Breast mass characterization using shear wave elastography and ultrasound

Predictive value of contrast-enhanced ultrasonography and ultrasound elastography for management of BI-RADS category 4 nonpalpable breast masses

PURPOSE

The objective of this study was to investigate the independent risk factors and associated predictive values of contrast-enhanced ultrasound (CEUS), shear wave elastography (SWE), and strain elastography (SE) for high-risk lesions (HRL) and malignant tumors (MT) among nonpalpable breast masses classified as BI-RADS category 4 on conventional ultrasound.

METHODS

This prospective study involved consecutively admitted patients with breast tumors from January 2018, aiming to explore the management of BI-RADS category 4 breast tumors using CEUS and elastography. We conducted a retrospective review of patient data, focusing on those with a history of a nonpalpable mass as the primary complaint. Pathologic findings after surgical resection served as the gold standard. The CEUS arterial-phase indices were analyzed using contrast agent arrival-time parametric imaging processing mode, while quantitative and qualitative indices were examined on ES images. Independent risk factors were identified through binary logistic regression multifactorial analysis. The predictive efficacy of different modalities was compared using a receiver operating characteristics curve. Subsequently, a nomogram for predicting the risk of HRL/MT was established based on a multifactorial logistic regression model.

RESULTS

A total of 146 breast masses from 146 patients were included, comprising 80 benign tumors, 12 HRLs, and 54 MTs based on the final pathology. There was no significant difference in pathologic size between the benign and HRL/MT groups [8.00(6.25,10.00) vs. 9.00(6.00,10.00), P = 0.506]. The diagnostic efficacy of US plus CEUS exceeded that of US plus SWE/SE for BI-RADS 4 nonpalpable masses, with an AUC of 0.954 compared to 0.798/0.741 (P ＜ 0.001). Further stratified analysis revealed a more pronounced improvement for reclassification of BI-RADS 4a masses (AUC: 0.943 vs. 0.762/0.675, P ＜ 0.001) than BI-RADS 4b (AUC:0.950 vs. 0.885/0.796, P＞0.05) with the assistance of CEUS than SWE/SE. Employing downgrade CEUS strategies resulted in negative predictive values ranging from 95.2 % to 100.0 % for BI-RADS 4a and 4b masses. Conversely, using upgrade nomogram strategies, which included the independent predictive risk factors of irregular enhanced shape, poor defined enhanced margin, earlier enhanced time, increased surrounding vessels, and presence of contrast agent retention, the diagnostic performance achieved an AUC of 0.947 with good calibration.

CONCLUSION

After investigating the potential of CEUS and ES in improving risk assessment and diagnostic accuracy for nonpalpable BI-RADS category 4 breast masses, it is evident that CEUS has a more significant impact on enhancing classification compared to ES, particularly for BI-RADS 4a subgroup masses. This finding suggests that CEUS may offer greater benefits in improving risk assessment and diagnostic accuracy for this specific subgroup of breast masses.

Automatic Breast Volume Scanner and B-Ultrasound-Based Radiomics Nomogram for Clinician Management of BI-RADS 4A Lesions

RATIONALE AND OBJECTIVES

To develop and validate a nomogram for predicting the risk of malignancy of breast imaging reporting and data system (BI-RADS) 4A lesions to reduce unnecessary invasive examinations.

MATERIALS AND METHODS

From January 2017 to July 2021, 190 cases of 4A lesions included in this study were divided into training and validation sets in a ratio of 8:2. Radiomics features were extracted from sonograms by Automatic Breast Volume Scanner (ABVS) and B-ultrasound. We constructed the radiomics model and calculated the rad-scores. Univariate and multivariate logistic regressions were used to assess demographics and lesion elastography values (virtual touch tissue image, shear wave velocity) and to develop clinical model. A clinical radiomics model was developed using rad-score and independent clinical factors, and a nomogram was plotted. Nomogram performance was evaluated using discrimination, calibration, and clinical utility.

RESULTS

The nomogram included rad-score, age, and elastography, and showed good calibration. In the training set, the area under the receiver operating characteristic curve (AUC) of the clinical radiomics model (0.900, 95% confidence interval (CI): 0.843-0.958) was superior to that of the radiomics model (0.860, 95% CI: 0.799-0.921) and clinical model (0.816, 95% CI: 0.735-0.958) (p = 0.024 and 0.008, respectively). The decision curve analysis showed that the clinical radiomics model had the highest net benefit in most threshold probability ranges.

