Role of shear-wave elastography (SWE) in complex cystic and solid breast lesions in comparison with conventional ultrasound

Chronic mastitis manifest as complex breast cyst in ultrasound and the role of elastography: A case series

This case series aims to describe the clinical presentation of mastitis, the conventional sonography and elastography findings, and histopathological features in the diagnosis of chronic mastitis. We present 3 cases of breast swelling in young ladies with one of the cases is related to breastfeeding with similar imaging appearance of complex breast cyst and the histopathology finding of chronic mastitis. We will describe the role of elastography in evaluating and differentiating the benign and malignant complex breast cyst.

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.

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.

Reducing Unnecessary Biopsy of Breast Lesions: Preliminary Results with Combination of Strain and Shear-Wave Elastography

The aim of our study was to compare strain elastography (SE), acoustic radiation force impulse-inducing Virtual Touch Imaging ([VTI] Siemens Medical Solutions, Mountain View, CA, USA), Virtual Touch Imaging Quantification ([VTIQ] Siemens Medical Solutions) and combined methods in the evaluation of ultrasound (US) Breast Imaging-Reporting and Data System (BI-RADS) category 4 lesions to explore an applicable way to reduce unnecessary biopsy by reducing false positives of conventional US without yielding false-negative cases. A total of 267 patients with 278 BI-RADS category 4 lesions (151 benign and 127 malignant) were evaluated with conventional B-mode US, SE, VTI and VTIQ implemented on a Siemens Acuson S2000 US system. Diagnostic performance, including area under the receiver operating characteristic curve, sensitivity, specificity, accuracy, positive predictive value (PPV) and negative predictive value (NPV) were evaluated. Overall, VTI alone exhibited the highest NPV (91.74%), although combined elastic methods exhibited higher NPV than single methods, with the highest NPV at 100% when the VTI, SE and VTIQ methods were combined. Compared with conventional US, PPV increased from 45.7% (127 of 278) to 63.18% (127 of 201) when adding combined elastography (VTI + SE +VTIQ). In addition, 52.5% (63/120) and 50.8% (61/120) of BI-RADS 4 A lesions were downgraded when using combined methods (VTI + SE and VTI + SE + VTIQ, respectively) without missing any cancer. However, 2 intraductal papillomas and 1 phyllodes tumor were not identified. In conclusion, the combination of different elastic methods have the potential to downgrade BI-RADS 4A lesions to reduce false-positive biopsies without increasing the risk of missing cancers.

Comparative Diagnostic Accuracy of Contrast-Enhanced Ultrasound and Shear Wave Elastography in Differentiating Benign and Malignant Lesions: A Network Meta-Analysis

Background: We performed a network meta-analysis to compare the diagnostic accuracy of contrast-enhanced ultrasound (CEUS) and shear wave elastography (SWE) in differentiating benign and malignant lesions in different body sites.

Methods: A computerized literature search of Medline, Embase, SCOPUS, and Web of Science was performed using relevant keywords. Following data extraction, we calculated sensitivity, specificity, positive likelihood ratio (LR), negative LR, and diagnostic odds ratio (DOR) for CEUS, and SWE compared to histopathology as a reference standard. Statistical analyses were conducted by MetaDiSc (version 1.4) and R software (version 3.4.3).

Results: One hundred and fourteen studies (15,926 patients) were pooled in the final analyses. Network meta-analysis showed that CEUS had significantly higher DOR than SWE (DOR = 27.14, 95%CI [2.30, 51.97]) in breast cancer detection. However, there were no significant differences between CEUS and SWE in hepatic (DOR = −6.67, 95%CI [−15.08, 1.74]) and thyroid cancer detection (DOR = 3.79, 95%CI [−3.10, 10.68]). Interestingly, ranking analysis showed that CEUS achieved higher DOR in detecting breast and thyroid cancer, while SWE achieved higher DOR in detecting hepatic cancer. The overall DOR for CEUS in detecting renal cancer was 53.44, 95%CI [29.89, 95.56] with an AUROC of 0.95, while the overall DOR for SWE in detecting prostate cancer was 25.35, 95%CI [7.15, 89.89] with an AUROC of 0.89.

