scholarly journals Measured Hyperelastic Properties of Cervical Tissue with Shear-Wave Elastography

Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 302
Author(s):  
Weirong Ge ◽  
Graham Brooker ◽  
Ritu Mogra ◽  
Jon Hyett
Keyword(s):  
Shear Wave ◽  
Clinical Setting ◽  
Large Scale ◽  
Shear Wave Elastography ◽  
Hyperelastic Material ◽  
Nonlinear Behaviour ◽  
Cervical Tissue ◽  
Tissue Elasticity ◽  
Material Models ◽  
Shear Wave Speed

The nonlinear mechanical behaviour of cervical tissue causes unpredictable changes in measured elastograms when pressure is applied. These uncontrolled variables prevent the reliable measurement of tissue elasticity in a clinical setting. Measuring the nonlinear properties of tissue is difficult due to the need for both shear modulus and strain to be taken simultaneously. A simulation-based method is proposed in this paper to resolve this. This study describes the nonlinear behaviour of cervical tissue using the hyperelastic material models of Demiray–Fung and Veronda–Westmann. Elastograms from 33 low-risk patients between 18 and 22 weeks gestation were obtained. The average measured properties of the hyperelastic material models are: Demiray–Fung—A1α = 2.07 (1.65–2.58) kPa, α = 6.74 (4.07–19.55); Veronda–Westmann—C1C2 = 4.12 (3.24–5.04) kPa, C2 = 4.86 (2.86–14.28). The Demiray–Fung and Veronda–Westmann models performed similarly in fitting to the elastograms with an average root mean square deviation of 0.41 and 0.47 ms−1, respectively. The use of hyperelastic material models to calibrate shear-wave speed measurements improved the consistency of measurements. This method could be applied in a large-scale clinical setting but requires updated models and higher data resolution.

Evaluation of Ovaries in Patients with Polycystic Ovary Syndrome using Shear Wave Elastography

2020 ◽  
Vol 16 (5) ◽  
pp. 578-583
Author(s):  
Aysegul Altunkeser ◽  
Zeynep Ozturk Inal ◽  
Nahide Baran
Keyword(s):  
Shear Wave ◽  
Large Scale ◽  
Polycystic Ovary ◽  
Shear Wave Elastography ◽  
Left Ovary ◽  
Control Group ◽  
Tissue Elasticity ◽  
Group I ◽  
Pcos Group ◽  
The Right

Background: Shear wave electrography (SWE) is a novel non-invasive imaging technique which demonstrate tissue elasticity. Recent research evaluating the elasticity properties of normal and pathological tissues emphasize the diagnostic importance of this technique. Aims: Polycystic ovarian syndrome (PCOS), which is characterized by menstrual irregularity, hyperandrogenism, and polycystic overgrowth, may cause infertility. The aim of this study was to evaluate the elasticity of ovaries in patients with PCOS using SWE. Methods: 66 patients diagnosed with PCOS according to the Rotterdam criteria (PCOS = group I) and 72 patients with non-PCOS (Control = group II), were included in the study. Demographic and clinical characteristics of the participants were recorded. Ovarian elasticity was assessed in all patients with SWE, and speed values were obtained from the ovaries. The elasticity of the ovaries was compared between the two groups. Results: While there were statistically significant differences between the groups in body mass index (BMI), right and left ovarian volumes, luteinizing hormone and testosterone levels (p<0.05), no significant differences were found between groups I and II in the velocity (for the right ovary 3.89±1.81 vs. 2.93±0.72, p=0.301; for the left ovary 2.88±0.65 vs. 2.95±0.80, p=0.577) and elastography (for the right ovary 36.62±17.78 vs. 36.79±14.32, p=0.3952; for the left ovary 36.56±14.15 vs. 36.26±15.10, p=0.903) values, respectively. Conclusion: We could not obtain different velocity and elastography values from the ovaries of the patients with PCOS using SWE. Therefore, further large-scale studies are needed to elucidate this issue.