CONCLUSION

ABVS and B-ultrasound-based radiomics nomograms have satisfactory performance in differentiating benign and malignant 4A lesions. This can help clinicians make an accurate diagnosis of 4A lesions and reduce unnecessary biopsy.

Correlation of Shear-Wave Elastography and Apparent Diffusion Coefficient Values in Breast Cancer and Their Relationship with the Prognostic Factors

Background: Diffusion-weighted imaging and elastography are widely accepted methods in the evaluation of breast masses, however, there is very limited data comparing the two methods. The apparent diffusion coefficient is a measure of the diffusion of water molecules obtained by diffusion-weighted imaging as a part of breast MRI. Breast elastography is an adjunct to conventional ultrasonography, which provides a noninvasive evaluation of the stiffness of the lesion. Theoretically, increased tissue density and stiffness are related to each other. The purpose of this study is to compare MRI ADC values of the breast masses with quantitative elastography based on ultrasound shear wave measurements and to investigate their possible relation with the prognostic factors and molecular subtypes. Methods: We retrospectively evaluated histopathologically proven 147 breast lesions. The molecular classification of malignant lesions was made according to the prognostic factors. Shear wave elastography was measured in kiloPascal (kPa) units which is a quantitative measure of tissue stiffness. DWI was obtained using a 1.5-T MRI system. Results: ADC values were strongly inversely correlated with elasticity (r = −0.662, p < 0.01) according to Pearson Correlation. In our study, the cut-off value of ADC was 1.00 × 10−3 cm2/s to achieve a sensitivity of 84.6% and specificity of 75.4%, and the cut-off value of elasticity was 105.5 kPa to achieve the sensitivity of 96.3% and specificity 76.9% to discriminate between the malignant and benign breast lesions. The status of prognostic factors was not correlated with the ADC values and elasticity. Conclusions: Elasticity and ADC values are correlated. Both cannot predict the status of prognostic factors and differentiate between molecular subtypes.

Multi-parameter ultrasonography-based predictive model for breast cancer diagnosis

OBJECTIVES

To develop, validate, and evaluate a predictive model for breast cancer diagnosis using conventional ultrasonography (US), shear wave elastography (SWE), and contrast-enhanced US (CEUS).

MATERIALS AND METHODS

This retrospective study included 674 patients with 674 breast lesions. The data, a main and an independent datasets, were divided into three cohorts. Cohort 1 (80% of the main dataset; n = 448) was analyzed by logistic regression analysis to identify risk factors and establish the predictive model. The area under the receiver operating characteristic curve (AUC) was analyzed in Cohort 2 (20% of the main dataset; n = 119) to validate and in Cohort 3 (the independent dataset; n = 107) to evaluate the predictive model.

RESULTS

Multivariable regression analysis revealed nine independent breast cancer risk factors, including age > 40 years; ill-defined margin, heterogeneity, rich blood flow, and abnormal axillary lymph nodes on US; enhanced area enlargement, contrast agent retention, and irregular shape on CEUS; mean SWE higher than the cutoff value (P < 0.05 for all). The diagnostic performance of the model was good, with AUC values of 0.847, 0.857, and 0.774 for Cohorts 1, 2, and 3, respectively. The model increased the diagnostic specificity (from 31% to 81.3% and 7.3% to 73.1% in cohorts 2 and 3, respectively) without a significant loss in sensitivity (from 100.0% to 90.1% and 100.0% to 81.8% in cohorts 2 and 3, respectively).

CONCLUSION

The multi-parameter US-based model showed good performance in breast cancer diagnosis, improving specificity without a significant loss in sensitivity. Using the model could reduce unnecessary biopsies and guide clinical diagnosis and treatment.