Conclusion: Both diagnostic tests showed relatively high sensitivity and specificity in detecting malignant tumors in different organs. Network meta-analysis showed that CEUS had higher diagnostic accuracy than SWE in detecting breast and thyroid cancer, while SWE had higher accuracy in detecting hepatic cancer. However, the results were not statistically significant in hepatic and thyroid malignancies. Further head-to-head comparisons are needed to confirm the optimal imaging technique to differentiate each cancer type.

Complex cystic and solid breast lesions: Diagnostic performance of conventional ultrasound, strain imaging and point shear wave speed measurement

OBJECTIVE

To assess the performance of conventional high frequency ultrasound (US) and US elastography in diagnosis of complex cystic and solid breast lesions.

METHODS

Ninety three lesions in 93 patients underwent conventional US and US elastography, including strain elastography, acoustic radiation force impulse (ARFI) imaging, and point shear wave speed (SWS) measurement.

RESULTS

Pathological examination revealed 31 (33.3%) of the 93 lesions were malignant and the remaining 62 (66.7%) were benign. Multivariate analysis showed that elder patient (OR: 25.301), internal vascularity (OR: 4.518), and not circumscribed margin (OR: 3.813) were independent predictors for malignancy, while predominately cystic lesions (OR: 0.178) was a predictor for benign lesions (all p < 0.05). Invalid SWS measurement was occurred in 19 of 31 (61.3%) malignant lesions and 16 of 62 (25.8%) benign lesions, respectively (p < 0.05). The mean SWS value for malignant lesions was significantly lower than that for benign ones, being 1.60±0.63 m/s (range, 0.68-2.70 m/s) versus 2.33±0.77 m/s (range, 0.67-3.97 m/s) (p < 0.05). Areas under the ROC curve (Azs) for Breast Imaging Reporting and Data System (BI-RADS) assessment, strain elasticity score, ARFI imaging and valid point SWS measurement were 0.844, 0.734, 0.763 and 0.778,respectively.

CONCLUSIONS

US BI-RADS category, strain elastography score, ARFI imaging patterns and point SWS measurement are useful for malignancy prediction of complex cystic and solid breast lesions. The result that SWS for malignant lesions is lower than benign one should be carefully interpreted since invalid SWS measurement is excluded for analysis. The true stiffness of malignant cystic and solid lesions should be further evaluated with a new generation of two-dimensional SWS imaging.

Ex Vivo Shear-Wave Elastography of Axillary Lymph Nodes to Predict Nodal Metastasis in Patients with Primary Breast Cancer

Purpose

There is still a clinical need to easily evaluate the metastatic status of lymph nodes during breast cancer surgery. We hypothesized that ex vivo shear-wave elastography (SWE) would predict precisely the presence of metastasis in the excised lymph nodes.

Methods

A total of 63 patients who underwent breast cancer surgery were prospectively enrolled in this study from May 2014 to April 2015. The excised axillary lymph nodes were examined using ex vivo SWE. Metastatic status was confirmed based on the final histopathological diagnosis of the permanent section. Lymph node characteristics and elasticity values measured by ex vivo SWE were assessed for possible association with nodal metastasis.

Results

A total of 274 lymph nodes, harvested from 63 patients, were examined using ex vivo SWE. The data obtained from 228 of these nodes from 55 patients were included in the analysis. Results showed that 187 lymph nodes (82.0%) were nonmetastatic and 41 lymph nodes (18.0%) were metastatic. There was significant difference between metastatic and nonmetastatic nodes with respect to the mean (45.4 kPa and 17.7 kPa, p<0.001) and maximum (55.3 kPa and 23.2 kPa, p<0.001) stiffness. The elasticity ratio was higher in the metastatic nodes (4.36 and 1.57, p<0.001). Metastatic nodes were significantly larger than nonmetastatic nodes (mean size, 10.5 mm and 7.5 mm, p<0.001). The size of metastatic nodes and nodal stiffness were correlated (correlation coefficient of mean stiffness, r=0.553). The area under curve of mean stiffness, maximum stiffness, and elasticity ratio were 0.794, 0.802, and 0.831, respectively.

