Dr Kathy Schilling, Christine E. Lynn Women’s Health & Wellness Institute, Boca Raton Regional Hospital, Boca Raton, Florida, USA.
Echocardiography in Pediatric and Congenital Heart Disease: From Fetus to Adult, 2nd Ed. Edited by W. W. Lai, L. L. Mertens, M. S. Cohen, T. Geva ; Feb 2016, pp 86-88
At a busy breast imaging facility in Florida the advanced ultrasound technique, ShearWave Elastography (SWE) has altered the way women are cared for both for benign and suspicious findings. SWE has reduced the number of benign lesions mistakenly flagged for biopsy, significantly decreasing the false positive rate of ultrasound. The technique has also helped reduce the initial level of false negative diagnoses in patients who ultimately are found to have breast cancer. This article describes the role ShearWave technology plays in the breast imaging center and gives examples of cases in which it assists in refining the ultrasound diagnosis.
Major Advantages of SWE: A major advantage of SWE is that the results are not dependent on the expertise of the operator, neither when the results are generated from individual scans nor from scans of the same patient by different operators or at different times. In practice, the system’s color mapping capability has become an important tool for the training of the technologists in our facility. Through the morphologic assessment of a specific lesion the likelihood of malignancy can be assessed. When a benign lesion is suspected morphologically, the amount of transducer pressure on the breast can be varied to result in the appearance of a benign lesion.
Clinical Advantages of SWE: ShearWave Elastography improves the management of the breast cancer patient; the examinations are accurate and reproducible. In a study of 1800 patients using the Aixplorer system the results clearly showed that SWE helps reduce negative biopsies. In fact the PPV3 of lesions evaluated by SWE and BIRADS morphology characteristics together as compared to BI-RADS alone increased from 52.6% to 67.1% with a p <0.001. In addition, by adding SWE parameters to BIRADS assessment of sonographic lesions, approximately 90% of BI-RADS 4a lesions could be downgraded to BIRADS 3, thereby avoiding an unnecessary invasive procedure. Elastography also has prognostic potential as increased stiffness is found in tumors of higher grade, of larger size and with a greater likelihood of lymphovascular invasion and nodal involvement. The stiffer tumors are also more likely to be HER2+ and triple negative. The series of cases illustrated in this article show some of the clinical applications and resulting benefits of real-time, quantified and color-mapped SWE.
Conclusions: In our facility, ShearWave Elastography has significantly improved the quality of care and overall diagnostic performance of our physicians when breast ultrasound is performed. The technique gives us the ability to reliably downgrade a sonographic lesion from one of low suspicion requiring biopsy (BI-RADS 4a) to one of low suspicion not requiring biopsy (BI-RADS 2 or 3). This has resulted in our recommendation of whole breast ultrasound in patients with elevated risk or breast density in order to achieve supplemental cancer detection above that detected with mammography alone. Additionally, with the information provided by SWE, we are able to better triage patients requiring biopsy, prioritizing those most likely to harbor a malignancy thus enabling swift diagnosis and treatment.
WFUMB GUIDELINES AND RECOMMENDATIONS FOR CLINICAL USE OF ULTRASOUND ELASTOGRAPHY: PART 3: LIVER
The World Federation for Ultrasound in Medicine and Biology (WFUMB) has produced these guidelines for the use of elastography techniques in liver disease. For each available technique, the reproducibility, results, and limitations are analyzed, and recommendations are given. Finally, recommendations based on the international literature and the findings of the WFUMB expert group are established as answers to common questions. The document has a clinical perspective and is aimed at assessing the usefulness of elastography in the management of liver diseases.