Differential diagnosis of B-mode ultrasound Breast Imaging Reporting and Data System category 3-4a lesions in conjunction with shear-wave elastography using conservative and aggressive approaches

BACKGROUND

The high false-positive rates of US Breast Imaging Reporting and Data System (BI-RADS) category 3-4a breast lesions leads to excessive biopsies of many benign lesions, and our aim was to investigate the diagnostic performance achieved by adding a maximum elasticity (Emax) of shear-wave elastography (SWE) to ultrasound (US) to evaluate US BI-RADS category 3-4a breast lesions using conservative and aggressive approaches. We explored the capacity of using this method to avoid unnecessary biopsies without increasing the probability of missing breast cancers.

METHODS

A total of 123 breast lesions of 120 patients classified as BI-RADS category 3 or 4a were enrolled from January 2019 to December 2019. The US features were evaluated according to the US BI-RADS lexicon. The maximum diameter measured on the US was defined as the size of the lesion. The Emax was assessed by SWE, and the average Emax of breast lesions on two images were calculated and recorded as the final maximum Young's modulus. The diagnostic performance of the combined B-mode US and SWE approach for BI-RADS category 3-4a breast lesions was tested using a conservative approach and an aggressive approach. In the conservative approach, the lesions were downgraded with Emax of 30 kPa or less and upgraded with Emax of 160 kPa or more. In the aggressive approach, the lesions were downgraded with Emax of 80 kPa or less and upgraded with Emax of 160 kPa or more. Pathologic results were defined as the reference standard.

RESULTS

Among all 123 breast lesions, there were 60 lesions classified as BI-RADS category 3 and 63 lesions classified as BI-RADS category 4a. Compared to the B-mode US, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), accuracy, and area under the receiver operating characteristic (ROC) curve (AUC) of the combined B-mode US and SWE with a conservative approach changed from 88.9% to 94.4%, 55.2% to 60.0%, 25.4% to 28.8%, 96.7% to 98.4%, 60.2% to 65.0%, and 0.721 to 0.772, respectively. The specificity, PPV, and accuracy of combined B-mode US and SWE with an aggressive approach increased from 55.2% to 72.4%, 25.4% to 29.3%, and 60.2% to 71.5%, respectively, but this was accompanied with decreases in the sensitivity from 88.9% to 66.7%, the NPV from 96.7% to 92.7%, and the AUC from 0.721 to 0.695.

CONCLUSIONS

The addition of SWE improves the diagnostic performance of breast US. Adding the diagnostic criteria of SWE to the BI-RADS assessment of B-mode US, downgrading the lesions with Emax 30 kPa or less, and upgrading the lesions with Emax 160 kPa or more helped discriminate low suspicion lesions from benign lesions in order to decrease false-positive findings and avoid missing cancer diagnosis.

The Value of High-Resolution Ultrasound Combined with Shear-Wave Elastography under Artificial Intelligence Algorithm in Quantitative Evaluation of Skin Thickness in Localized Scleroderma

The aim of this study was to explore the value of high-resolution ultrasound combined with shear-wave elastography (SWE) in measuring skin thickness in patients with localized scleroderma (LS). Fifty patients with LS diagnosed by pathology in the hospital were selected as the research object, with a total of 96 lesions. Healthy people (50 cases) in the same period were selected as the control group. The skin thickness of the abdomen, chest, and left finger of the two groups was compared. The traditional nonlocal means (NLM) algorithm was improved by changing the Euclidean distance and introducing a cosine function, which was applied to the ultrasonic imaging intelligent diagnosis of patients with localized scleroderma. SWE imaging was evaluated, and the results demonstrated that LS lesion edema stage accounted for 7.29%, hardening stage occupied 43.75%, and the proportion of atrophy stage reached 48.96%. When the size of shell was 1 mm, maximum elastic modulus (Emax) was 0.984, mean of elastic modulus (Emean) was 0.926, and electro-static discharge (Esd) was 0.965. When the size of shell was 2 mm, the elastic moduli around lesions were as follows: Emax was 0.998, Emean was 0.968, and Esd was 0.997. By comparing the skin thickness of the abdomen, chest, and left finger, it was found that there was a significant difference between the LS group and the control group ( $P<0.05$ ). When the shell was 2 mm, the effect of sensitivity specificity on SWE imaging was better than that when the shell was 1 mm. In summary, the improved NLM algorithm showed excellent denoising effects on the ultrasonic images of LS patients. Besides, it could assist clinicians in ultrasonic imaging diagnosis for LS patients and effectively improve the diagnostic accuracy of diseases.

