scholarly journals Ultrasound Shear Wave Simulation of Breast Tumor Using Nonlinear Tissue Elasticity

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Dae Woo Park

Shear wave elasticity imaging (SWEI) can assess the elasticity of tissues, but the shear modulus estimated in SWEI is often less sensitive to a subtle change of the stiffness that produces only small mechanical contrast to the background tissues. Because most soft tissues exhibit mechanical nonlinearity that differs in tissue types, mechanical contrast can be enhanced if the tissues are compressed. In this study, a finite element- (FE-) based simulation was performed for a breast tissue model, which consists of a circular (D: 10 mm, hard) tumor and surrounding tissue (soft). The SWEI was performed with 0% to 30% compression of the breast tissue model. The shear modulus of the tumor exhibited noticeably high nonlinearity compared to soft background tissue above 10% overall applied compression. As a result, the elastic modulus contrast of the tumor to the surrounding tissue was increased from 0.46 at 0% compression to 1.45 at 30% compression.

BMC Cancer ◽  
2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Hui Yang ◽  
Yongyuan Xu ◽  
Yanan Zhao ◽  
Jing Yin ◽  
Zhiyi Chen ◽  
...  

Abstract Background Elastography is a promising way to evaluate tissue differences regarding stiffness, and the stiffness of the malignant breast lesions increased at the lesion margin. However, there is a lack of data on the value of the shear wave elastography (SWE) parameters of the surrounding tissue (shell) of different diameter on the diagnosis of benign and malignant breast lesions. Therefore, the purpose of our study was to evaluate the diagnostic performance of shell elasticity in the diagnosis of benign and malignant breast lesions using SWE. Methods Between September 2016 and June 2017, women with breast lesions underwent both conventional ultrasound (US) and SWE. Elastic values of the lesions peripheral tissue were determined according to the shell size, which was automatically drawn along the edge of the lesion using the following software guidelines: (1): 1 mm; (2): 2 mm; and (3): 3 mm. Quantitative elastographic features of the inner lesions and shell, including the elasticity mean (Emean), elasticity maximum (Emax), and elasticity minimum (Emin), were calculated using an online-available software. The receiver operating characteristic curves (ROCs) of the elastographic features was analyzed to assess the diagnostic performance, and the area under curve (AUC) of each elastographic feature was obtained. Logistic regression analysis was used to predict significant factors of malignancy, permitting the design of predictive models. Results This prospective study included 63 breast lesions of 63 women. Of the 63 lesions, 33 were malignant and 30 were benign. The diagnostic performance of Emax-3shell was the highest (AUC = 0.76) with a sensitivity of 60.6% and a specificity of 83.3%. According to stepwise logistic regression analysis, the Emax-3shell and the Emin-3shell were significant predictors of malignancy (p < 0.05). The AUC of the predictive equation was 0.86. Conclusions SWE features, particularly the combination of Emax-3shell and Emin-3shell can improve the diagnosis of breast lesions.


2021 ◽  
Vol 9 ◽  
Author(s):  
Bhaskara R. Chintada ◽  
Richard Rau ◽  
Orcun Goksel

Shear wave elasticity imaging (SWEI) is a non-invasive imaging modality that provides tissue elasticity information by measuring the travelling speed of an induced shear-wave. It is commercially available on clinical ultrasound scanners and popularly used in the diagnosis and staging of liver disease and breast cancer. In conventional SWEI methods, a sequence of acoustic radiation force (ARF) pushes are used for inducing a shear-wave, which is tracked using high frame-rate multi-angle plane wave imaging (MA-PWI) to estimate the shear-wave speed (SWS). Conventionally, these plane waves are beamformed using a constant speed-of-sound (SoS), assuming an a-priori known and homogeneous tissue medium. However, soft tissues are inhomogeneous, with intrinsic SoS variations. In this work, we study the SoS effects and inhomogeneities on SWS estimation, using simulation and phantoms experiments with porcine muscle as an abbarator, and show how these aberrations can be corrected using local speed-of-sound adaptive beamforming. For shear-wave tracking, we compare standard beamform with spatially constant SoS values to software beamforming with locally varying SoS maps. We show that, given SoS aberrations, traditional beamforming using a constant SoS, regardless of the utilized SoS value, introduces a substantial bias in the resulting SWS estimations. Average SWS estimation disparity for the same material was observed over 4.3 times worse when a constant SoS value is used compared to that when a known SoS map is used for beamforming. Such biases are shown to be corrected by using a local SoS map in beamforming, indicating the importance of and the need for local SoS reconstruction techniques.


2018 ◽  
Vol 68 (12) ◽  
pp. 2818-2822
Author(s):  
Maria Cristina Oprea ◽  
Mihaela Vlad ◽  
Ioana Golu ◽  
Ioan Sporea ◽  
Lazar Fulger

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.


Author(s):  
Aysegul Altunkeser ◽  
Zeynep Ozturk Inal ◽  
Nahide Baran

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.


Author(s):  
Courtney A. Trutna ◽  
Anna E. Knight ◽  
Ned C. Rouze ◽  
Lisa D. Hobson-Webb ◽  
Mark L. Palmeri ◽  
...  

2021 ◽  
Vol 59 (2) ◽  
pp. 383-390
Author(s):  
Baizhen Chen ◽  
Chunlong Liu ◽  
Ming Lin ◽  
Weixin Deng ◽  
Zhijie Zhang

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