WFUMB GUIDELINES AND RECOMMENDATIONS FOR CLINICAL USE OF ULTRASOUND ELASTOGRAPHY: PART 2: BREAST
The breast section of these Guidelines and Recommendations for Elastography produced under the auspices of the World Federation of Ultrasound in Medicine and Biology (WFUMB) assesses the clinically used applications of all forms of elastography used in breast imaging. The literature on various breast elastography techniques is reviewed, and recommendations are made on evidence-based results. Practical advice is given on how to perform and interpret breast elastography for optimal results, with emphasis placed on avoiding pitfalls. Artifacts are reviewed, and the clinical utility of some artifacts is discussed. Both strain and shear wave techniques have been shown to be highly accurate in characterizing breast lesions as benign or malignant. The relationship between the various techniques is discussed, and recommended interpretation based on a BI-RADS-like malignancy probability scale is provided. This document is intended to be used as a reference and to guide clinical users in a practical way.
ПРЕСС-РЕЛИЗ: Доказанные преимущества эластографии ShearWaveTM: журналы Radiology и European Radiology сообщают о высокой воспроизводимости и значительном улучшении специфичности УЗИ - www.interfax-russia.ru
Objectives: The purpose of this study was to assess the performance of shear wave elastography for identification of benign and malignant thyroid nodules using meta- analysis.
Methods: PubMed, MEDLINE, Embase, the Cochrane Library, and the China National Knowledge Infrastructure were searched. Patients’ clinical characteristics, sensitivity, specificity, positive predictive value, and negative predictive value were extracted. The diagnostic odds ratio and summary receiver operating characteristic curve were used to examine the accuracy of shear wave elastography. A meta-analysis was performed to evaluate the clinical utility of shear wave elastography for identification of benign and malignant thyroid nodules.
Results: The summary sensitivity and specificity for the diagnosis of malignant thyroid nodules by shear wave elastography were 0.84 (95% confidence interval [CI], 0.76–0.90) and 0.90 (95% CI, 0.87–0.92), respectively. The pooled positive likelihood ratio was 7.39 (95% CI, 4.09–13.35), and the negative likelihood ratio was 0.20 (95% CI, 0.13– 0.29). The summary diagnostic odds ratio was 41.35 (95% CI, 17.38–98.41), and the summary area under the receiver operating characteristic curve was 0.92 (Q* = 0.8538).
Conclusions: Shear wave elastography has high sensitivity and specificity in the evaluation of thyroid nodules and can potentially reduce unnecessary fine-needle aspiration biopsies.
Comparison of Diagnostic Value of Conventional Ultrasonography and Shear Wave Elastography in the Prediction of Thyroid Lesions Malignancy
Ewelina Szczepanek-Parulska, Kosma Woliński, Adam Stangierski, Edyta Gurgul, Maciej Biczysko, Przemysław Majewski, Magdalena Rewaj-Łosyk, Marek Ruchała
PLoS ONE, November 2013, Volume 8, Issue 11, e81532
Introduction: Thyroid nodular disease (TND) is a very common disorder. However, since the rate of malignancy is reported to be 3-10%, only a minority of patients require aggressive surgical treatment. As a result, there is a need for diagnostic tools which would allow for a reliable differentiation between benign and malignant nodules. Although a number of conventional ultrasonographic (US) features are proved to be markers of malignancy, Shear Wave Elastography (SWE) is considered to be an improvement of conventional US. The aim of this study was to compare conventional US markers and SWE diagnostic values in the differentiation of benign and malignant thyroid nodules.
Materials and Methods: All patients referred for thyroidectomy, irrespective of the indications, underwent a US thyroid examination prospectively. Patients with TND were included into the study. Results of the US and SWE examinations were compared with post-surgical histopathology.
Results: One hundred and twenty two patients with 393 thyroid nodules were included into the study. Twenty two patients were diagnosed with cancer. SWE turned out to be a predictor of malignancy superior to any other conventional US markers (OR=54.5 using qualitative scales and 40.8 using quantitative data on maximal stiffness with a threshold of 50 kPa).