The significance of dual-mode elastography in the diagnosis of breast lesions by physicians with different levels of experience

BACKGROUND

This study aimed to assess the diagnostic value of dual-mode elastography for benign and malignant breast lesions and determine whether this technique can improve the diagnostic ability of physicians with different levels of experience.

METHODS

One hundred and eighty-three breast lesions were analyzed retrospectively, and the following values were calculated for the lesions with various shells: shear modulus (G), Young's modulus (E), shear wave velocity (Cs), and strain ratio (SR). A random forest algorithm was used to select the optimal modes for elastography. A receiver operating characteristic curve was used to assess the diagnostic efficacy for benign and malignant breast lesions. Sensitivity and specificity values were calculated to evaluate any improvements in the diagnostic efficacy of physicians with different levels of experience (junior, intermediate-level, and senior) in the evaluation of malignant breast lesions using dual-mode elastography.

RESULTS

The best-performing mode of shear wave elastography (SWE) in the diagnosis of breast lesions was the A'min 1.0 (Cs) mode (minimum shear wave velocity of the area of interest and 1.0 mm around the area of interest), and the best-performing mode of strain elastography (SE) was the B/A' 0.5 (ratio of fat to the elasticity of the area of interest and 0.5 mm around the area of interest). When the two methods were used in series, results showed high specificity (98%), positive likelihood ratio (PLR) (21.2), and positive predictive value (PPV) (95%). Series means that if SE and SWE were malignant, the result in series was malignant, and that if either SE or SWE was benign, the result in series was benign. When the methods were used in parallel, the results showed high sensitivity (91%), negative likelihood ratio (NLR) (0.15), and negative predictive value (NPV) (89%). Parallel means that if SE and SWE were benign, the result in parallel was benign, and that if either SE or SWE was malignant, the result in parallel was malignant. When conventional ultrasound was combined with dual-mode elastography, the intermediate-level and junior physicians' diagnoses of breast lesions showed a higher sensitivity, specificity, and area under the curve than conventional ultrasound diagnosis alone.

CONCLUSIONS

Dual-mode elastography is effective in the diagnosis of breast lesions. The sensitivity and specificity values in this study show that diagnoses made by junior and intermediate-level physicians improve when dual-mode elastography is used, although diagnoses made by senior physicians do not improve significantly.

TGF-β1 and its signal molecules: are they correlated with the elasticity characteristics of breast lesions?

Background

Shear wave elastography can evaluate tissue stiffness. Previous studies showed that the elasticity characteristics of breast lesions were related to the components of extracellular matrix which was regulated by transforming growth factor beta 1(TGF-β1) directly or indirectly. However, the correlation of the expression level of TGF-β1, its signal molecules and elasticity characteristics of breast lesions have rarely been reported. The purpose of this study was to investigate the correlation between the expression level of TGF-β1, its signal molecules, and the elasticity characteristics of breast lesions.

Methods

135 breast lesions in 130 patients were included. Elasticity parameters, including elasticity modulus, the elasticity ratio, the “stiff rim sign”, were recorded before biopsy and surgical excision. The expression levels of TGF-β1 and its signal molecules, including Smad2/3, Erk1/2, p38 mitogen-activated protein kinase (MAPK), c-Jun N-terminal kinase 2 (JNK2), phosphoinositide 3-kinase (PI3K), and protein kinase B (PKB/AKT) were detected by immunohistochemistry. The diagnostic performance of the expression level of those molecules and their correlation with the elasticity characteristics were analyzed.

Results

Elasticity parameters and the expression levels of TGF- β1 and its signal molecules of benign lesions were lower than those of malignant lesions (P<0.0001). The expression levels of TGF- β1 and its signal molecules were correlated with elasticity parameters. The expression levels of TGF- β1 and its signal molecules in lesions with “stiff rim sign” were higher than those without “stiff rim sign” (P<0.05). And the expression levels of Smad2/3, Erk1/2, p38 MAPK, JNK2, PI3K and AKT were correlated with that of TGF- β1. The area under the curve for receiver operator characteristic curve of TGF-β1 and its signal molecules in the differentiation of malignant and benign breast lesions ranged from 0.920–0.960.