Diagnostic Value of Real-Time Shear Wave Elastography in Diagnosing Thyroid Cancer

2018 ◽  
Vol 68 (12) ◽  
pp. 2818-2822
Author(s):  
Maria Cristina Oprea ◽  
Mihaela Vlad ◽  
Ioana Golu ◽  
Ioan Sporea ◽  
Lazar Fulger
Keyword(s):  
Shear Wave ◽  
Predictive Value ◽  
Thyroid Nodules ◽  
Imaging Techniques ◽  
Area Under The Curve ◽  
Thyroid Volume ◽  
Shear Wave Elastography ◽  
Maximum Diameter ◽  
Diagnostic Tools ◽  
Tissue Elasticity

Thyroid nodules are a common pathology found in 50 to 60% of otherwise healthy people. Diagnostic imaging techniques are help discriminating between benign and malignant nodules, while fine needle aspiration is still a gold standard. Shear wave elastography, a recent imaging technique, holds the promise to become reliable diagnostic tools and is currently used in combination with ultrasound. We here report data obtained in a series of 52 thyroid nodules analysed by means of elastography, as well as conventional and Doppler ultrasound. We found no differences in age, nodule and thyroid volume, length, width, thickness and maximum diameter between benign and malignant lesions. Several sonographic patterns are considered to be predictive of malignancy, out of which we only found the intranodular blood flow to be statistically significant. By the means of shear wave elastography we have first assessed tissue elasticities, which are shown in a range of colours, depending on tissue elasticity/stiffness. Then, we have measured and recorded four parameters automatically displayed by the system, namely SWE-mean, SWE-max, SWE-SD and SWE-ratio. Data analysis showed all these quantitative parameters had good sensitivity, specificity, positive predictive value, negative predictive value and area under the curve, as calculated by the ROC curve. As with these parameters, the cut-off points were lower than in literature, still able to indicate reliable diagnoses, which were confirmed by histopathological exam. Our conclusion is that shear wave elastography has great potential for reliably and accurately diagnosing thyroid malignancies.

Shear wave elastography of thyroid nodules for the prediction of malignancy in a large scale study

2015 ◽  
Vol 84 (3) ◽  
pp. 407-412 ◽  
Author(s):  
Ah Young Park ◽  
Eun Ju Son ◽  
Kyunghwa Han ◽  
Ji Hyun Youk ◽  
Jeong-Ah Kim ◽  
...  
Keyword(s):  
Shear Wave ◽  
Large Scale ◽  
Thyroid Nodules ◽  
Shear Wave Elastography ◽  
Large Scale Study

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 Comparison of Two-Dimensional Shear Wave Elastography and Point Shear Wave Elastography for Assessing Liver Fibrosis

2019 ◽  
Author(s):  
Xiaozhuan Zhou ◽  
Jiawei Rao ◽  
Xukun Wu ◽  
Ronghai Deng ◽  
Yi Ma
Keyword(s):  
Liver Fibrosis ◽  
Shear Wave ◽  
Large Scale ◽  
Characteristic Curve ◽  
Shear Wave Elastography ◽  
Cochrane Library ◽  
Two Dimensional ◽  
Advanced Fibrosis ◽  
Likelihood Ratios ◽  
Significant Fibrosis

Abstract Background: Progressive liver fibrosis may result in cirrhosis, portal hypertension, and hepatocellular carcinoma (HCC). We performed a meta-analysis to compare liver fibrosis staging in chronic liver disease patients using two-dimensional shear wave elastography (2D-SWE) and point shear wave elastography (pSWE). Methods: PubMed, Web of Science, and Cochrane Library databases were searched until September 30th 2019 for studies evaluating the diagnostic performance of 2D-SWE and pSWE for assessing liver fibrosis. Pooled sensitivity, specificity, positive and negative likelihood ratios, diagnostic odds ratios, and area under receiver operating characteristic curve (AUC) were estimated using the bivariate random effects model. Results: Eighteen studies with 3,082 patients were included in the analysis. The pooled sensitivities of 2D-SWE and pSWE were significantly different for the detection of significant fibrosis (0.83 vs. 0.70, P < 0.001) and advanced fibrosis (0.89 vs. 0.78, P < 0.05), but not for detection of cirrhosis (0.87 vs. 0.83, P > 0.05). The pooled specificities of 2D-SWE and pSWE were not significantly different for detection of significant fibrosis (0.83 vs. 0.83, P > 0.05), advanced fibrosis (0.80 vs. 0.85, P > 0.05), or cirrhosis (0.84 vs. 0.88, P > 0.05). Conclusions: Both 2D-SWE and pSWE have high sensitivity and specificity for detecting each stage of liver fibrosis. 2D-SWE has higher sensitivity than pSWE for detection of significant fibrosis and advanced fibrosis. Large-scale and multi-center studies are needed to directly compare 2D-SWE and pSWE.

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.

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