Conclusions: Although most conventional US markers of malignancy prove to be significant, none of them are characterized by both high sensitivity and specificity. SWE seems to be an important step forward, allowing for a more reliable distinction of benign and malignant thyroid nodules. Our study, assessing SWE properties on the highest number of thyroid lesions at the time of publication, confirms the high diagnostic value of this technique. It also indicates that a quantitative evaluation of thyroid lesions is not superior to simpler qualitative methods.
Diagnostic role of conventional ultrasonography and shearwave elastography in asymptomatic patients with diffuse thyroid disease: initial experience with 57 patients
Injoong Kim, Eun-Kyung Kim, Jung Hyun Yoon, Kyung Hwa Han, Eun Ju Son, Hee Jung Moon, and Jin Young Kwak
Yonsei Med J 55(1):247-253, 2014
Purpose: Thyroid ultrasonography (US) is a useful diagnostic tool in the evaluation of diffuse thyroid disease (DTD), whereas shearwave elastography is a dynamic technique that can provide information about tissue hardness by using acoustic shearwaves remotely induced by a focused ultrasonic beam. This study aims at investigating the role of conventional US and shearwave elastography in the diagnosis of asymptomatic patients with DTD.
Materials and Methods: Fifty-seven patients who underwent both conventional US and shearwave elastography were included in this study. Interobserver variability of the three radiologists in assessment of underlying thyroid echogenicity on conventional US was analyzed. Diagnostic performances for diagnosing DTD on conventional US and shearwave elastography were calculated and compared.
Results: Fair agreement was observed in the identification of DTD with conventional US (kappa value=0.27). The area under the receiver operating characteristic curve (Az) were 0.52- 0.585 on conventional US by three radiologists. The Az values when using the mean and maximum elasticity values as a diagnostic criteria for DTD were 0.619 and 0.59 on shearwave elastography. Patients with DTD showed higher mean [24.1±10 kilo-Pascals (kPa)] and maximum (36.4±13.3 kPa) elasticity values on shearwave elastography when compared to the normal group (23.4±10.8 kPa and 33.7±12.4 kPa, respectively), although without statistical significance (p=0.802 and p=0.452, respectively).
Conclusion: Conventional US did not show reliable interobserver agreement in the diagnosis of DTD. Although not statistically significant, shearwave elastography may provide additional information in the diagnosis of DTD. Therefore, larger prospective studies are needed to define the values of shearwave elastography for diagnosing DTD.
[ ongoing research ] Development and assessment of novel ultrasound techniques for assessment of unstable carotid plaque
KV Ramnarine, S Nduwayo, B Kanber, K Dexter, TC Hartshorne, D Moore, K West, RB Panerai, AR Naylor and TG Robinson
Medical Physics Department, University Hospitals of Leicester NHS Trust
Department of Vascular and Endovascular Surgery, University Hospitals of Leicester NHS Trust
Department of Histopathology, University Hospitals of Leicester NHS Trust
Department of Cardiovascular Sciences, University of Leicester
DESCRIPTION FROM THE RESEARCH WEBSITE
The current selection process for deciding which patients will undergo carotid endarterectomy surgery is heavily reliant on ultrasound measurement of blood flow velocity. This is used as a surrogate measure of lumen diameter reduction (stenosis). The degree of stenosis however is a poor predictor of individual stroke risk, hence the search for diverse markers (e.g. biological, chemical, imaging) of plaque instability is essential to improve risk stratification models for stroke.
Our research is focussed on the application of novel ultrasound imaging techniques to assess the biomechanical properties and dynamic behaviour of plaque. We have a state of the art Supersonic Imagine Aixplorer ultrasound system that utilises ShearWave Elastography for assessment of tissue stiffness. Our studies have evaluated the clinical feasibility of ShearWave Elastography for imaging the carotid plaque and assessed the performance in-vitro and in-vivo. We are also quantifying parameters that describe the dynamic behaviour of plaque to help identify the unstable plaque.
Acknowledgements: This work has been funded in part by The National Institute for Health Research Collaboration for Leadership in Applied Health Research and Care - Leicestershire, Northamptonshire and Rutland (NIHR CLAHRC for LNR).
