Qualitative pattern classification of shear wave elastography for breast masses: How it correlates to quantitative measurements

Usefulness of Shear Wave Elastography in Determining the Tumor Extent of Basal Cell Carcinomas

OBJECTIVES

The purpose of this study was to investigate the value of shear wave elastography (SWE) in determining tumor extent of basal cell carcinomas (BCC), and thereby determine the optimal surgical margins (OSM).

METHODS

10 patients (40 surgical margins) with BCC were collected, the visual observation boundaries (VOB) were marked, and the SWE parameters of soft tissues were measured 1 mm intervals in "3, 6, 9, 12" clock directions, starting from VOB. Then tumors were resected with a 5 mm surgical margin outward expansion of VOB. All specimens were examined pathologically 1 mm intervals from VOB in four clock directions. With the positive margins furthest from the tumor as the real tumor boundaries (RTB) and the negative margins closest to the tumor as the optimal surgical margins (OSM). The SWE parameters were compared between these two groups.

RESULTS

The elasticity ratio (E_ratio ) of average young's modulus between region of interest and adjacent normal soft tissue had statistically significant differences between groups (P = .000), while other parameters show no difference. The E_ratio of RTB and OSM were 1.22 ± 0.14 and 0.99 ± 0.07. The area under the ROC curve was .947. Taking 1.075 as the threshold of E_ratio for the diagnosis of tumor extent, the sensitivity, specificity and accuracy were 87.5%, 90.0% and 90.0%. The surgical margins designed according to OSM were better than those designed according to VOB + 5 mm (P = .000).

CONCLUSIONS

The E_ratio of SWE is helpful in determining tumor extent of BCC. This is beneficial for surgical margin designing.

Quantitative Assessment of Breast-Tumor Stiffness Using Shear-Wave Elastography Histograms

Purpose: Shear-wave elastography (SWE) measures tissue elasticity using ultrasound waves. This study proposes a histogram-based SWE analysis to improve breast malignancy detection. Methods: N = 22/32 (patients/tumors) benign and n = 51/64 malignant breast tumors with histological ground truth. Colored SWE heatmaps were adjusted to a 0−180 kPa scale. Normalized, 250-binned RGB histograms were used as image descriptors based on skewness and area under curve (AUC). The histogram method was compared to conventional SWE metrics, such as (1) the qualitative 5-point scale classification and (2) average stiffness (SWEavg)/maximal tumor stiffness (SWEmax) within the tumor B-mode boundaries. Results: The SWEavg and SWEmax did not discriminate malignant lesions in this database, p > 0.05, rank sum test. RGB histograms, however, differed between malignant and benign tumors, p < 0.001, Kolmogorov−Smirnoff test. The AUC analysis of histograms revealed the reduction of soft-tissue components as a significant SWE biomarker (p = 0.03, rank sum). The diagnostic accuracy of the suggested method is still low (Se = 0.30 for Se = 0.90) and a subject for improvement in future studies. Conclusions: Histogram-based SWE quantitation improved the diagnostic accuracy for malignancy compared to conventional average SWE metrics. The sensitivity is a subject for improvement in future studies.

Correlation of Yes-Associated Protein 1 with Stroma Type and Tumor Stiffness in Hormone-Receptor Positive Breast Cancer

Simple Summary

YAP1 is an oncogene that can be activated by matrix stiffness, as it can act as a mechanotransducer. So far, only in vitro studies regarding YAP1 activation and matrix stiffness are present. We confirmed the activation of YAP1 in breast cancer using human breast cancer tissue and immunohistochemistry. Tumor stiffness was quantified by shear-wave elastography. Nuclear localization of YAP1 showed correlation with tumor stiffness in hormone-receptor positive (HR+) breast cancer. Also, tumors with non-collagen-type stroma showed an association between YAP1 expression and tumor stiffness. YAP1 expression, along with tumor stiffness, may serve as a prognostic candidate in HR+ breast cancer.

Abstract

(1) Background: Yes-associated protein 1 (YAP1) is an oncogene activated under the dysregulated Hippo pathway. YAP1 is also a mechanotransducer that is activated by matrix stiffness. So far, there are no in vivo studies on YAP1 expression related to stiffness. We aimed to investigate the association between YAP1 activation and tumor stiffness in human breast cancer samples, using immunohistochemistry and shear-wave elastography (SWE). (2) Methods: We included 488 patients with treatment-naïve breast cancer. Tumor stiffness was measured and the mean, maximal, and minimal elasticity values and elasticity ratios were recorded. Nuclear YAP1 expression was evaluated by immunohistochemistry and tumor-infiltrating lymphocytes (TILs); tumor-stroma ratio (TSR) and stroma type of tumors were also evaluated. (3) Results: Tumor stiffness was higher in tumors with YAP1 positivity, low TILs, and high TSR and was correlated with nuclear YAP1 expression; this correlation was observed in hormone receptor positive (HR+) tumors, as well as in tumors with non-collagen-type stroma. (4) Conclusions: We confirmed the correlation between nuclear YAP1 expression and tumor stiffness, and nuclear YAP1 expression was deemed a prognostic candidate in HR+ tumors combined with SWE-measured tumor stiffness.

A scoping review of methods used in musculoskeletal soft tissue and nerve shear wave elastography studies

This scoping review of shear wave elastography (SWE) articles in musculoskeletal soft tissue and nerve research demonstrates methodological heterogeneity resulting from a lack of standardized data collection and reporting requirements. Seven literature databases were searched for original articles published in English from 2004-2020 that examine human skeletal muscles, tendons, and nerves in vivo. Although 5,868 records were initially identified, only 375 reports met inclusion criteria. Of the 375 articles, 260 examined 89 unique muscles, 94 examined 14 unique tendons, and 43 examined 8 unique nerves. Cohorts were often small (n = 11-20) and young (mean = 20-29 years), and participants were typically tested in the prone position. Regarding equipment, a variety of ultrasound systems (n = 11), ultrasound models (n = 18), and transducers (n = 19) were identified. Only 11% of articles contained information on the use of electromyography to confirm absence of muscle activity, and only 8% reported measurement depth. Since musculoskeletal soft tissue and nerve stiffness can vary significantly based on data collection methods, it is essential to standardize SWE collection and reporting procedures. This will allow SWE to serve as a valid and reproducible tool for assessing tissue pathology, disease progression, and response to intervention within a variety of musculoskeletal and nerve-related disorders.

