Qelaxto the shear waves are lateral waves, with a motion perpendicular to the direction of the force that has generated them. 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. Dec 24, 2015 ultrafast shear wave elastography this is the technique developed by supersonic imaging also based on transient elastography ultrasound pulse. Shear wave elastography of segmental infarction of the testis article pdf available in korean journal of radiology. Pdf shearwave elastography of segmental infarction of.
Elastography can replace subjective palpation and is anticipated to image the mechanical properties of tissues and specifically their stiffness. 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. 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. Pdf introduction shearwave elastography is an emerging imaging technology that can provide an objective, noninvasive method to.
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. 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. Sep 15, 20 this video shows what are the shear waves used in sonoelastography and mr elastography imaging. In commercially available shear wave elastography systems, compressive acoustic waves are used both to induce and track shear waves. 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. Aug 17, 2017 our shear wave technology provides a quantitative measure and dynamic visual display of tissue stiffness in a variety of clinical settings. Comparison of shearwave and strain ultrasound elastography. Shear wave elastographic study of the myotendinous. The main idea is that whether the tissue is hard or soft will give diagnostic information about the presence or status of disease.
Shear wave elastography shear wave elastography is an imaging technique which quantifies tissue stiffness by measuring the speed of shear waves in tissue3. Two clinical studies of 2dswe in the liver have shown that there are several practical issues that can compromise quantitation of liver tissue elasticity. Thyroid nodules represent a common endocrine condition, being found in up to 50% of individuals on ultrasound. Shear wave elastography an overview sciencedirect topics. Shear wave elastography swe is an emerging technology that provides information about the inherent elasticity of tissues by producing an. Our shear wave technology provides a quantitative measure and dynamic visual display of tissue stiffness in a variety of clinical settings. May 25, 2017 recent studies have shown that realtime, twodimensional shear wave elastography 2dswe can monitor liver fibrosis by measuring tissue elasticity i. 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. Shear wave elastography relies on the generation of shear waves. Addition of qm can improve sw elastography sensitivity, with no significant change in specificity. Shear wave elastography for evaluation of liver fibrosis ferraioli. 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.
Comparison of smartshear wave elastography and transient. Philips shear wave elastography simplifies liver assessment, making obtaining liver stiffness measurements fast and easy. The full text of this article is available in pdf format. Us shear wave elastography is a noninvasive nonionizing imaging method that can be used to rapidly measure the stiffness of human tissue. Providing you with valuable additional information in. Animal studies have reported an increase in pelvic floor muscle stiffness during pregnancy, which might be a protective process against perineal trauma at delivery. Value of a quality measure and comparison with strain elastography1. This velocity is proportional to the square root of the tissues elasticity modulus. 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. 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. Qualitative and quantitative analysis with a novel shear. 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. The latter is a novel method which create a quantitative 2d map of the tissue stiffness.
The technique is integrated into an ultrasound system. 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. Point shear wave elastography measures the average stiffness within a small region of interest and does not show an image of stiffness. In many institutions it is replacing the need and the risk of liver biopsies for the diagnosis of cirrhosis.
Validation of shear wave elastography in skeletal muscle. Imaging of liver using shearwave elastography on aixplorer. Listing a study does not mean it has been evaluated by the u. Shear wave elastography is a type of ultrasound test. The basic principle of te is that the propagation velocity of a wave. Shear wave elastography swe has become widely accepted in clinical practice at breast centres around the world.
This diagnostic technique uses acoustic radiation force to generate in vivo shear waves. Jan 19, 2017 qualitative and quantitative analysis with a novel shear wave speed imaging for differential diagnosis of breast lesions. Objectives the myotendinous junction mtj represents a specialized anatomic region through which the contractile strength is transmitted from the muscle to the tendon. Elastography, shear wave mode elastography and elastomr. 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.
