Application Of Shear Wave Elastography Research Articles

Use of Shear Wave Elastography in the Sonographic Triage of Thyroid Nodules: Feasibility Study in a Series of Lesions Already Selected for Fine Needle Aspiration.

The aim of this study was to evaluate the application of shear wave elastography (SWE) in the routine management of thyroid nodules, as a possible additional tool to the standard sonographic triage. A total of 248 consecutive patients scheduled for ultrasound-guided thyroid fine-needle aspiration were included in the study. The presence of a pure colloid lesion was an exclusion criterion. Absolute and relative SWE stiffness measurements on color-coded elastograms, expressed in kilopascals and meters per second, were correlated with radiologic and pathologic features. SWE values in thyroid nodules were significantly higher than normal thyroid tissue (P = .0001), proving the different elastic properties of the pathologic tissues. Regarding the radiologic characteristics of the nodules, SWE highest values were associated with the largest lesions (P = .0105) but independent from sonographic and Doppler findings. The SWE elasticity was not influenced by the characteristics of the biopsy smears. The final correlation between the SWE results and the pathologic diagnoses showed a trend in stiffness from tender tumors (follicular adenoma) to papillary thyroid carcinoma (P = .016). SWE allows the identification of nodules within normal parenchyma; however, the present study does not confirm the potential role in differentiating between benign and malignant thyroid nodules.

Application of shear wave elastography in the study of renal tissue elasticity in patients with diabetic nephropathy

Objective To investigate the clinical value of real-time shear wave elastography(SWE) in early diagnosis of diabetic nephropathy(DN). Methods One hundred and fifty-five patients with type 2 diabetes mellitus (DM) in our hospital were selected as DN group and 54 healthy volunteers with matched age-sex were selected as control group. According to the criteria of Mogensen staging, patients of DN group were divided into 3 subgroups according to urine protein/creatinine (ACR): group A (DM or DN Ⅰ, Ⅱ), ACR 300 mg/g. All subjects were examined by SWE technique to detect the maximum, mean and minimum Young′s modulus values (Emax, Emean, Emin) of the middle of left renal parenchyma, the values of Young′s modulus in the control group and DN patients were compared. The relationship between Young′s modulus and ACR in patients with DN was analyzed. Results The Emax, Emean and Emin in DN patients were all greater than those in control group (P<0.05). In group A, B and C, Emax, Emean and Emin gradually increased (P<0.05). Spearman correlation analysis showed that there was a positive correlation between Young′s modulus and ACR in patients with DN (r=0.817, 0.764, 0.609; all P=0.000). ROC curve analysis showed that the area under the curve of Emax diagnosis DN Ⅲ stage was 0.810, the cut-point value was 6.65 kPa, the sensitivity was 79.0%, and the specificity was 81.7%; the area under the curve of Emean diagnosis DN Ⅲ stage was 0.785, and the cut-off value was 3.69 kPa, sensitivity 62.8%, specificity 78.3%. Conclusions SWE technique can quantitatively analyze renal parenchyma hardness in patients with different stages of DN, which may provide new diagnostic information for early diagnosis of DN. Key words: Ultrasonography; Diabetic nephropathy; Shear-wave elastography; Renal parenchyma elasticity

Application of shear wave elastography combined with superb micro-vascular imaging in diagnosing benign and malignant thyroid masses