The Role of Superb Microvascular Imaging and Shearwave Elastography in the Evaluation of Intraductal Papilloma-Like Lesions

OBJECTIVES

The aim of this study was to investigate the role of quantitative values obtained by superb microvascular imaging (SMI) and shearwave elastography (SWE) in the prediction of malignancy in intraductal papilloma-like lesions (IDPL).

METHODS

In the study, 61 patients between the ages of 14 to 73 years (mean age 44) diagnosed with IDPL on ultrasound (US) examination between the years 2020 and 2021 were included. The B-Mode US findings (shape, margins, size, echo pattern, and accompanying ductal dilatation), SMI vascular index (SMIvi), E-mean, and SWE-ratio values were recorded.

RESULTS

There was a statistically significant difference between malignant (n = 14) and benign (n = 47) groups in terms of symptoms (P = .005), size (P = .042), shape (P = .002), margins (P =  .001), echogenicity (P = .023), microcalcifications (P = .009), SMIvi (P = .031), E-mean (P < .005), and SWE-ratio (P = .007). According to receiver operating characteristic (ROC) curve analysis, sensitivity, specificity, accuracy, area under the curve (AUC), positive predictive values (PPV), and negative predictive values (NPV) were 57.1%, 87.2%, 80%, 0.722, 57.1%, 87.2% for US; 71.4%, 49%, 55.7%, 0.692, 30.3%, 85.7% for SMIvi; 85.7%, 71%, 74%, 0.864, 46%, 94.3% for E-mean, and 50%, 75.4%, 83%, 0.707, 91.5%, and 50% for SWE-ratio, respectively. Best results were obtained when SMI and SWE values were used together, achieving a sensitivity, specificity, accuracy, AUC, PPD, NPD of 78.6%, 93.6%, 93.4%, 0.872, 91.7%, and 93.9%, respectively.

CONCLUSIONS

The SMI and SWE examinations are successful in the differentiation of benign and malignant intraductal lesions. They complement each other and contribute to B-mode US in managing IDPLs especially when used together. Our study is the first to compare the quantitative data of SWE and SMI in the differentiation of IDPLs.

The diagnostic accuracy of diffusion-weighted magnetic resonance imaging and shear wave elastography in comparison to dynamic contrast-enhanced MRI for diagnosing BIRADS 3 and 4 lesions

Background

Breast cancer is one of the leading causes of female morbidity and mortality. Management options vary between lesions of BIRADS categories 3 and 4. Therefore, reliable differentiation would improve outcome. Although sonomammography and contrast-enhanced breast magnetic resonance imaging (CE-MRI) remain the cornerstone for assessment of breast disease, additional, non-invasive techniques can be used to increase the efficiency of evaluation such as shear wave elastography (SWE) and diffusion-weighted magnetic resonance imaging (DW-MRI). This prospective study included 66 breast lesions that were categorized as BIRADS 3 or 4 by ultrasound ± mammography. All lesions were evaluated by SWE, CE-MRI and DW-MRI. For SWE, lesions were evaluated by both qualitative and quantitative methods. For CE-MRI, both morphological and kinematic evaluations were done and for DW-MRI, both qualitative and quantitative assessments were studied. Results of all imaging modalities were correlated to histopathology.

Results

Thirty-seven out of the examined 66 lesions (56.06%) were categorised as BIRADS 3, out of which 1 (2.7%) turned out to be malignant on histopathology and 36 (97.29%) were proved benign. Twenty-nine (43.93%) were categorized as BIRADS 4, out of which 2 (6.89%) turned out to be benign on pathology and 27 (93.1%) were proved malignant. Morphological and kinematic evaluations of CE-MRI showed 92.59% and 92.86%sensitivity, 94.74% and 84.21% specificity, 92.59 and 81.25%PPV, 94.74 and 94.12% NPV, and 93.85% and 87.88% accuracy respectively. Color-coded scoring of SWE showed indices of 89.29%, 68.42%, 67.57%, 89.66%, and 77.27% respectively. The calculated cut-off value for Emax differentiating benign from malignant was 65.15 kpa, resulting in indices of 96.43%, 57.89%, 95.65%, 62.79%, and 74.24% respectively. For Eratio, the calculated cut-off value was 4.55, resulting in indices of 71.43%, 68.42%, 76.47%, 62.50% and 69.70% respectively. For qualitative evaluation of DW-MRI, indices were 78.57%, 65.79%, 62.86%, 80.65%, and 71.21% respectively. For ADC, the calculated cut-off value was 1.25 × 103 mm2/s, which resulted in indices of 75.00%, 84.21%, 82.05%, 77.78%, and 80.30% respectively.

Conclusion

CE-MRI showed the best diagnostic performance indices. While, SWE and DW-MRI present variable diagnostic performance, both techniques can be used as an adjunct to other imaging modalities to aid the clinical decision and increase its diagnostic confidence.

Clinical Value of Shear Wave Elastography Color Scores in Classifying Thyroid Nodules

Objective

To evaluate the clinical value of qualitative shear wave elastography (SWE) color in the differential diagnosis of benign and malignant thyroid nodules.

Methods

From January 2017 to July 2018, 241 patients with 261 thyroid nodules, who underwent conventional ultrasonography and SWE examination before surgical resection, were enrolled. The nodules were also evaluated by histopathologic analyses. The SWE color characteristics that could differentiate malignant and benign thyroid nodules were selected and scored based on the malignancy rate. The diagnostic performances were evaluated by receiver operating characteristic (ROC) curves analysis.

Results

Among the 261 thyroid nodules, 58 were benign, and 203 were malignant. Malignancy was associated with orange or red as the color of maximum hardness inside a nodule, green as the primary color, with a “stiff rim,” inhomogeneous internal color, and inhomogeneous color between the nodules and its surrounding areas. The SWE color scores for benign thyroid nodules were mainly 0 and 1, while 4 and 5 were for malignant thyroid nodules. The area under the ROC curve (AUC) of the SWE color score ≥3 for the diagnosis of malignant thyroid nodules was 0.828 (95% CI: 0.764, 0.891) with a sensitivity of 82.8%, a specificity of 82.8%, and an accuracy of 83.1%. Additionally, conventional ultrasound combined with SWE color scores had a higher diagnostic performance than conventional ultrasound (AUC 0.820 vs AUC 0.796, P = 0.04).

Conclusion

The SWE color scores might be a convenient and effective method to assist in differentiating thyroid nodules.

Diagnostic Accuracy of Four Levels of Manual Compression Applied in Supersonic Shear Wave Elastography of the Breast

PURPOSE

To investigate the diagnostic accuracy of applying four levels of manual pressure in Shear Wave Elastography (SWE) of the breast and to assess inter-rater reliability.