Conclusions

The expression levels of TGF-β1, its signal molecules of breast lesions showed good diagnostic performance and were correlated with the elasticity parameters. The expression levels of signal molecules were correlated with that of TGF- β1, which speculated that TGF- β1 might play an important role in the regulation of breast lesion elasticity parameters and multiple signal molecule expressions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-09036-4.

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.

Application of a shear-wave elastography prediction model to distinguish between benign and malignant breast lesions and the adjustment of ultrasound Breast Imaging Reporting and Data System classifications

AIM

To explore a real-time shear-wave elastography (SWE) prediction model distinguishing benign from malignant breast lesions and to determine its application in adjusting ultrasound Breast Imaging Reporting and Data System (BI-RADS) classifications.

MATERIALS AND METHODS

Four hundred and sixty-eight patients with 488 breast lesions were enrolled. Patients underwent hollow-needle puncture or surgical resection for histopathological examinations. Ultrasound examinations, both conventional ultrasound and real-time SWE, were performed <2 weeks prior to sampling. Statistical analyses were implemented to distinguish benign from malignant breast lesions and adjust ultrasound BI-RADS 3 and 4a classifications.

RESULTS

The real-time SWE indicators Emax and Ecol showed the highest diagnostic efficiency in distinguishing between benign and malignant lesions through quantitative and qualitative indicators, respectively. The area under the curve (AUC) for Emax was 0.837 while that for Ecol was 0.828. The AUC of the real-time SWE prediction model, constructed by multivariate logistic regression, for diagnosing benign and malignant breast lesions was 0.850.

CONCLUSION

The real-time SWE prediction model aids in the differential diagnosis of benign and malignant breast lesions but cannot replace conventional ultrasound. The model improves the diagnostic performance of ultrasound BI-RADS 3 and 4a classifications.

Comparative analysis of the quantitative parameter method and elasticity color mode method for real-time shear wave elastography in the diagnosis of benign and malignant solid breast lesions

OBJECTIVE

To examine the performance of real-time shear wave elastography (RT-SWE) in routine clinical practice.

METHODS

This was a prospective study of 500 patients. The elasticity color mode method was judged by a four-mode system. The quantitative parameter method was used to measure the modulus of elasticity of the lesions. Pathologic reports were used as a gold standard to comparatively analyze the diagnostic performance of the two methods.

RESULTS

A total of 553 tumors were detected. The average mode value and the modulus of elasticity (E_max) of the benign breast masses was lower than that of malignant masses (p < 0.05). With E_max = 67.4 as the diagnostic threshold value, the sensitivity, specificity, accuracy, negative predictive value, and positive predictive value of the two methods were not statistically significant different (p > 0.05).

CONCLUSIONS

The shear wave quantitative parameter method and the elasticity color mode method showed similar performances in the diagnosis of benign and malignant breast masses. The elasticity color mode method is convenient and intuitive, whereas the quantitative parameter method can be used to objectively assess the lesions when it is difficult to score the elasticity of an image, but could not be relied on alone.

TGF-β1: is it related to the stiffness of breast lesions and can it predict axillary lymph node metastasis?

Background

This study aimed to explore whether transforming growth factor β1 (TGF-β1) is correlated with the stiffness of breast lesions and if it can predict axillary lymph node (ALN) metastasis.

Methods

A retrospective analysis was performed in our hospital. A total of 135 breast lesions in 130 patients who were to undergo vacuum-assisted excisional biopsy (VAEB) or surgery were enrolled between April 2018 and October 2018. Ultrasound (US) and shear wave elastography (SWE) examinations were performed for every lesion before VAEB or surgery. Pathology results obtained by VAEB or surgery were regarded as gold criteria. The elastic parameters and TGF-β1 expression level of malignant breast lesions were compared with those of benign lesions; the relationship between TGF-β1 expression level in breast lesions and the elastic parameters was analyzed; the TGF-β1 expression level in breast lesions with or without ALN metastasis were compared; and the efficacy of TGF-β1 expression level in predicting ALN metastasis was analyzed.