Which are the cut-off values of 2D-Shear Wave Elastography (2D-SWE) liver stiffness measurements predicting different stages of liver fibrosis, considering Transient Elastography (TE) as the reference method?
Ioan Sporea, Simona Bota, Oana Gradinaru-Taşcău, Roxana Şirli, Alina Popescu, Ana Jurchiş,
European Journal of Radiology, March 2014, Volume 83, Issue 3, Pages e118–e122
Introduction: To identify liver stiffness (LS) cut-off values assessed by means of 2D-Shear Wave Elastography (2D-SWE) for predicting different stages of liver fibrosis, considering Transient Elastography (TE) as the reference method.
Methods: Our prospective study included 383 consecutive subjects, with or without hepatopathies, in which LS was evaluated by means of TE and 2D-SWE. To discriminate between various stages of fibrosis by TE we used the following LS cut-offs (kPa): F1-6, F2-7.2, F3-9.6 and F4-14.5.
Results: The rate of reliable LS measurements was similar for TE and 2D-SWE: 73.9% vs. 79.9%, p = 0.06. Older age and higher BMI were associated for both TE and 2D-SWE with the impossibility to obtain reliable LS measurements. Reliable LS measurements by both elastographic methods were obtained in 65.2% of patients. A significant correlation was found between TE and 2D-SWE measurements (r = 0.68). The best LS cut-off values assessed by 2D-SWE for predicting different stages of liver fibrosis were: F ≥ 1: >7.1 kPa (AUROC = 0.825); F ≥ 2: >7.8 kPa (AUROC = 0.859); F ≥ 3: >8 kPa (AUROC = 0.897) and for F = 4: >11.5 kPa (AUROC = 0.914).
Conclusions: 2D-SWE is a reliable method for the non-invasive evaluation of liver fibrosis, considering TE as the reference method. The accuracy of 2D-SWE measurements increased with the severity of liver fibrosis.
Does shear wave ultrasound independently predict axillary lymphnode metastasis in women with invasive breast cancer?
Andrew Evans , Petra Rauchhaus, Patsy Whelehan, Kim Thomson, Colin A. Purdie, Lee B. Jordan, Caroline O. Michie, Alastair Thompson, Sarah Vinnicombe
Breast Cancer Research and Treatment, January 2014, Volume 143, Issue 1, pp 153-157
Shear wave elastography (SWE) shows promise as an adjunct to greyscale ultrasound examination in assessing breast masses. In breast cancer, higher lesion stiffness on SWE has been shown to be associated with features of poor prognosis. The purpose of this study was to assess whether lesion stiffness at SWE is an independent predictor of lymph node involvement. Patients with invasive breast cancer treated by primary surgery, who had undergone SWE examination were eligible. Data were retrospectively analysed from 396 consecutive patients. The mean stiffness values were obtained using the Aixplorer® ultrasound machine from SuperSonic Imagine Ltd. Measurements were taken from a region of interest positioned over the stiffest part of the abnormality. The average of the mean stiffness value obtained from each of two orthogonal image planes was used for analysis. Associations between lymph node involvement and mean lesion stiffness, invasive cancer size, histologic grade, tumour type, ER expression, HER-2 status and vascular invasion were assessed using univariate and multivariate logistic regression. At univariate analysis, invasive size, histologic grade, HER-2 status, vascular invasion, tumour type and mean stiffness were significantly associated with nodal involvement. Nodal involvement rates ranged from 7 % for tumours with mean stiffness <50 kPa to 41 % for tumours with a mean stiffness of >150 kPa. At multivariate analysis, invasive size, tumour type, vascular invasion, and mean stiffness maintained independent significance. Mean stiffness at SWE is an independent predictor of lymph node metastasis and thus can confer prognostic information additional to that provided by conventional preoperative tumour assessment and staging.