MATERIALS AND METHODS

Single-center prospective preliminary study including patients receiving ultrasound examination of breast lesions as part of routine clinical practice. SWE was performed on 60 breast masses (26 benign and 34 malignant) in 54 patients by a breast fellowship trained radiologist. Stiffness values were compared between benign and malignant masses at four levels of manual compression: none, mild, moderate, and marked. Accuracy of SWE was assessed using receiving operating characteristics analysis at each level. In 18 patients, a second radiologist repeated the SWE acquisitions to evaluate reproducibility. Reproducibility was assessed using intraclass correlation coefficient.

RESULTS

Without compression, we observed no significant difference in stiffness (p > 0.99) between benign and malignant lesions, and SWE demonstrated low accuracy (area under the curve = 0.64). Stiffness was higher in malignant lesions at all levels of compression (p < 0.001). SWE demonstrated good accuracy at all three levels of compression (from area under the curve = 0.71 to 0.84 across Emax and Emean), with high interobserver agreement.

CONCLUSION

This preliminary study suggests that not using compression during SWE for breast lesion characterization offers suboptimal results. On the contrary, application of compression yields high diagnostic performance with good interobserver agreement and, as such, should be included in routine clinical practice.

Virtual touch imaging quantification shear-wave elastography for breast lesions: the diagnostic value of qualitative and quantitative features

AIM

To investigate the value of the qualitative and quantitative features of Virtual Touch imaging quantification (VTIQ) shear-wave elastography in the characterisation of breast lesions.

MATERIALS AND METHODS

Conventional ultrasound (US) and VTIQ were performed in 148 solid breast lesions in 148 women. During qualitative analysis, patterns of VTIQ were categorised into two patterns, 1 and 2. During quantitative analysis, the mean SWV (SWVmean) and the maximum SWV (SWVmax) of each lesion were used. The sensitivity, specificity, and the areas under the receiver operating characteristic (ROC) curve (Az value) were calculated for conventional US, VTIQ, and combined conventional US and VTIQ.

RESULTS

Malignant lesions were more likely to show VTIQ pattern 2 than the benign lesions (p<0.001). There was no significant difference in the Az values between SWVmean (0.907) and SWVmax (0.902; p=0.572). There was no significant difference in the Az values between the VTIQ pattern (0.884) and SWVmax (p=0.572). The combined conventional US and VTIQ pattern carried a similar Az value (0.949) as compared with the combined conventional US and SWVmax, which yielded an Az value of 0.952 (p=0.683).

CONCLUSION

The combination of either VTIQ pattern or SWVmax and conventional US may be helpful in the characterisation of benign and malignant breast lesions.

Multiparametric Ultrasound Examination in Tumor-Like Formations of the Ovaries

Properly diagnosed tumor-like formations of the ovaries facilitate the correct selection of patients who may not require surgery, or choose surgery with minimal access if such intervention is required. Subjective assessment of the features of tumor-like formations with the help of ultrasound diagnostics, including compression elastography, proved to be highly effective in the differential diagnosis of bulky ovarian formations. All tumor-like formations have their sonographic features that allow making a reliable diagnosis of a particular formation. The article reveals data on the diagnostic significance of multiparametric ultrasound imaging in the detection of ovarian tumor-like formations. A detailed sonographic picture of tumor-like formations in B-mode, color, and pulse Doppler mode and compression sonoelastography mode was analyzed. This examination was especially relevant for women of reproductive age, as it depended on the further tactics of treatment of each patient. For all types of tumor-like formations ovaries, a qualitative feature was determined - elastotype on the Ueno scale and the index of stiffness (Strain Ratio) - a quantitative indicator. Follicular cysts, endometrioid and periovarian cysts were found to belong to the 0 elastotype. Cysts of the corpus luteum belonged to the II elastotype on the Ueno scale. The lowest values of the stiffness index were seen in follicular and periovarian cysts, and the highest value was observed in endometrioid cysts. Our results have shown that ultrasound examination of ovarian tumors is an accurate and highly informative method.

Differentiating solid breast masses: comparison of the diagnostic efficacy of shear wave elastography and magnetic resonance imaging

OBJECTIVES

Shear wave elastography (SWE) quantitatively determines the nature of the breast lesions. Few previous studies have compared the diagnostic value of this modality with other imaging techniques. The present study aimed to compare the diagnostic value of SWE with that of magnetic resonance imaging (MRI) in detecting the nature of the breast masses.

METHODS

In this cross-sectional study, 80 patients with breast lumps who had Breast Imaging Reporting and Data System (BI-RADS) score of three or higher based on mammography and/or screening ultrasonography, underwent 3D SWE and MRI. The lesions were classified according to MRI BI-RADS scoring; Mean elasticity (Emean) and elasticity ratio (Eratio) for each lesion were also determined by SWE. The results of these two modalities were compared with histopathologic diagnosis as the gold standard method; diagnostic value and diagnostic agreement were then calculated.

RESULTS

Of the masses, 46.2% were histopathologically proven to be malignant. The Emean for benign and malignant masses was 34.04 ± 19.51 kPa and 161.92 ± 58.14 kPa, respectively. Both modalities had diagnostic agreement with histopathologic results (p<0.001). Kappa coefficient was 0.87 for SWE and 0.42 for MRI. The sensitivity of both methods was 94.59% (95% CI: 81.81-99.34), while the specificity and accuracy were 48.84% [95% CI: 33.31-64.54] and 70.0% [95% CI: 58.72-79.74] for MRI, and 93.02% [95% CI: 80.94-98.54] and 93.75% [95% CI: 86.01-97.94] for SWE.

CONCLUSIONS

SWE has better diagnostic value in terms of determining the nature of the breast masses. SWE can increase the diagnostic function of differentiating benign masses from malignant ones.

A Brief Review on Breast Carcinoma and Deliberation on Current Non Invasive Imaging Techniques for Detection

BACKGROUND

Breast carcinoma is a life threatening disease that accounts for 25.1% of all carcinoma among women worldwide. Early detection of the disease enhances the chance for survival.

DISCUSSION

This paper presents comprehensive report on breast carcinoma disease and its modalities available for detection and diagnosis, as it delves into the screening and detection modalities with special focus placed on the non-invasive techniques and its recent advancement work done, as well as a proposal on a novel method for the application of early breast carcinoma detection.

CONCLUSION

This paper aims to serve as a foundation guidance for the reader to attain bird's eye understanding on breast carcinoma disease and its current non-invasive modalities.