Results

The malignant breast lesions were different from benign lesions in the maximum and mean elasticity (Emax, Emean), standard deviation of elasticity (ESD), elastic ratio of the lesions to the peripheral tissue (Eratio), and the occurrence rate of "stiff rim sign" (P<0.001). The expression level of TGF-β1 in benign breast lesions was significantly lower than that in malignant lesions (P<0.001), and the TGF-β1 expression level was positively correlated with Emax, Emean, ESD, and Eratio (r=0.869, 0.840, 0.834, and 0.734, respectively). The expression level of TGF-β1 in breast lesions with or without "stiff rim sign" was significantly different (P<0.001), and the TGF-β1 expression level in malignant breast lesions with ALN metastasis was significantly higher than that in malignant lesions without ALN metastasis (P=0.0009). When TGF-β1 expression level >0.3138 was taken as the cut-off value, its efficacy in predicting ALN metastasis was 0.853, with a sensitivity of 86.67%, and a specificity 83.33%.

Conclusions

The expression level of TGF-β1 was positively correlated with the elastic parameters of breast lesions, and it could be useful for predicting ALN metastasis, especially for negative ALN diagnosis clinically.

Can measuring perilesional tissue stiffness and stiff rim sign improve the diagnostic performance between benign and malignant breast lesions?

PURPOSE

To evaluate tissue stiffness values around breast lesions and stiff rim sign for the differentiation of benign and malignant lesions.

METHODS

A total of 192 patients (mean age, 44.6 ± 13.6 years) with 199 breast lesions were included in this retrospective study. All lesions were pathologically proven by US-guided core needle biopsy (CNB), Mammotome biopsy, or surgery. We first observed the presence or absence of a stiff rim sign, which was defined as a red or orange halo around the breast lesion. The shell around the breast lesion on SWE was then automatically drawn by machine, with a width of 1 mm, 2 mm, and 3 mm. The elasticity moduli of the lesion and surrounding tissue were recorded, including maximum elasticity (Emax), mean elasticity (Emean), minimum elasticity (Emin), and elasticity ratio (shell/lesion ratio). The optimal thresholds of elasticity moduli were calculated according to the receiver operating characteristic (ROC) curve.

RESULTS

There were 75 malignant lesions and 124 benign ones. The average Emax and Emean of lesions and shell were significantly higher in the malignant group than in the benign group (P < 0.05). The optimal cut-off value of Emax for diagnosing malignant lesions was 101.7 kPa, with a sensitivity of 66.3% and specificity of 87.9%. The optimal cut-off value of Emean was 29.1 kPa, with a sensitivity of 65.3% and specificity of 79.8%. The stiff rim sign had the highest diagnostic performance for malignancy as compared with other elastic parameters, with an accuracy of 88.4%. However, measuring peritumoral tissue stiffness can achieve relatively high sensitivity, whereas specificity was not improved significantly.

CONCLUSIONS

The stiffness of tissue surrounding breast malignancies was significantly higher than the surrounding benign lesions. Stiff rim sign has the potential to improve the diagnostic performance of breast lesions.

Combination of shear-wave elastography with ultrasonography for detection of breast cancer and reduction of unnecessary biopsies: a systematic review and meta-analysis

Purpose

This study was undertaken to compare the diagnostic performance and biopsy reduction rate of combined shear-wave elastography (SWE) and B-mode ultrasonography (US) versus B-mode US alone for breast lesions and to determine the most discriminatory parameter in SWE.

Methods

A systematic review and meta-analysis were conducted. The resources for the study were obtained from MEDLINE, Embase, Cochrane Library, and KoreaMed on August 17, 2018. The quality of the articles was evaluated using the Scottish Intercollegiate Guidelines Network (SIGN) tool.

Results

Twenty-five articles with 5,147 breast lesions were selected. The meta-analysis showed pooled sensitivities of 0.94 and 0.97 (P=0.087), pooled specificities of 0.85 and 0.61 (P=0.009), and area under the receiver operating characteristic curve (AUC) of 0.96 and 0.96 (P=0.095) for combined SWE and B-mode US versus B-mode US alone. When SWE was combined with B-mode US, the Breast Imaging Reporting and Data System category changed from 4 to 3 in 71.3% of the tests, decreasing the frequency of unnecessary biopsies by 41.1%. All four parameters of SWE (the color grade of lesion stiffness, maximum elasticity, mean elasticity, and color grade of lesion stiffness/homogeneity of the lesion) improved the specificity when they were added to B-mode US. The AUC for each SWE parameter was 0.99, 0.96, 0.96, and 0.93, respectively.