Objective To investigate the application value of shear wave elastography (SWE) combined with superb micro-vascular imaging (SMI) in differentiating malignant and benign thyroid masses. Methods Seventy-eight patients diagnosed by ultrasound and verified with postoperative pathological analysis were enrolled. Conventional two-dimensional ultrasound was applied to observe the masses. SWE was performed to evaluate the elasticity and the Young′s modulus (AveT1) value acquired. ROC curve was drawn to calculate the sensibility and specificity using the cut-off value of AveT1. SMI was applied to define Adler′s grading standard according to the degree of blood supply. The sensitivity, specificity and accuracy of SWE and SWE combined with SMI in differentiating malignant and benign thyroid masses were analyzed. Results ①According to pathological analysis, there were 42 benign and 44 malignant masses; ②The AveT1 value between malignant and benign groups were all significantly different (P<0.01). 41.4 kPa was used as the best cut-off value of AveT1. The area under the ROC curve were 0.83 with sensitivity 86.9% and specificity 88.1%; ③There were more masses with the Alder class Ⅱ-Ⅲ in malignant group than those in benign group, and the difference was statistically significant (P<0.01); ④Quantified with SWE or SWE combined with SMI, the sensitivity were 86.9% and 91.3%, specificity were 88.1% and 92.8%, and accuracy were 87.5% and 94.1%, respectively, and the difference was statistically significant (P<0.01). Conclusions SWE combined with SMI represents an excellent application value in differentiating malignant and benign thyroid masses, which could improve the sensitivity, specificity and accuracy of the diagnosis for thyroid masses using ultrasound. Key words: Real-time shear wave elastography; Superb micro-vascular imaging; Thyroid neoplasms

ELASTICITY MEASUREMENTS BY SHEAR WAVE ELASTOGRAPHY: COMPARISON AND SELECTION OF SHEAR WAVE, RAYLEIGH WAVE AND LAMB WAVE THEORY

Shear wave elastography (SWE) is a powerful method for the diagnosis of tissue disorders or degeneration based on tissue elasticity. In SWE application, it was recognized that the wave speed depends not only on the tissue elasticity but also on the structural shape, leading to different theoretical models. For liver, skin and myocardium, the appropriate theoretical model is known to be shear wave, Rayleigh wave and Lamb wave theory, respectively. Therefore, appropriate theoretical model should be adopted for the proper application of SWE. In this study, we verify these theoretical models in gelatin samples of different thicknesses, using experimental and numerical SWE tests. The results indicate that the wave speed was influenced by the ratio of the wavelength and sample thickness and the measurement region. Based on these results, the selection of theoretical model could be divided into three cases, and the appropriate theoretical model can be selected accordingly.

The assessment of the applicability of shear wave elastography in modelling of the mechanical parameters of the liver

The assessment of the applicability of shear wave elastography in modelling of the mechanical parameters of the liver

Current status of musculoskeletal application of shear wave elastography.

Ultrasonography (US) is a very powerful diagnostic modality for the musculoskeletal system due to the ability to perform real-time dynamic high-resolution examinations with the Doppler technique. In addition to acquiring morphologic data, we can now obtain biomechanical information by quantifying the elasticity of the musculoskeletal structures with US elastography. The earlier diagnosis of degeneration and the ability to perform follow-up evaluations of healing and the effects of treatment are possible. US elastography enables a transition from US-based inspection to US-based palpation in order to diagnose the characteristics of tissue. Shear wave elastography is considered the most suitable type of US elastography for the musculoskeletal system. It is widely used for tendons, ligaments, and muscles. It is important to understand practice guidelines in order to enhance reproducibility. Incorporating viscoelasticity and overcoming inconsistencies among manufacturers are future tasks for improving the capabilities of US elastography.

Application of shear wave elastography for the gastrocnemius medial head to tennis leg.

Muscle strain of the gastrocnemius medial head mainly occurs at the musculotendinous junction (MTJ), and stiffness is a risk factor. Shear wave elastography (SWE) measures elasticity by determining the propagation velocity. The aim of this study was to measure the elasticity of the normal muscle and aponeurosis in the MTJ of the gastrocnemius medial head using SWE, thus obtaining information relevant to muscle strain at this point. Forty-one volunteers (82 legs) were recruited and the gastrocnemius medial heads were examined at four points: three on the aponeurosis, namely at the center of the MTJ (Central), 10 mm proximal to it (Proximal) and 10 mm distal to it (Distal); and at one on the muscle belly (Muscle). The measurements were compared among the points, between males and females, and between younger and middle-aged subjects. Correlations between the elastic modulus and age were also examined. The elastic moduli at Proximal, Central, Distal, and Muscle were 2.82 ± 0.53 m/s, 3.43 ± 0.83 m/s, 4.83 ± 1.56 m/s, and 2.25 ± 0.43 m/s, respectively. These values differed significantly among the points of the aponeurosis, Distal having the highest modulus followed by Central. The elastic moduli were significantly greater in males than females at Distal and Muscle and in younger subjects than middle-aged subjects at Muscle. No significant correlations between elastic modulus and age were observed for any point. SWE could be a feasible method for quantifying the elasticity of muscle and aponeurosis in the MTJ of the gastrocnemius medial head. Clin. Anat. 30:114-119, 2017. © 2016 Wiley Periodicals, Inc.