Qualitative Evaluation of Virtual Touch Imaging Quantification: A Simple and Useful Method in the Diagnosis of Breast Lesions

Objective

To test the value of qualitative virtual touch imaging quantification (VTIQ) features in differentiating benign from malignant breast lesions.

Methods

From November 2016 to August 2017, 230 lesions were subjected to conventional US and virtual touch imaging quantification before biopsy. The maximum shear wave velocity (SWVmax) was measured using a standardized method. Qualitative VTIQ features, including the “stiff rim” sign and color pattern classification, were assessed according to a binary classification. The sensitivity, specificity and area under the receiver operating curve (AUC) of Breast Imaging Reporting and Data System (BI-RADS), SWVmax, qualitative VTIQ features, and combined data were compared.

Results

Among the 230 breast lesions, 150 were benign and 80 were malignant. Compared to the benign lesions, the malignant ones had higher SWVmax values and were more likely to show the “stiff rim” sign and VTIQ pattern 2 (P <0.001 for all). The AUC value was 0.885 for the qualitative VTIQ combination (the presence of the “stiff rim” sign and/or the display of VTIQ pattern 2), similar to that for SWVmax (P=0.472). BI-RADS combined with the qualitative VTIQ combination and with SWVmax yielded similar results, including significantly higher AUC values (P = 0.018 and 0.014, respectively), significantly higher specificities (P<0.001 for both), and nonsignificantly decreased sensitivities (P = 0.249 for both) compared to BI-RADS alone.

Conclusion

The dual-category classification of qualitative VTIQ features according to the presence of the “stiff rim” sign and/or the classification of VTIQ pattern 2 is a simple and useful method that may be representative of quantitative VTIQ parameters in the evaluation of breast masses.

Shear Wave Elastography versus Strain Elastography in Diagnosing Parathyroid Adenomas

OBJECTIVES

The aim of the study was to compare elastographic means in parathyroid adenomas, using shear wave elastography and strain elastography.

METHODS

This prospective study examined 20 consecutive patients diagnosed with primary hyperparathyroidism and parathyroid adenoma, confirmed by biochemical assay, technetium-99 sestamibi scintigraphy, and pathology report, after parathyroid surgery. All patients were examined on conventional 2B ultrasound, 2D shear wave elastography, and strain elastography. We determined using 2D shear wave elastography (SWE) the elasticity index (EI) in parathyroid adenoma, thyroid parenchyma, and surrounding muscle and examined using strain elastography the parathyroid adenoma, and determined the strain ratio with the thyroid tissue and muscle tissue.

RESULTS

All patients had positive sestamibi scintigraphy and underwent surgery, with confirmation of parathyroid adenoma in all cases. The mean parathormone (PTH) value before surgery was 153.29 pg/ml (36.5, 464.8) and serum calcium concentration was 10.5 mg/dl (9, 11.5). We compared using 2D-SWE and strain elastography parathyroid adenoma with thyroid tissue and with surrounding muscle. The mean EI measured by SWE in parathyroid adenoma was 4.74 ± 2.74 kPa and in thyroid parenchyma was 11.718 ± 4.206 kPa (mean difference = 6.978 kPa, p < 0.001), and the mean EI value in muscle tissue was 16.362 ± 3.829 kPa (mean difference = 11.622, p < 0.001). Using ROC analysis, we found that an EI below 7 kPa correctly identifies parathyroid tissue. We evaluated parathyroid adenomas using strain elastography by color mapping and strain ratio as a semiquantitative measurement; however, we could not find any statistical correlation comparing the strain ratio obtained from the parathyroid adenoma with the thyroid tissue (p=0.485).

CONCLUSION

Ultrasound elastography is a helpful tool in identifying parathyroid adenomas. A cutoff value below 7 kPa can be used in 2D-SWE. Color maps in strain elastography without adding strain ratio can be used, parathyroid adenoma being identified as score 1 in the Rago criteria.

Shear Wave Elastography in Diagnosing Secondary Hyperparathyroidism

This study evaluates the diagnostic value of two-dimensional shear wave elastography (2 D-SWE) technique in the evaluation of hyperplastic parathyroid glands in cases with secondary and tertiary hyperparathyroidism. A total of 59 patients (end-stage renal disease, under supplemental dialysis program) with visible parathyroid hyperplastic glands on ultrasound, confirmed by biochemical assay and scintigraphy, were enrolled; they were examined on grayscale ultrasound and 2 D shear wave elastography. We determined the elasticity index (EI) in the parathyroid gland, thyroid parenchyma and surrounding muscles, and the elasticity ratio of hyperplastic parathyroid glands compared to muscle, specifically sternocleidomastoid muscle. Patients presented fibrocystic bone disease with secondary hyperparathyroidism induced by end-stage chronic kidney disease; being on prolonged chronic dialysis therapy, they had positive sestamibi scintigraphy and high values of serum parathormone (1141.04 pg/mL). Nodules placed posterior to the thyroid capsule that were cystic, had a hypoechoic aspect, and were homogenous with an independent afferent artery were found. Mean EI in the parathyroid gland was 7.83 kPa, the median value in thyroid parenchyma was 13.76 kPa, and mean muscle EI value was 15.78 kPa. The observed mean parathyroid/muscle SWE ratio was 0.5356 and the value for parathyroid/normal thyroid parenchyma was 0.5995. Using receiver operating characteristic (ROC) analysis, we found that EI below 9.74 kPa correctly identifies parathyroid tissue, with a sensitivity of 94.8%, specificity of 90.7%, and accuracy of 92.26% when compared to normal thyroid tissue. Compared with the muscle tissue, we identified that EI below 9.98 kPa has a sensitivity, specificity, and accuracy of 93.8%, 90.7%, and 91.75%, respectively. Ultrasound elastography is a helpful tool in identifying parathyroid hyperplasia in patients with chronic kidney disease. A cutoff value of 9.98 kPa can be used in 2 D-SWE for accurate diagnosis of parathyroid disease.

Utility of 2D-ultrasound in pelvic floor muscle contraction and bladder neck mobility assessment in women with urinary incontinence

INTRODUCTION AND HYPOTHESIS

Assessment of pelvic floor muscle (PFM) contraction and bladder neck (BN) mobility in women with stress urinary incontinence (SUI) is essentially clinical. Ultrasound is increasingly used as a method for evaluating BN mobility and PFM contraction, but has not been standardized. The aim of this study was to review ultrasound technics and parameters that might be relevant for PFM contraction and BN mobility assessment in women with urinary incontinence (UI).

