Basic investigation on identification of tissue composition based on propagation speeds of longitudinal and shear waves

2021 ◽  
Author(s):  
Naotaka NITTA ◽  
Toshikatsu Washio ◽  
Tomokazu Numano
Keyword(s):  
Shear Wave ◽  
Wave Speed ◽  
Shear Wave Elastography ◽  
Disease Detection ◽  
Good Sensitivity ◽  
Tissue Composition ◽  
Tissue Properties ◽  
Shear Wave Speed ◽  
Longitudinal And Shear Waves ◽  
The Relationship

Abstract The elastic modulus of tissue as a useful biomarker of disease detection can be quantitatively evaluated based on shear wave speed (SWS) measurements in shear wave elastography. Although the longitudinal wave speed (LWS) is also expected to be a promising biomarker for disease detection, the elasticity is not always dominant because the LWS is affected by the bulk modulus. In other words, LWS and SWS may reflect different tissue properties. Therefore, in this study, based on the improvement in LWS measurement, the relationship between the composition of a phantom mixed with agar and glycerol and ultrasonically measured LWS and SWS was investigated. The LWS had a good sensitivity in detecting glycerol, while the SWS had a good sensitivity in detecting agar. The calculated Poisson's ratio had a better sensitivity in detecting agar. In conclusion, a simultaneous measurement of LWS and SWS may help identify the tissue composition.

scholarly journals A soft cervix, categorized by shear-wave elastography, in women with short or with normal cervical length at 18–24 weeks is associated with a higher prevalence of spontaneous preterm delivery

2018 ◽  
Vol 46 (5) ◽  
pp. 489-501 ◽  
Author(s):  
Edgar Hernandez-Andrade ◽  
Eli Maymon ◽  
Suchaya Luewan ◽  
Gaurav Bhatti ◽  
Mohammad Mehrmohammadi ◽  
...  
Keyword(s):  
Cohort Study ◽  
Preterm Delivery ◽  
Shear Wave ◽  
Wave Speed ◽  
Shear Wave Elastography ◽  
Cervical Length ◽  
Singleton Pregnancy ◽  
Short Cervix ◽  
Shear Wave Speed ◽  
Spontaneous Preterm Delivery

AbstractObjective:To determine whether a soft cervix identified by shear-wave elastography between 18 and 24 weeks of gestation is associated with increased frequency of spontaneous preterm delivery (sPTD).Materials and methods:This prospective cohort study included 628 consecutive women with a singleton pregnancy. Cervical length (mm) and softness [shear-wave speed: (SWS) meters per second (m/s)] of the internal cervical os were measured at 18–24 weeks of gestation. Frequency of sPTD <37 (sPTD<37) and <34 (sPTD<34) weeks of gestation was compared among women with and without a short (≤25 mm) and/or a soft cervix (SWS <25thpercentile).Results:There were 31/628 (4.9%) sPTD<37 and 12/628 (1.9%) sPTD<34 deliveries. The combination of a soft and a short cervix increased the risk of sPTD<37 by 18-fold [relative risk (RR) 18.0 (95% confidence interval [CI], 7.7–43.9); P<0.0001] and the risk of sPTD<34 by 120-fold [RR 120.0 (95% CI 12.3–1009.9); P<0.0001] compared to women with normal cervical length. A soft-only cervix increased the risk of sPTD<37 by 4.5-fold [RR 4.5 (95% CI 2.1–9.8); P=0.0002] and of sPTD<34 by 21-fold [RR 21.0 (95% CI 2.6–169.3); P=0.0003] compared to a non-soft cervix.Conclusions:A soft cervix at 18–24 weeks of gestation increases the risk of sPTD <37 and <34 weeks of gestation independently of cervical length.

scholarly journals Strain Elastography - How To Do It?

2017 ◽  
Vol 03 (04) ◽  
pp. E137-E149 ◽  
Author(s):  
Christoph Dietrich ◽  
Richard Barr ◽  
André Farrokh ◽  
Manjiri Dighe ◽  
Michael Hocke ◽  
...  
Keyword(s):  
Shear Wave ◽  
Wave Speed ◽  
Shear Wave Elastography ◽  
Ultrasound Elastography ◽  
Tissue Stiffness ◽  
Shear Wave Speed ◽  
Strain Elastography ◽  
Advantages And Disadvantages ◽  
Similar Information ◽  
Qualitative Technique

AbstractTissue stiffness assessed by palpation for diagnosing pathology has been used for thousands of years. Ultrasound elastography has been developed more recently to display similar information on tissue stiffness as an image. There are two main types of ultrasound elastography, strain and shear wave. Strain elastography is a qualitative technique and provides information on the relative stiffness between one tissue and another. 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 meters/second, or converted to the Young’s modulus making some assumptions and expressed in kPa. Each technique has its advantages and disadvantages and they are often complimentary to each other in clinical practice. This article reviews the principles, technique, and interpretation of strain elastography in various organs. It describes how to optimize technique, while pitfalls and artifacts are also discussed.

scholarly journals A Cross-Machine Comparison of Shear-Wave Speed Measurements Using 2D Shear-Wave Elastography in the Normal Female Breast

2021 ◽  
Vol 11 (20) ◽  
pp. 9391
Author(s):  
Emma Harris ◽  
Ruchi Sinnatamby ◽  
Elizabeth O’Flynn ◽  
Anna M. Kirby ◽  
Jeffrey C. Bamber
Keyword(s):  
Adipose Tissue ◽  
Shear Wave ◽  
Subcutaneous Adipose Tissue ◽  
Wave Speed ◽  
Shear Wave Elastography ◽  
Shear Wave Speed ◽  
Skin Region ◽  
Subcutaneous Adipose