Value of ultrasound shear wave elastography in the diagnosis of adenomyosis.

The aim of the study was to assess the accuracy of ultrasound shear wave elastography in the diagnosis of adenomyosis. One hundred and fifty three patients were examined. Ninety-seven patients were with suspected adenomyosis and 56 patients were with unremarkable myometrium. Adenomyosis was confirmed in 39 cases (A subgroup) and excluded in 14 cases (B subgroup) in the main group based on morphological examination. All patients underwent ultrasound examination using an Aixplorer (Supersonic Imagine, France) scanner with application of shear wave elastography during transvaginal scanning. Retrospective analysis of the elastography criteria against the findings from morphological/histological examination was performed. The following values of Young's modulus were found in subgroup A (adenomyosis): Emean - 72.7 (22.6-274.2) kPa (median, 5-95th percentiles), Emax - 94.8 (29.3-300.0) kPa, SD - 9.9 (2.6-26.3) kPa; in subgroup B (non adenomyosis) - 28.3 (12.7-59.5) kPa, 33.6 (16.0-80.8) kPa, 3.0 (1.4-15.6) kPa; in the control group - 24.4 (17.9-32.4) kPa, 29.8 (21.6-40.8) kPa, 2.3 (1.3-6.1) kPa, respectively (P < 0.05 for all comparison with subgroup В and the control group). The Emean cut-off value for adenomyosis diagnosis was 34.6 kPa. The sensitivity, specificity, positive predictive value, negative predictive value and area under curve (AUC) were 89.7%, 92.9%, 97.2%, 76.5% and 0.908. The Emax cut-off value was 45.4 kPa (89.7%, 92.9%, 97.2%, 76.5% and 0.907, respectively). This study showed a significant increase of the myometrial stiffness estimated with shear wave elastography use in patients with adenomyosis.

Application of shear wave elastography combined with superb micro-vascular imaging in diagnosing benign and malignant breast solid masses

Objective To investigate the application value of shear wave elastography (SWE) combined with superb micro-vascular imaging (SMI) in differentiating malignant and benign breast masses. Methods Seventy-two patients diagnosed by ultrasound and verified with postoperative pathological analysis were selected. There were total 86 masses including 42 benign and 44 malignant masses. After two-dimensional ultrasonography, SWE and SMI were performed to evaluate the elasticity and micro-vascular status in breast masses. ROC curve was drawn to calculate the sensibility and specificity. SMI was used as the reference to calculate the sensitivity and specificity of SWE combined with SMI in differentiating malignant and benign breast masses. Results ①There was no significant difference in the maximum diameter between two groups. ②The Young′s modulus (AveT1), the ratio between fat and mass (Ratio1) and SMI values between malignant and benign groups were all significantly different (P<0.01). ③The 56.75 kPa was used as the best cut-off value of AveT1, the area under the ROC curve was 0.917 with sensitivity 81.8% and specificity 85.7%. ④The 4.13 was used as the best cut-off value of Ratio1, the area under the ROC curve was 0.819 with sensitivity 90.9% and specificity 77.7%. ⑤SWE combined with SMI reduced the misdiagnosis rate from 9.52% of SWE only to 4.76% with sensitivity 93.18% and specificity 92.23%. Conclusions SWE combined with SMI represents excellent application value in differentiating malignant and benign breast masses, which can reduce the misdiagnosis rate effectively and promote the sensitivity and specificity of diagnosis. Key words: Elasticity imaging techniques; Breast neoplasms; Shear wave elastography; Superb micro-vascular imaging