METHODS

We reviewed articles indexed in the MEDLINE database between 1988 and 2018 and selected articles which had a cohort of women with UI who had undergone functional 2D-ultrasound evaluation of PFM or BN mobility.

RESULTS

Transperineal ultrasound provides a panoramic view of the pelvic organs without modifying the anatomical relationship between the urethra and surrounding structural landmarks. One of the measurements used to assess urethral mobility is bladder neck descent (BND), which has been shown to be extremely reliable. Measuring the anteroposterior diameter (APD) of the urogenital levator hiatus can also reliably quantify PFM contraction in women. The more recently developed technique of elastography could be an additional useful non-invasive method for measuring periurethral striated muscle stiffness.

CONCLUSIONS

Several ultrasound parameters such as BND, anorectal angle displacement and periurethral stiffness as measured by elastography are relevant for investigating UI in women undertaking pelvic floor muscle training. Our hypothesis is that these ultrasound parameters can be correlated with urinary symptoms and clinical contraction assessment. They need to be validated for clinical use.

Qualitative Classification of Shear Wave Elastography for Differential Diagnosis Between Benign and Metastatic Axillary Lymph Nodes in Breast Cancer

Purpose: To examine diagnostic performance of qualitative shear wave elastography (SWE) for evaluation of status of axillary lymph nodes (ALN) in comparison with conventional ultrasonograghy (US) and quantitative SWE parameters. Methods: A total of 118 patients were enrolled, who were all scheduled for breast cancer surgery and core needle biopsy. Conventional US and SWE were performed before biopsy. Based on qualitative evaluation of each ALN, the SWE images were classified into four color patterns: Color Pattern 1: homogeneous; Color Pattern 2: filling defect within lymph node (LN); Color Pattern 3: homogeneous within LN with a localized colored area at the margin; and Color Pattern 4: filling defect within LN with a localized colored area at the margin. The diagnostic performances of the three methods were compared. Results: There were 60 metastatic nodes and 61 benign nodes in the 121 ALNs. Benign ALNs were presented as Color Pattern 1 while metastatic ALNs usually were presented as Color Pattern 2 to 4 (p < 0.05). The AUC of qualitative SWE classification was 0.983, higher than that of quantitative SWE parameters and conventional US (p<0.05). The highest diagnostic performance, with AUC of 0.998, could be achieved if both conventional US and qualitative SWE were applied. Conclusion: The qualitative SWE classification of ALNs proposed in our study exhibited better diagnostic performance than quantitative SWE parameters and conventional US, especially for differentiating metastatic ALNs from benign reactive ALNs. More accurate diagnosis could be reached with this new method and unnecessary biopsy might be avoided in the meantime.

Utilizing size-based thresholds of stiffness gradient to reclassify BI-RADS category 3-4b lesions increases diagnostic performance

AIM

To investigate the role of utilizing size-based thresholds of stiffness gradient in diagnosing solid breast lesions and optimizing original Breast Imaging-Reporting And Data System (BI-RADS) classifications.

MATERIALS AND METHODS

Two-hundred and twenty-seven consecutive women underwent shear-wave elastography (SWE) before ultrasound-guided biopsy, and 234 solid breast lesions categorized as BI-RADS 3-5 were analysed. Receiver operating characteristic curve analysis was performed based on histopathology. Diagnostic performance among SWE, BI-RADS, and their combination were compared.

RESULTS

The stiffness gradient correlated with the standard deviation of elasticity (SD, r=0.90), and with Tozaki's pattern classification (r=0.64). The area under the receiver operating characteristic curves (AUC) for stiffness gradient (0.939) outperformed SD (0.897) or colour pattern (0.852). Due to significant association with lesion size (r=0.394, p<0.001), stiffness gradient's size-based thresholds (lesions >15 mm: 82.5 kPa; lesions ≤15 mm: 51.1 kPa) were established to reclassify BI-RADS 3-4b lesions. Upgrading category 3 lesions (over the corresponding cut-off value, 3 to 4a) and downgrading categories 4a-4b lesions (less than or equal to the corresponding cut-off value, 4b to 4a, 4a to 3), yielded significant improvement in specificity (90.28% versus 77.78%, p<0.001) and AUC (0.948 versus 0.926, p=0.035) than BI-RADS alone. No significant loss emerged in the sensitivity (88.89% versus 91.11%, p=0.500).

CONCLUSION

Stiffness gradient exhibited better discriminatory ability than SD or four-colour pattern classification in determining solid breast lesions and applying its size-specific thresholds to categorize BI-RADS 3-4b lesions could improve diagnostic performance.

Evaluating the role of strain ratio elastography in determining malignancy potential and calculating objective BIRADS US scores using ultrasonography and elastography features

Purpose

The aims of this study were, firstly, to evaluate solid breast masses based on their malignancy potential and to determine whether the strain elastography ratio (SER) can contribute to classical grey-scale ultrasonography findings, and secondly, to define objective BIRADS US scores using ultrasound (US) and SER findings.

Material and methods

A total of 280 patients and 297 solid breast masses were evaluated using sonographic and elastographic data. The SER was measured for each lesion.

Results

The positive predictive values (PPV) for each criterion was calculated to be between 35% and 83.3%. The lowest PPV was obtained from hypoechogenicity (35%) and the highest PPV was obtained for anti-parallel features (83.3%). The difference between the mean SER of benign and malignant lesions was statistically significant. After ROC analysis, the SER cut-off value was calculated to be 3.1 for determining if the mass was benign or malignant. Mass scores were calculated for each solid breast mass based on positive predictive values, and BIRADS US score was defined as the sum of mass scores.

Conclusions

SER findings can be used as malignancy criteria in evaluating solid breast masses. BIRADS US score can be objectively determined based on US and elastography features instead of doing subjective scoring. As an additional result, all solid breast masses have the possibility to be malignant, even though US and elastography findings indicate the opposite.

Confirmed value of shear wave elastography for ultrasound characterization of breast masses using a conservative approach in Chinese women: a large-size prospective multicenter trial

Purpose

This study aimed to investigate the value of shear wave elastography (SWE) for characterization of breast masses in a Chinese population.

Patients and methods

Two thousand two hundred seventy-three women consented to be prospectively enrolled for the characterization of breast masses with ultrasound and SWE. Breast masses were known from symptoms, palpability, and/or previous imaging screening with mammography and/or ultrasound. Correlation of SWE qualitative and quantitative features with malignancy risk and impact on diagnostic performance of combining SWE features were assessed, and the Breast Imaging Reporting and Data System (BI-RADS) scoring was calculated using histopathology as reference.