Keywords: Breast cancer Prognosis Elastography Metastasis
Quantitative assessment of shear-wave ultrasound elastography in thyroid nodules: diagnostic performance for predicting malignancy
Hana Kim, Jeong-Ah Kim, Eun Ju Son, Ji Hyun Youk
European Radiology, September 2013, Volume 23, Issue 9, pp 2532-2537
Objectives: To evaluate the predictability of shear-wave ultrasound elastography (SWE) for thyroid malignancy and to compare the diagnostic performances of SWE and B-mode US.
Methods: Retrospective review of 99 patients who underwent SWE before US-guided fine-needle aspiration of thyroid nodules was performed. SWE elasticity indices of the mean (Emean ), maximum (Emax), and minimum (Emin) of nodules were measured. Diagnostic performance of SWE was compared with that of B-mode US.
Results: Among a total of 99 nodules, 21 were papillary thyroid carcinoma (PTC) and 78 were benign. Emean, Emax, and Emin were significantly higher in PTCs than in benign nodules (P < 0.001). Sensitivity and specificity for predicting malignancy were 76.1 %, 64.1 % with Emax (65 kPa), 61.9 %, 76.1 % with Emin (53 kPa), and 66.6 %, 71.6 % with Emean (62 kPa). Areas under the ROC curves (Az) of SWE values were not significantly different from those of US categories on B-mode US. However, combining Emean and Emin with B-mode US of probably benign lesions improved the specificity (P = 0.02, 0.007) for predicting PTC.
Conclusions: The quantitative parameter of SWE was significantly higher in PTC than in benign nodules, and combined use of quantitative SWE and B-mode US provided higher specificity for predicting malignancy.
Quantitative shear-wave elastography (SWE) helps differentiate benign from malignant nodules
SWE and conventional ultrasound have comparable diagnostic performance for predicting thyroid malignancy
Combined quantitative SWE and B-mode ultrasound is highly specific for thyroid malignancy
How many measurements are needed for liver stiffness assessment by 2D-Shear Wave Elastography (2D-SWE) and which value should be used: the mean or median?
Ioan Sporea, Oana Gradinaru-Tascau, Simona Bota, Alina Popescu, Roxana Sirli, Ana Jurchis, Madalina Popescu
Medical Ultrasonography, December 2013, volume 15, number 4
Aim: To analyze how many measurements are needed for non-invasive assessment of liver stiffness (LS) by means of 2DShear Wave Elastography (2D-SWE) and if the use of mean of median values of 2D-SWE measurements is needed. Methods: We evaluated 449 consecutive subjects (with or without chronic liver disease) by means of Transient Elastography (TE) and 2D-SWE. We compared the correlation of LS assessed by TE with 2D-SWE measurements when using either the median of 5 valid 2D-SWE measurements or the mean of 3 or 5 valid 2D-SWE measurements. Results: We obtained reliable LS measurements by TE in 330/449 subjects (73.5%). From these, in 281 subjects we obtained 5 valid 2D-SWE measurements. The correlation of LS assessed by TE with 2D-SWE values was similar when we used the median value of 5 valid 2D-SWE measurements, the mean value of 5 valid 2D-SWE measurements or the mean value of 3 valid 2D-SWE measurements: r =0.683, r=0.711 and r=0.691, respectively. There were no significant differences between the median value of 5 valid 2D-SWE measurements; the mean value of 5 valid 2D-SWE measurements; or the mean value of 3 valid 2D-SWE measurements: 7.6 kPa, 7.7 kPa and 7.6 kPa, respectively. Conclusions: Our study showed that it is enough to perform 3 valid 2D-SWE measurements and to use the mean value of these measurements.
January 2nd, 2014 - A non invasive technique visualizes and quantitatively measures tissue stiffness across the different stages of fibrosis leading up to cirrhosis.
The Aixplorer Ultrasound System with ShearWave Elastography (SWE) can help determine quantitative liver stiffness values in an easy-to-use manner, which can be safely repeated over time to follow disease progression or regression.