Clinical Application of Shear Wave Elastography in Breast Masses

Background: Quantitative shear wave elastography (SWE) has been developed and utilized to aid in the differentiation between benign and malignant breast lesions based on their stiffness. Objectives: The purpose of this study was to evaluate the clinical effects of the additional use of SWE to conventional ultrasound (US) according to the maximum (Emax) and mean (Emean) elasticitiy values. Patients and Methods: A total 115 patients with 133 lesions were assessed using conventional US and SWE. All patients underwent US-guided core needle biopsy or surgery, and the pathological results were used as reference standards. We compared the diagnostic values including sensitivities, specificities, positive predictive values (PPVs) and negative predictive values (NPVs) and accuracies of conventional US and SWE according to the Emax and Emean values. Next, we obtained the optimal Emax and Emean cutoff values for SWE. Using these cutoff values, we analyzed the clinical effects of the additional use of SWE to conventional US based on the corrected results. Results: Of the 133 breast lesions, 32 were malignant and 101 were benign. In the differentiation of benign and malignant lesions, conventional US resulted in sensitivity of 100 %, specificity of 43.0 %, PPV of 57.1 %, NPV of 36.7 %, and accuracy of 100 %. Regarding SWE, the sensitivity, specificity, PPV, NPV, and accuracy values based on Emax were 84.4 %, 89.1 %, 71.1 %, 94.7 %, and 88.0 %, respectively, and the corresponding values based on Emean were 84.8 %, 93.0 %, 91.0 %, 80.0 %, and 94.9 %, respectively. The optimal Emax and Emean cutoff values were 81.3 and 60.7 kPa, respectively. However, there was no significant difference between Emax and Emean. The corrected results related to the additional use of SWE to conventional US indicated 97.0 % sensitivity, 93.0 % specificity, 82.1 % PPV, 98.9 % NPV, and 94.0 % accuracy (P < 0.0001). Conclusion: The additional use of SWE to conventional US resulted in marked improvements in specificity, PPV, and accuracy and slight diminutions in sensitivity and NPV for the differentiation benign and malignant breast lesions. Both Emax and Emean were effective diagnostic parameters, and there was no significant difference between these two parameters.

Bias of shear wave elasticity measurements in thin layer samples and a simple correction strategy.

Shear wave elastography (SWE) is an emerging technique for measuring biological tissue stiffness. However, the application of SWE in thin layer tissues is limited by bias due to the influence of geometry on measured shear wave speed. In this study, we investigated the bias of Young’s modulus measured by SWE in thin layer gelatin–agar phantoms, and compared the result with finite element method and Lamb wave model simulation. The result indicated that the Young’s modulus measured by SWE decreased continuously when the sample thickness decreased, and this effect was more significant for smaller thickness. We proposed a new empirical formula which can conveniently correct the bias without the need of using complicated mathematical modeling. In summary, we confirmed the nonlinear relation between thickness and Young’s modulus measured by SWE in thin layer samples, and offered a simple and practical correction strategy which is convenient for clinicians to use.

The role of shear wave elastography in the diagnosis of chronic autoimmune thyroiditis.

The aim of this study is to assess the applicability of shear wave elastography (SWE) in the diagnosis of chronic autoimmune thyroiditis (CAT) patients. The study group consisted of 50 patients with first-diagnosed CAT and 40 control subjects (CS). In all patients with CAT and CS, sonoelastographic measurements were made in both thyroid lobes. Optimal cut-off values were chosen to maximize the sum of sensitivity and specificity. Positive predictive value (PPV), negative predictive value (NPV), and accuracy values were also calculated. Quantitative elastographic analysis evaluated by SWE in CAT patients (2.56 +/- 0.30 m/s) was significantly higher compared with CS (1.63 +/- 0.12 m/s) (p<0.001). The optimal cut-off value was 2.42 m/s. SWE had 77% sensitivity, 71% specificity, 92% PPV, 81% NPV, and 87% accuracy for the presence of CAT. Our data indicate that SWE correctly defines the elasticity of thyroid parenchyma, and this technique may assist in the diagnosis and treatment monitoring of CAT.