Results

Data of 2,262 masses (median size: 13 mm; range: 1.3-50) from 2,262 patients (median age: 43 years; range: 18-91) were investigated, of which 752 (33.3%) were malignant. Sensitivity and specificity of BI-RADS diagnosis were 97.5% (733/752) and 54.8% (827/1,510), respectively. By logistic regression, the combination of maximum elasticity (E _max) measurements with BI-RADS assessments increased the area under the receiver operating characteristic curve from 0.908 (95% CI: 0.896-0.920) to 0.954 (95% CI: 0.944-0.962). Using E _max of 30 kPa or lower to selectively downgrade BI-RADS 4a masses to follow-up, and E _max of 160 kPa or higher to selectively upgrade BI-RADS 3 lesions to biopsy, specificity significantly increased from 54.8% (827/1,510) to 66.1% (998/1,510) (P<0.001) while sensitivity decreased nonsignificantly from 97.5% (733/752) to 96.9% (729/752) (P=0.2891). Positive predictive value for biopsy recommendation increased from 51.7% (733/1,417) to 58.7% (729/1,241) (P<0.001).

Conclusion

Adding SWE maximum stiffness to BI-RADS 3 and BI-RADS 4a breast masses in a Chinese population increased significantly the specificity of breast ultrasonography, without significant change in sensitivity.

Breast lesions diagnosed by ultrasound-guided core needle biopsy: Can shearwave elastography predict histologic upgrade after surgery or vaccuum assisted excision?

PURPOSE

To compare breast stiffness based on shear-wave elastography (SWE) quantitative parameters with histopathologic results diagnosed by ultrasound (US)-guided core needle biopsy (CNB) to determine their association with upgrade rates after surgical excision or follow-up US as well as clinico-radiologic differences between upgrade and non-upgrade groups.

MATERIALS AND METHODS

This retrospective study enrolled 225 breast lesions from 225 patients, including 159 benign lesions, 38 high risk lesions and 28 ductal carcinoma in situ (DCIS) diagnosed by US-guided CNB. Quantitative SWE parameters of breast lesions were measured before CNB and compared according to histopathologic results (benign, high risk and DCIS) and lesion size (<20 mm and >20 mm). Clinico-radiologic and pathologic factors were compared between upgrade and non-upgrade groups after surgical excision or follow-up US.

RESULTS

After surgical excision or follow-up US after more than one year, 29 lesions were upgraded for an overall upgrade rate of 12.9% (29/225). There were significant differences between upgrade and non-upgrade groups in age, mammographic category, US category, and sonographic features, including shape, margin, orientation, imaging-histologic correlation and E ratio. Patients with lesion upgrade were much older and had lesions characterized by significantly higher mammographic and US category (>4b), irregular shape, nonparallel orientation, microlobulated or angular margin, calcification in a mass, larger size on US (>20 mm) and greater imaging-histologic discordance. Multivariate analysis showed only mean and minimum elasticity values displayed a borderline association with histologic underestimation.

CONCLUSION

Upgrade of breast lesions diagnosed by US-guided CNB can be predicted using E_mean and E_min among quantitative SWE parameters.

Breast lesion classification based on supersonic shear-wave elastography and automated lesion segmentation from B-mode ultrasound images

Supersonic shear-wave elastography (SWE) has emerged as a useful imaging modality for breast lesion assessment. Regions of interest (ROIs) were required to be specified for extracting features that characterize malignancy of lesions. Although analyses have been performed in small rectangular ROIs identified manually by expert observers, the results were subject to observer variability and the analysis of small ROIs would potentially miss out important features available in other parts of the lesion. Recent investigations extracted features from the entire lesion segmented by B-mode ultrasound images either manually or semi-automatically, but lesion delineation using existing techniques is time-consuming and prone to variability as intensive user interactions are required. In addition, rich diagnostic features were available along the rim surrounding the lesion. The width of the rim analyzed was subjectively and empirically determined by expert observers in previous studies after intensive visual study on the images, which is time-consuming and susceptible to observer variability. This paper describes an analysis pipeline to segment and classify lesions efficiently. The lesion boundary was first initialized and then deformed based on energy fields generated by the dyadic wavelet transform. Features of the SWE images were extracted from inside and outside of a lesion for different widths of the surrounding rim. Then, feature selection was performed followed by the Support Vector Machine (SVM) classification. This strategy obviates the empirical and time-consuming selection of the surrounding rim width before the analysis. The pipeline was evaluated on 137 lesions. Feature selection was performed 20 times using different sets of 14 lesions (7 malignant, 7 benign). Leave-one-out SVM classification was performed in each of the 20 experiments with a mean sensitivity, specificity and accuracy of 95.1%, 94.6% and 94.8% respectively. The pipeline took an average of 20 s to process a lesion. The fact that this efficient pipeline generated classification accuracy superior to that of existing algorithms suggests that improved efficiency did not compromise classification accuracy. The ability to streamline the quantitative assessment of SWE images will potentially accelerate the adoption of the combined use of ultrasound and elastography in clinical practice.

Value of shear wave elastography in discriminating malignant and benign breast lesions: A meta-analysis

The analysis was aimed to evaluate the diagnostic accuracy of shear wave elastography (SWE) for malignant breast lesions through a meta-analysis.Related articles were searched from Pubmed, Embase, and Cochrane library. Overall sensitivity and specificity were analyzed with DerSimonian and Laird random effects model. Area under curve with corresponding 95% confidence interval (were calculated to evaluate the diagnostic accuracy of SWE. Sensitivity and publication bias were assessed as well.A total of 25 articles including 4128 patients and 4546 breast lesions were included in the pooled analysis. In the subgroup analysis, diagnostic sensitivity and specificity of SWE in Asian population were 0.84 (0.79-0.88) and 0.87 (0.84-0.90), respectively, whereas they were 0.92 (0.86-0.96) and 0.89 (0.84-0.92) in Caucasian population. The diagnostic accuracy of SWE was a little higher for Caucasians than for Asians (0.95 vs. 0.92). The diagnostic sensitivity and specificity of virtual touch tissue quantification were 0.85 (0.77-0.91) and 0.93 (0.88-0.96), respectively. It showed a little higher value in specificity and summary ROC curve than SWE (0.93 vs. 0.87; 0.95 vs. 0.93). In addition, maximum stiffness exhibited higher detection sensitivity than that of mean stiffness (0.91 vs. 0.85).SWE serves as an accurate diagnostic technology for discriminating between malignant and benign breast lesions.

