induce and track shear waves. Shear wave elastography is an increasingly popular ultrasound technique for evaluating the mechanical properties of skeletal muscle tissue. Listing a study does not mean it has been evaluated by the u.
The basic principle of te is that the propagation velocity of a wave. Oct 07, 2015 comparison of smart shear wave elastography and transient elastography smart the safety and scientific validity of this study is the responsibility of the study sponsor and investigators. May 25, 2017 recent studies have shown that realtime, twodimensional shear wave elastography 2dswe can monitor liver fibrosis by measuring tissue elasticity i. Shearwave elastography swe performed with aixplorer is a 2d imaging mode3,4 that provides a view of the organ and a map of stiffness over the region of interest from soft to hard color. By contrast, mechanical shear waves used for shear wave elastography travel relatively slowly 110 ms. Shear wave elastography shear wave elastography is an imaging technique which quantifies tissue stiffness by measuring the speed of shear waves in tissue3. Value of a quality measure and comparison with strain elastography1. Shear wave elastography will differentiate benign from. In many institutions it is replacing the need and the risk of liver biopsies for the diagnosis of cirrhosis. Pdf introduction shearwave elastography is an emerging imaging technology that can provide an objective, noninvasive method to. The purpose of this study was to quantify the passive stiffness, or shear modulus, of the biceps brachii throughout adulthood in flexed and extended elbow positions. Shear wave elastography for evaluation of liver fibrosis ferraioli.
This diagnostic technique uses acoustic radiation force to generate in vivo shear waves. Qelaxto the shear waves are lateral waves, with a motion perpendicular to the direction of the force that has generated them. The latter is a novel method which create a quantitative 2d map of the tissue stiffness. Summary this chapter introduces the basic principles of the harmonic shear wave elastography hswe. Shear wave elastography relies on the generation of shear waves.
There currently is a need for a noninvasive measure of renal fibrosis. Any information contained in this pdf file is automatically generated from digital material submitted to epos by third parties in the form of scientific presentations. Shear wave based elastography is the only approach able to. Acoustic radiation force impulse arfi is a type of shear wave elastography. Now, the introduction of shear wave philips elastq imaging provides realtime feedback, greater confidence in quantification, and speed to advance the use of elastography in clinical practice. Shear wave elastography swe is an emerging technology that provides information about the inherent elasticity of tissues by producing an. Shearwave elastography of segmental infarction of the testis article pdf available in korean journal of radiology. The use of shear waves, however, requires a more complex system, able to generate the shear wave mechanical vibrator or ultrasound radiation pressure and to image the. Shear wave elastography of passive skeletal muscle stiffness. Shear wave elastography of segmental infarction of the testis article pdf available in korean journal of radiology. Limitations and artifacts in shearwave elastography of the. The full text of this article is available in pdf format. Ultrasound shear wave elastography and liver fibrosis. This velocity is proportional to the square root of the tissues elasticity modulus.
Validation of shear wave elastography in skeletal muscle. Shear wave elastography wave speed or youngs modulus a measure of stiffness. Comparison of shearwave and strain ultrasound elastography. Jul 12, 2016 shear wave elastography in native kidney disease the safety and scientific validity of this study is the responsibility of the study sponsor and investigators. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Our shear wave technology provides a quantitative measure and dynamic visual display of tissue stiffness in a variety of clinical settings. Because the shear wave velocity depends on tissue stiffness, it is possible to shear wave elastography this document was downloaded for personal use only. Point shear wave elastography is an insufficient standalone screening tool for liver fibrosis and inflammation in a heterogeneous patient population. Us shear wave elastography is a noninvasive nonionizing imaging method that can be used to rapidly measure the stiffness of human tissue. We aim to explore whether shear wave elastography swederived estimates of tissue stiffness may serve as a noninvasive biomarker that can distinguish normal and abnormal renal parenchymal tissue. Jan 08, 2017 transient elastography te has been validated in multiple studies but shear wave elastography swe may be preferred because unlike transient elastography, which consists of a vibrator producing shear waves, the latter can perform a conventional ultrasound at the same time. Point shear wave elastography measures the average stiffness within a small region of interest and does not show an image of stiffness. Apart from fibrosis, many studies demonstrated the influence of several clinical factors on liver stiffness. Shear waves created by the excitation are measured perpendicular to the.
Mathematically speaking, the radiation force 10 generated by a propagating acoustic wave in soft tissue is given by f 2. Participants with ckd by estimated gfr and healthy volunteers underwent swe. Elastography as a noninvasive tool to simplify liver assessment 2 liver shear wave elastography provides stiffness measurements for assessment of diffuse liver disease and possibly neoplastic lesions of the liver. Sep 27, 20 shear wave elastography swe is an ultrasoundbased technique that characterizes tissue mechanical properties based on the propagation of remotely induced shear waves. Thyroid nodules represent a common endocrine condition, being found in up to 50% of individuals on ultrasound. In this technique, a dynamic stress is applied to tissue by using a mechanical vibrating device in 1d transient elastography 1dte or acoustic radiation force in point shear wave elastography pswe and 2d shear wave elastography 2d swe. Examples of a benign and malignant lesion are presented in fig. For shear wave elastography, elastographic im ages were generated without compression, as recommended elsewhere 12. Elastography is a medical imaging modality that maps the elastic properties and stiffness of soft tissue. In vivo assessment of the elastic properties of womens. It is important to differentiate benign from cancerous thyroid nodules, and to avoid unnecessary surgery. Qualitative and quantitative analysis with a novel shear. The objective of this study is to validate swe throughout the functional range of motion of skeletal muscle for three ultrasound transducer orientations.
Animal studies have reported an increase in pelvic floor muscle stiffness during pregnancy, which might be a protective process against perineal trauma at delivery. Efsumb guidelines and recommendations on the clinical use. Shear wave ultrasound liver assessment philips ultrasound. Addition of qm can improve sw elastography sensitivity, with no significant change in specificity. Shear wave elastographic study of the myotendinous. Elastography can replace subjective palpation and is anticipated to image the mechanical properties of tissues and specifically their stiffness. Qualitative and quantitative analysis with a novel shear wave. Jan 19, 2017 qualitative and quantitative analysis with a novel shear wave speed imaging for differential diagnosis of breast lesions. Transient elastography te fibroscan, echosens, paris, france was developed in france in the early 2000s and has gained increased attention since then. Objectives the myotendinous junction mtj represents a specialized anatomic region through which the contractile strength is transmitted from the muscle to the tendon.
Providing you with valuable additional information in. Elastography, shear wave mode elastography and elastomr. Tanter is cofounder and shareholder of supersonic imagine company. Shear wave elastography techniques use dynamic excitation to generate shear waves in the. Shear wave speed sws was measured with transient elastography, acoustic radiation force impulse arfi and 2d shear wave elastography. Imaging of liver using shearwave elastography on aixplorer. Most thyroid nodules are small and only 510% of thyroid nodules are cancerous.
Shear wave elastography learn more about this liver ultrasound exam. The technique is integrated into an ultrasound system. Shear wave elastography is a type of ultrasound test. Because it is noninvasive, shear wave elastography can offer a welltolerated and costeffective method for diagnostics.
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