Applicability of Shear Wave Elastography of the Major Salivary Glands: Values in Healthy Patients and Effects of Gender, Smoking and Pre-Compression

Our aim in this study was to determine normal shear wave elastography (SWE) values for the parenchyma of the major salivary glands and to evaluate the influences of gender, smoking, side and type of gland and varying amounts of ultrasound probe pressure on SWE values. Twenty-five consecutive healthy patients were examined with ultrasound. SWE velocities were measured with acoustic radiation force imaging in the hilum and central region of both glands with “normal” and very low pressure. Mean SWE velocities were 1.854 m/s for the parotid gland and 1.932 m/s for the submandibular gland. No statistically significant differences were detected between males and females, smokers and non-smokers, parotid and submandibular gland and left and right sides. Greater pre-compression with the ultrasound probe resulted in a statistically significant increase in the SWE values of both salivary glands (p < 0.000). The degree of pre-compression by the ultrasound transducer should be standardized, so that the reliability and reproducibility of this innovative method can be improved.

What are the characteristics of breast cancers misclassified as benign by quantitative ultrasound shear wave elastography?

Shear wave elastography (SWE) is a promising adjunct to greyscale ultrasound in differentiating benign from malignant breast masses. The purpose of this study was to characterise breast cancers which are not stiff on quantitative SWE, to elucidate potential sources of error in clinical application of SWE to evaluation of breast masses. Three hundred and two consecutive patients examined by SWE who underwent immediate surgery for breast cancer were included. Characteristics of 280 lesions with suspicious SWE values (mean stiffness >50 kPa) were compared with 22 lesions with benign SWE values (<50 kPa). Statistical significance of the differences was assessed using non-parametric goodness-of-fit tests. Pure ductal carcinoma in situ (DCIS) masses were more often soft on SWE than masses representing invasive breast cancer. Invasive cancers that were soft were more frequently: histological grade 1, tubular subtype, ≤10mm invasive size and detected at screening mammography. No significant differences were found with respect to the presence of invasive lobular cancer, vascular invasion, hormone and HER-2 receptor status. Lymph node positivity was less common in soft cancers. Malignant breast masses classified as benign by quantitative SWE tend to have better prognostic features than those correctly classified as malignant. • Over 90 % of cancers assessable with ultrasound have a mean stiffness >50 kPa. • 'Soft' invasive cancers are frequently small (≤10mm), low grade and screen-detected. • Pure DCIS masses are more often soft than invasive cancers (>40 %). • Large symptomatic masses are better evaluated with SWE than small clinically occult lesions. • When assessing small lesions, 'softness' should not raise the threshold for biopsy.

A review of the medical applications of shear wave elastography

Supersonic shear wave elastography (SWE) is a quantitative stiffness imaging technique based on the combination of a radiation force induced in tissue by an ultrasonic beam and ultrafast ultrasound imaging sequence (up to more than 10,000 frames per second) catching in real time the propagation of the resulting shear waves. Local shear wave speed is estimated and enables the two dimensional mapping of shear elasticity. This imaging modality is implemented on conventional probes driven by dedicated ultrafast echographic devices and can be performed during a standard ultrasound exam. The clinical potential of SSI is today extensively investigated for many potential applications such as breast cancer diagnosis, liver fibrosis staging, cardiovascular applications, and ophthalmology. This invited lecture will present an overview of the current investigated applications of SSI and the new trends of shear wave elastography research topics.