Benign and malignant breast lesions identification through the values derived from shear wave elastography: evidence for the meta-analysis

Objective

The analysis was aimed to evaluate the diagnostic accuracy of shear wave elastography (SWE) for malignant breast lesions through a meta-analysis.

Materials and Methods

Related articles were searched in databases of Pubmed, Embase and Cochrane library. Overall sensitivity and specificity were analyzed with DerSimonian and Laird random effects model. Area under curve (AUC) with corresponding 95% confidence interval were also analyzed to evaluate the diagnostic accuracy of SWE. P value < 0.05 predicted the significant heterogeneity between study. Sensitivity and publication bias were assessed as well.

Results

According to the inclusion criteria, 25 articles were selected. In the subgroup analysis, diagnostic sensitivity and specificity of SWE in Asian population were 0.84 (0.79-0.88) and 0.87 (0.84-0.90), respectively, while they were 0.92 (0.86-0.96) and 0.89 (0.84-0.92) in Caucasian population. The diagnostic accuracy of SWE was a little higher for Caucasians than for Asians (0.95 vs. 0.92). The diagnostic sensitivity and specificity of virtual touch tissue quantification (VTTQ) were 0.85 (0.77-0.91) and 0.93 (0.88-0.96), respectively. It showed a little higher value in specificity and summary receiver operating curve (sROC) than that of SWE (0.93 vs. 0.87; 0.95 vs. 0.93). In addition, maximum stiffness exhibited higher detection sensitivity than that of mean stiffness (0.91 vs. 0.85).

Conclusions

SWE serves as an accurate diagnostic technology for discriminating malignant and benign breast lesions.

Shear-wave elastography in breast ultrasonography: the state of the art

Shear-wave elastography (SWE) is a recently developed ultrasound technique that can visualize and measure tissue elasticity. In breast ultrasonography, SWE has been shown to be useful for differentiating benign breast lesions from malignant breast lesions, and it has been suggested that SWE enhances the diagnostic performance of ultrasonography, potentially improving the specificity of conventional ultrasonography using the Breast Imaging Reporting and Data System criteria. More recently, not only has SWE been proven useful for the diagnosis of breast cancer, but has also been shown to provide valuable information that can be used as a preoperative predictor of the prognosis or response to chemotherapy.

Usefulness of transabdominal real-time sonoelastography in the evaluation of ovarian lesions: preliminary results

OBJECTIVE

We aim to evaluate and describe the tissue elasticity characteristics of various ovarian lesions with sonoelastography.

METHODS

35 patients (age range 16-85 years; mean age 40.8 years) underwent sonoelastography and later MRI. Histopathological confirmation of all lesions was carried out, except eight of endometriomas and six of septated cysts which were confirmed on MRI and follow-up ultrasonography. Strain ratios and elastogram patterns were recorded. Lesions were classified into three groups (Group 1: cystic lesions, Group 2: benign tumours and Group 3: malignant lesions) and findings were compared between groups for both observers. Interobserver agreement was analyzed. Optimal cut-off values for strain ratios were achieved with receiver operating characteristic curve analysis.

RESULTS

Ovarian endometriomas and complex cystic lesions were observed hard on elastograms with high strain ratios, and malignant lesions were observed mostly soft with very small strain ratios. Benign tumours had average tissue stiffness, observed harder than the malignant lesions, and strain ratios ranged from 4 to 14. The differences in patterns and strain ratios between groups were statistically significant (p < 0.05 for both observers).

CONCLUSION

Our study revealed that malignant ovarian lesions have softer tissue property than benign lesions and cystic lesions in terms of elastogram patterns and strain ratios.

ADVANCES IN KNOWLEDGE

Most ovarian lesions contain solid and cystic parts which make the malignant and benign lesions look similar on imaging modalities. Using real-time sonoelastography as an adjunct to other imaging modalities may improve the differentiation of malignant ovarian lesions from benign lesions.

Breast Lesions: Quantitative Diagnosis Using Ultrasound Shear Wave Elastography-A Systematic Review and Meta--Analysis

The aim of this meta-analysis was to estimate the diagnostic performance of shear wave elastography (SWE) in differentiating malignant from benign breast lesions. A literature search of PubMed, Web of Science and Scopus up to November 2014 was conducted. A summary receiver operating characteristic curve was constructed, and pooled weighted estimates of sensitivity and specificity were calculated using a bivariate mixed-effects regression model. Thirty-three studies, which included a total of 5838 lesions (2093 malignant, 3745 benign) from 5397 patients, were finally analyzed. Summary sensitivity and specificity were 0.886 (95% confidence interval [CI], 0.858-0.909) and 0.866 (95% CI, 0.833-0.894), respectively. The pooled diagnostic odds ratio was 50.410 (95% CI, 34.972-72.664). And the area under the receiver operating characteristic curve of SWE was 0.94 (95% CI, 0.91-0.96). No publication bias existed among these studies (p = 0.245). In the subgroup analysis, sensitivity and specificity were 0.862 (95% CI, 0.811-0.901) and 0.875 (95% CI, 0.793-0.928) among 1552 lesions from 1429 patients in the 12 studies using acoustic radiation force impulse imaging and 0.897 (95% CI, 0.863-0.923) and 0.863 (95% CI, 0.831-0.889) among another 4436 lesions from 4097 patients in the 21 studies using supersonic shear imaging. When analysis confined to 9 studies evaluated the diagnostic performance of combination SWE and conventional ultrasound, the area under the curve was 0.96 (95% CI, 0.94-0.97), yielding a sensitivity of 0.971 (95% CI, 0.941-0.986) and specificity of 0.801 (95% CI, 0.733-0.856). SWE seems to be a good quantitative method for differentiating breast lesions, with promise for integration into routine imaging protocols.

Lesion stiffness measured by shear-wave elastography: Preoperative predictor of the histologic underestimation of US-guided core needle breast biopsy

OBJECTIVES

To determine whether lesion stiffness measured by shear-wave elastography (SWE) can be used to predict the histologic underestimation of ultrasound (US)-guided 14-gauge core needle biopsy (CNB) for breast masses.

METHODS

This retrospective study enrolled 99 breast masses from 93 patients, including 40 high-risk lesions and 59 ductal carcinoma in situ (DCIS), which were diagnosed by US-guided 14-gauge CNB. SWE was performed for all breast masses to measure quantitative elasticity values before US-guided CNB. To identify the preoperative factors associated with histologic underestimation, patients' age, symptoms, lesion size, B-mode US findings, and quantitative SWE parameters were compared according to the histologic upgrade after surgery using the chi-square test, Fisher's exact test, or independent t-test. The independent factors for predicting histologic upgrade were evaluated using multivariate logistic regression analysis.