Quantitative measures of radiation-induced breast stiffness are required to support clinical studies of novel breast radiotherapy regimens and exploration of personalised therapy, however, variation between shear-wave elastography (SWE) machines may limit the usefulness of shear-wave speed (cs) for this purpose. Mean cs measured in four healthy volunteers’ breasts and a phantom using 2D-SWE machines Acuson S2000 (Siemens Medical Solutions) and Aixplorer (Supersonic Imagine) were compared. Shear-wave speed was measured in the skin region, subcutaneous adipose tissue and parenchyma. cs estimates were on average 2.3% greater when using the Aixplorer compared to S2000 in vitro. In vivo, cs estimates were on average 43.7%, 36.3% and 49.9% significantly greater (p << 0.01) when using the Aixplorer compared to S2000, for skin region, subcutaneous adipose tissue and parenchyma, respectively. In conclusion, despite relatively small differences between machines observed in vitro, large differences in absolute measures of shear wave speed measured were observed in vivo, which may prevent pooling of cross-machine data in clinical studies of the breast.

scholarly journals Feasibility and Reliability of Two-Dimensional Shear-Wave Elastography of the Liver of Clinically Healthy Cats

2020 ◽  
Vol 7 ◽  
Author(s):  
Kyeonga Kim ◽  
Jieun Lee ◽  
Jaebeom So ◽  
Yong-seok Jang ◽  
Mingyu Jung ◽  
...  
Keyword(s):  
Shear Wave ◽  
Wave Speed ◽  
Liver Stiffness ◽  
Shear Wave Elastography ◽  
Acoustic Radiation Force Impulse ◽  
Breath Holding ◽  
Two Dimensional ◽  
Shear Wave Speed ◽  
Left Liver ◽  
The Right

Given the broad overlap of normal and abnormal liver tissue in the subjective evaluation of the liver in conventional B-mode ultrasonography, there is a need for a non-invasive and quantitative method for the diagnosis of liver disease. Novel two-dimensional shear-wave elastography (2-D SWE) can measure tissue stiffness by propagation of the shear wave induced using acoustic radiation force impulse in real time. To the best of our knowledge, two-dimensional shear-wave measurement of the liver in cats has not been reported to date. This study assessed the feasibility, reliability, normal values, and related influencing factors of 2-D SWE for assessment of the feline liver without anesthesia and breath-holding. Two-dimensional shear-wave ultrasonography was performed by two evaluators at the right and left sides of the liver. Twenty-nine client-owned clinically healthy adult cats were included. The means and standard deviations for the shear-wave speed and stiffness in the right liver were 1.52 ± 0.13 m/s and 6.94 ± 1.26 kPa, respectively, and those for the left liver were 1.61 ± 0.15 m/s and 7.90 ± 1.47 kPa, respectively. Shear-wave speed (P = 0.005) and stiffness (P = 0.002) were significantly lower in the right liver when compared to the left. The intraclass correlation value for liver stiffness was 0.835 and 0.901 for the right and left liver, respectively, indicating high interobserver agreement. Age, weight, body condition score (BCS), gabapentin administration, and measurement depths were not significantly correlated with liver stiffness or elastography measurements (P &gt; 0.05). Our findings suggest that 2-D SWE measurements of the liver are not influenced significantly by age, weight, or BCS and can be reliably performed without anesthesia and breath-holding in cats. The values determined here can help form the basis for reference elastography values for evaluation of the feline liver.

Modern sonographic markers for the prognosis of preterm birth in women with different somatotypes

2021 ◽  
Vol 70 (4) ◽  
pp. 91-98
Author(s):  
Kristina G. Tomaeva ◽  
Sergey N. Gaidukov ◽  
Elena N. Komissarova ◽  
Georgii G, Tomaev
Keyword(s):  
Preterm Birth ◽  
Pregnant Women ◽  
Shear Wave ◽  
Wave Speed ◽  
Shear Wave Elastography ◽  
Test Method ◽  
Shear Wave Speed ◽  
Risk Of Death ◽  
Increased Risk ◽  
Average Shear

BACKGROUND:Preterm birth is one of the causes of perinatal morbidity and mortality. Premature infants have an increased risk of death and the development of neurological and other disorders. AIM:The aim of this study was to evaluate the modern sonographic parameters of the cervix in pregnant women with different somatotypes and to develop a mathematical model for predicting preterm birth. MATERIALS AND METHODS:The study included 390 women, among whom 110 were classified with macrosomatic, 173 with mesosomatic, and 107 with microsomatic types. Somatotype was determined in women in early stages of pregnancy (before 9-10 weeks of gestation) using the R.N. Dorokhov anthropometric test method. The utero-cervical angle was measured, shear wave elastography was performed, and the average shear wave speed in the area of the internal cervical os was determined. All measurements were performed on a Philips EPIQ 5 ultrasound machine. RESULTS:Preterm birth was more often identified in women with macro- and microsomatic types in comparison with women with mesosomatic type (p 0.05). In pregnant women with subsequent preterm birth at 22-23 weeks, the average SWS in the area of the internal cervical os was reduced (p 0.05) and the utero-cervical angle was higher in comparison with those women who did not have preterm birth (p 0.05). Using multiple regression analysis, we obtained the regression equation (formula), which predicts the development of preterm birth in women with different somatotypes. CONCLUSIONS:Such parameters as the average shear wave speed in the area of the internal cervical os and the utero-cervical angle may be regarded as markers of preterm birth. The mathematical formula obtained allows for predicting the development of preterm birth in women with different somatotypes and for timely prevention of pathology.

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