Primary application of shear wave elastography in diagnosis of prostate cancer

Objective To explore the value of shear wave elastrography (SWE) in diagnosis of prostate cancer.Methods SWE quantitative elastography was preformed in 55 patients with suspected prostate cancer,to obtain the elastic modulus (mean,maximum).Each patient underwent sonography-guided prostatic biopsy on the same day.With the pathologic results as reference,ROC curves were used to assess diagnostic performance.Results ①Pathological tests showed that 39 lesions were benign(hyperplasia) and 16 lesions were malignant.The mean elasticity value of benign lesions was (39.04 ± 8.22) kPa,and the maximum value was (54.10 ± 9.18)kPa,whereas of malignant ones were (53.31 ± 3.92)kPa and (68.71 ±2.57)kPa,respectively (P ＜0.05).② The area under the ROC curve (AZ) of the maximum and mean elasticity value was 0.951 and 0.944.Taking 48.07 kPa as the threshold of the mean elasticity value,the sensitivity was 91.8％ and the specificity was 89.7％.Then taking 65.50 kPa as the threshold of the maximum elasticity value,the sensitivity was 92.1％ and the specificity was 87.5％.Conclusions SWE is helpful to diagnose and differentiate prostate diseases by measuring elastic modulus. Key words: Ultrasonography; Prostatic neoplasms; Elastography

The first experience of application of shear wave elastography of the common carotid artery

The first experience of application of shear wave elastography of the common carotid artery

Application of shear wave elastography in the diagnosis of mammary gland neoplasm in dogs

The aim of the study was to evaluate the usefulness of elastography in the differential diagnosis of benign and malignant tumours of the mammary gland in dogs. The study was performed to 12 female dogs of different breeds aged 5-12 years in which tumoral lesions of the mammary gland were found in the clinical examination. In all the animals elastographic examination of the lesions was carried out and then the fine-needle aspiration biopsy was performed to determine the nature and degree of malignancy of the lesions. The examinations proved that benign neoplasms of the mammary gland showed low stiffness (average 22.42 kPa, range 19 to 42.4 kPa), whereas malignant neoplasms were characterized by high stiffness (average 235.44 kPa, range 171 to 300 kPa). On the basis of the results obtained we conclude that the elastography of proliferative lesions of the mammary gland is a useful diagnostic method for distinguishing benign neoplastic lesions from malignant neoplasms.

Shear Wave Elastography of the Common Carotid Artery: The First Experience of Application

Shear wave elastography (SWE) - a new technology, which in addition to ultrasound imaging provides quantitative information about tissue elasticity. Application of SWE in the study of vessels has not been studied. The purpose of this study is to assess the possibility of SWE in the investigations of the carotid arteries and to evaluate a reproducibility of quantitative measurement of elasticity of the carotid arteries by this method.

Liver fibrosis evaluation using real-time shear wave elastography: Applicability and diagnostic performance using methods without a gold standard

Real-time shear wave elastography (SWE) is a new two-dimensional transient elastography which had no assessment of factors associated with reliability, and had limited comparisons with other validated fibrosis biomarkers. The aim was to assess the applicability and performances of SWE for the diagnosis of fibrosis as compared with FibroTest (FT) and liver stiffness measurement (LSM) by transient elastography using two probes (TE-M and TE-XL). Without a gold standard, the strength of concordance, discordance analysis and latent class analysis (LCM) were applied. 422 patients were included. The applicability of SWE (90.0%) was significantly lower than that of FT (97.9%; p <0.0001) and did not differ from those of TE-M (90.5%) and TE-XL (90.3%); it was higher though for SWE (86%) in 22 patients with ascites vs. 55% using TE-M (p=0.04). For the diagnosis of all fibrosis stages as presumed by FT, the performance of SWE was highly significant (Obuchowski measure 0.807 ± 0.013 [m ± se]), but lower than those of TE-M (0.852; p=0.0007) and TE-XL (0.834; p=0.046). SWE had a low performance for discrimination between F0 and F1. For the diagnosis of cirrhosis using LCM, SWE specificities were all equal to 99%, and SWE sensitivities ranged from 0.47 to 0.64. For the diagnosis of non-cirrhotic stages, the results were heterogeneous. The performance of SWE for the diagnosis of cirrhosis was similar to those of FT and TE. SWE applicability was lower than that of FT, but greater than that of TE in patients with ascites.