RESULTS

The underestimation rate was 28.3% (28/99) in total, 25.0% (10/40) in high-risk lesions, and 30.5% (18/59) in DCIS. All elasticity values of the upgrade group were significantly higher than those of the non-upgrade group (P<0.001). On multivariate analysis, the mean (Odds ratio [OR]=1.021, P=0.001), maximum (OR=1.015, P=0.008), and minimum (OR=1.028, P=0.001) elasticity values were independently associated with histologic underestimation. The patients' age, lesion size, and final assessment category on US of the upgrade group were higher than those of the non-upgrade group (P=0.046 for age; P=0.021 for lesion size; P=0.030 for US category), but these were not independent predictors of histologic underestimation on multivariate analysis.

CONCLUSION

Breast lesion stiffness quantitatively measured by SWE could be helpful to predict the underestimation of malignancy in US-guided 14-gauge CNB.

Quantitative Lesion-to-Fat Elasticity Ratio Measured by Shear-Wave Elastography for Breast Mass: Which Area Should Be Selected as the Fat Reference?

OBJECTIVES

To investigate whether the diagnostic performance of lesion-to-fat elasticity ratio (Eratio) was affected by the location of the reference fat.

METHODS

For 257 breast masses in 250 women who underwent shear-wave elastography before biopsy or surgery, multiple Eratios were measured with a fixed region-of-interest (ROI) in the mass along with multiple ROIs over the surrounding fat in different locations. Logistic regression analysis was used to determine that Eratio was independently associated with malignancy adjusted for the location of fat ROI (depth, laterality, and distance from lesion or skin). Mean (Emean) and maximum (Emax) elasticity values of fat were divided into four groups according to their interquartile ranges. Diagnostic performance of each group was evaluated using the area under the ROC curve (AUC). False diagnoses of Eratio were reviewed for ROIs on areas showing artifactual high or low stiffness and analyzed by logistic regression analysis to determine variables (associated palpable abnormality, lesion size, the vertical distance from fat ROI to skin, and elasticity values of lesion or fat) independently associated with false results.

RESULTS

Eratio was independently associated with malignancy adjusted for the location of fat ROI (P<0.0001). Among four groups of fat elasticity values, the AUC showed no significant difference (<25th percentile, 25th percentile~median, median~75th percentile, and ≥75th percentile; 0.973, 0.982, 0.967, and 0.954 for Emean; 0.977, 0.967, 0.966, and 0.957 for Emax). Fat elasticity values were independently associated with false results of Eratio with the cut-off of 3.18 from ROC curve (P<0.0001). ROIs were set on fat showing artifactual high stiffness in 90% of 10 false negatives and on lesion showing vertical striped artifact or fat showing artifactual low stiffness in 77.5% of 71 false positives.

CONCLUSION

Eratio shows good diagnostic performance regardless of the location of reference fat, except when it is placed in areas of artifacts.

Quantification of elastic heterogeneity using contourlet-based texture analysis in shear-wave elastography for breast tumor classification

Ultrasound shear-wave elastography (SWE) has become a valuable tool for diagnosis of breast tumors. The purpose of this study was to quantify the elastic heterogeneity of breast tumors in SWE by using contourlet-based texture features and evaluating their diagnostic performance for classification of benign and malignant breast tumors, with pathologic results as the gold standard. A total of 161 breast tumors in 125 women who underwent B-mode and SWE ultrasonography before biopsy were included. Five quantitative texture features in SWE images were extracted from the directional subbands after the contourlet transform, including the mean (Tmean), maximum (Tmax), median (Tmed), third quartile (Tqt), and standard deviation (Tsd) of the subbands. Diagnostic performance of the texture features and the classic features was compared using the area under the receiver operating characteristic curve (AUC) and the leave-one-out cross validation with Fisher classifier. The feature Tmean achieved the highest AUC (0.968) among all features and it yielded a sensitivity of 89.1%, a specificity of 94.3% and an accuracy of 92.5% for differentiation between benign and malignant tumors via the leave-one-out cross validation. Compared with the best classic feature, i.e., the maximum elasticity, Tmean improved the AUC, sensitivity, specificity and accuracy by 3.5%, 12.7%, 2.8% and 6.2%, respectively. The Tmed, Tqt and Tsd were also superior to the classic features in terms of the AUC and accuracy. The results demonstrated that the contourlet-based texture features captured the tumor's elastic heterogeneity and improved diagnostic performance contrasted with the classic features.

Diagnostic performances of shear-wave elastography for identification of malignant breast lesions: a meta-analysis

PURPOSE

To examine the performance of shear-wave elastography (SWE) for the differentiation of benign and malignant breast lesions using a meta-analysis.

MATERIALS AND METHODS

PubMed, Embase and the Cochrane library were searched for studies published up to January 2014. The references of retrieved relevant articles were reviewed to identify potential publications. Random-effect meta-analysis was conducted to assess the overall sensitivity and specificity of SWE in the differentiation of breast lesions.

RESULTS

A total of 11 articles, including 2424 patients, were included in the present meta-analysis. The summarized sensitivity and specificity of the shear wave elastography performance based on maximum elasticity were 0.93 (95 % CI 0.91-0.95) and 0.81 (95 % CI 0.78-0.83), respectively. For the mean elasticity, the summarized sensitivity and specificity were 0.94 (95 % CI 0.92-0.96) and 0.71 (95 % CI 0.69-0.74), respectively. The summarized sensitivity and specificity were 0.77 (95 % CI 0.70-0.83) and 0.88 (95 % CI 0.84-0.91) for the SD of elasticity.

CONCLUSION

SWE has a high sensitivity and specificity in the differentiation of benign and malignant breast lesions. More large and prospective studies are warranted to further examine the performance of SWE.

Practice guideline for the performance of breast ultrasound elastography

Ultrasound (US) elastography is a valuable imaging technique for tissue characterization. Two main types of elastography, strain and shear-wave, are commonly used to image breast tissue. The use of elastography is expected to increase, particularly with the increased use of US for breast screening. Recently, the US elastographic features of breast masses have been incorporated into the 2nd edition of the Breast Imaging Reporting and Data System (BI-RADS) US lexicon as associated findings. This review suggests practical guidelines for breast US elastography in consensus with the Korean Breast Elastography Study Group, which was formed in August 2013 to perform a multicenter prospective study on the use of elastography for US breast screening. This article is focused on the role of elastography in combination with B-mode US for the evaluation of breast masses. Practical tips for adequate data acquisition and the interpretation of elastography results are also presented.