Conclusion

Adding SWE to B-mode US not only provides additional diagnostic information for differentiating between benign and malignant breast lesions, but also decreases the likelihood of unnecessary biopsies.

Value of quantitative sound touch elastography of tissues around breast lesions in the evaluation of malignancy

AIM

To assess the value of quantitative analysis of sound touch elastography of tissues around breast lesions to facilitate the evaluation of malignancy of the lesions.

MATERIALS AND METHODS

With the permission of the Ethics Committee, every patient signed informed consent forms before the study. One hundred and eighty-two solid breast lesions were analysed retrospectively. Postoperative histopathology proved that 63 lesions were malignant and 119 were benign. All lesions were examined by two-dimensional ultrasonography, colour Doppler ultrasonography and ultrasound elastography including sound touch elastography (STE) and strain elastography. Using pathological diagnosis as the reference, the correlation between each ultrasound marker and the malignancy of the solid breast masses was evaluated by chi-square test, and the logistic regression model was constructed to determine the best diagnostic model with multiple markers.

RESULTS

The areas under the receiver operating characteristic (ROC) curve (AUCs) of various elastography markers were compared and the markers with the largest AUC values, including quantitative, semi-quantitative, and distance markers were identified. Logistic regression analysis showed that the combination of accuracy of Breast Imaging Reporting and Data System (BI-RADS) classification + age + maximum elasticity value of the tissue around the lesion (EMax_shell) in predicting malignant lesions was higher than that of the other combinations. The prediction model verified that the sensitivity of diagnosis of the mammary lump was 94.12% and the specificity was 84.13%.

CONCLUSIONS

EMax_shell in the elasticity is the most valuable marker for the diagnosis of breast cancer, and age combined with EMax_shell can effectively improve the diagnostic efficacy of the BI-RADS classification in breast cancer.

Importance of shear-wave elastography in prediction of Achilles tendon rupture

PURPOSE

It was demonstrated that about 6% of patients with a ruptured Achilles tendon experience the rupture of contralateral tendon in the future; the aim of this study was to estimate the risk for rupture of contralateral tendon in patients who underwent surgical reconstruction of ruptured Achilles tendon by using subjective questionnaires and shear-wave elastography.

METHODS

Twenty-four patients who underwent surgical repair of the ruptured Achilles tendon and twelve age-matched healthy controls were examined with ultrasound SWE. Functional outcomes were assessed with American Orthopedic Foot and Ankle Society (AOFAS) scoring system and subjective rating system which we introduced and validated.

RESULTS

The elasticity of injured tendon was markedly decreased (by 42%) compared to the contralateral tendon of the patient, as expected. Both AOFAS score and our novel subjective assessment scale positively correlate with ultrasound SWE values in ruptured Achilles tendons. The elasticity of contralateral Achilles tendons in patients was 23% lower than among healthy individuals.

CONCLUSION

Irrespective of the lack of difference in the subjective feeling assessed by AOFAS, the contralateral tendon in the patients with reconstructed Achilles tendon has significantly lower stiffness than healthy individuals. Therefore, contralateral tendons in patients who suffered from rupture are more prone to future ruptures.

Breast sonoelastography: Now and in the future

PURPOSE

The purpose of this study was to identify practice trends and opinions concerning breast sonoelastography in two different health care systems, one in Europe (France) and the other in North America (Province of Québec/Canada).

MATERIALS AND METHODS

We distributed an 11-item online survey among French and Canadian breast radiologists. The survey comprised of four sections: (i) personal practice characteristics, (ii) breast sonoelastography usage in daily practice and evaluation of its usefulness, (iii) limitations and roles of sonoelastogrpahy in their clinical practice, and (iv) types of elastographic technique and interpretation.

RESULTS

We found that sonoelastography of the breast appears unpopular among Canadian radiologists, and poorly credible among French radiologists, who perceive it as an unreliable technique. To date, its real impact in clinical practice remains uncertain.

CONCLUSION

Continued learning and awareness of the indications, advantages and limitations of breast sonoelastography may motivate breast radiologists to adopt its use.