Clinical utilization of shear wave elastography in. There currently is a need for a noninvasive measure of renal fibrosis. Shear wave elastography learn more about this liver ultrasound exam. I c 1 where i denotes the temporal average intensity at a given. Apart from fibrosis, many studies demonstrated the influence of several clinical factors on liver stiffness.
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. The objective of this study is to validate swe throughout the functional range of motion of skeletal muscle for three ultrasound transducer orientations. In vivo assessment of the elastic properties of womens. Efsumb guidelines and recommendations on the clinical use. Ultrasound shear wave elastography and liver fibrosis. For shear wave elastography, elastographic im ages were generated without compression, as recommended elsewhere 12. Barr, md, phd zheng zhang, phd shear wave elastography of the breast. Shear waves created by the excitation are measured perpendicular to the. By contrast, mechanical shear waves used for shear wave elastography travel relatively slowly 110 ms. Shear wave elastography techniques use dynamic excitation to generate shear waves in the.
Point shear wave elastography is an insufficient standalone screening tool for liver fibrosis and inflammation in a heterogeneous patient population. Elastography, sonoelastography, cirrhosis, liver fibrosis, elasticity imaging techniques. Transient elastography te fibroscan, echosens, paris, france was developed in france in the early 2000s and has gained increased attention since then. Shear wave elastography wave speed or youngs modulus a measure of stiffness. Shear wave elastography will differentiate benign from. 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. Questo video mostra cosa sono le shear waves utilizzate nell. As shown in figure 1, shear waves are a type of mechanical wave which can only propagate in a solid. 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. 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.
Shear wave elastography is an increasingly popular ultrasound technique for evaluating the mechanical properties of skeletal muscle tissue. 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. Transient elastography is an example of a point shear wave elastography method. Shearwave elastography shear wave based elastography makes use of transient pulses to generate shear waves in the body 1416. 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. 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. Because the shear wave velocity depends on tissue stiffness, it is possible to shear wave elastography this document was downloaded for personal use only.
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. Limitations and artifacts in shearwave elastography of the. Shear wave elastography of passive skeletal muscle stiffness. Philips elastpq, which features ultrasound shear wave point quantification, brought significant advances to elastography. Most thyroid nodules are small and only 510% of thyroid nodules are cancerous. Qualitative and quantitative analysis with a novel shear wave. Tanter is cofounder and shareholder of supersonic imagine company. 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. Elastography is a medical imaging modality that maps the elastic properties and stiffness of soft tissue.
Shear wave ultrasound liver assessment philips ultrasound. It is important to differentiate benign from cancerous thyroid nodules, and to avoid unnecessary surgery. Participants with ckd by estimated gfr and healthy volunteers underwent swe. Virtual palpation which can overcome the subjectivity flaw and provide objective as well as quantitative measure of. Harmonic shear wave elastography ultrasound elastography for. 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. Shear wave propagation velocity depends on tissue stiffness2,4. Shear wave speed sws was measured with transient elastography, acoustic radiation force impulse arfi and 2d shear wave elastography. Shearwave elasticity imaging swei, another form of dynamic elastography, is very similar to arfi because it uses the same excitation pulse to displace the. Acoustic radiation force impulse arfi is a type of shear wave elastography. Pdf shearwave elastography of segmental infarction of the.
The tissues elasticity is directly deduced by measuring the speed of wave propagation as indicated in formula 2. Shear wave elastography radiology reference article. Mathematically speaking, the radiation force 10 generated by a propagating acoustic wave in soft tissue is given by f 2. 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. 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 in native kidney disease full text. 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. Ten valid measurements are performed in the right liver lobe, a median value is calculated and the result is expressed in meterssecond. Because it is noninvasive, shear wave elastography can offer a welltolerated and costeffective method for diagnostics. 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. It is an ultrasoundbased modality that quantitatively assesses liver stiffness ls as a surrogate for fibrosis. 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. Normal liver ultrasound and shear wave elastography.