Conclusion

Ex vivo SWE may be a feasible method to predict axillary lymph node metastasis intraoperatively in patients undergoing breast cancer surgery.

Virtual touch tissue imaging and quantification: value in malignancy prediction for complex cystic and solid breast lesions

This study was aimed to evaluatethe usefulness of conventional ultrasound (US) and US elastography, including the latest virtual touch tissue imaging and quantification (VTIQ), in malignancy prediction for complex cystic and solid breast lesions. Eighty-nine complex cystic and solid breast lesions were subject to conventional US and US elastography, including strain elastography (SE), virtual touch tissue imaging (VTI) and VTIQ. Among the 89 lesions, thirty-four (38.2%) lesions were malignant and 55 (61.8%) lesions were benign. Sixteen variables were subject to multivariate logistic regression analysis. Pattern 4b in VTI (odds ratio, OR:15.278), not circumscribed margin of lesion (OR:12.346), SWS mean >4.6 m/s in VTIQ (OR:11.896), and age elder than 50 years (OR:6.303) were identified to be independent predictors for malignancy. In receiver operating characteristic (ROC) curve analyses, associated areas under the ROC curve (Az) for conventional US could be significantly elevated, from 0.649 to 0.918, by combining with US elastography (p < 0.0001). The combined diagnostic method was able to improve the specificity (32.7% vs. 87.3%, p < 0.0001) without sacrificing the sensitivity (97.1% vs. 85.3%, p = 0.075). Both conventional US and US elastography contribute substantially to malignancy prediction in complex cystic and solid lesions. The diagnostic efficacy of conventional US in terms of Az and specificity could be significantly improved by combining with US elastography.

Shear-Wave Elastography for the Differential Diagnosis of Breast Papillary Lesions

OBJECTIVE

To evaluate the diagnostic performance of shear-wave elastography (SWE) for the differential diagnosis of breast papillary lesions.

METHODS

This study was an institutional review board-approved retrospective study, with a waiver of informed consent. A total of 79 breast papillary lesions in 71 consecutive women underwent ultrasound and SWE prior to biopsy. Ultrasound features and quantitative SWE parameters were recorded for each lesion. All lesions were surgically excised or excised using an ultrasound-guided vacuum-assisted method. The diagnostic performances of the quantitative SWE parameters were compared using the area under the receiver operating characteristic curve (AUC).

RESULTS

Of the 79 lesions, six (7.6%) were malignant and 12 (15.2%) were atypical. Orientation, margin, and the final BI-RADS ultrasound assessments were significantly different for the papillary lesions (p < 0.05). All qualitative SWE parameters were significantly different (p < 0.05). The AUC values for SWE parameters of benign and atypical or malignant papillary lesions ranged from 0.707 to 0.757 (sensitivity, 44.4-94.4%; specificity, 42.6-88.5%). The maximum elasticity and the mean elasticity showed the highest AUC (0.757) to differentiate papillary lesions.

CONCLUSION

SWE provides additional information for the differential diagnosis of breast papillary lesions. Quantitative SWE features were helpful to differentiate breast papillary lesions.

Lipotransfer for radiation-induced skin fibrosis

BACKGROUND

Radiation-induced fibrosis (RIF) is a late complication of radiotherapy that results in progressive functional and cosmetic impairment. Autologous fat has emerged as an option for soft tissue reconstruction. There are also sporadic reports suggesting regression of fibrosis following regional lipotransfer. This systematic review aimed to identify cellular mechanisms driving RIF, and the potential role of lipotransfer in attenuating these processes.

METHODS

PubMed, OVID and Google Scholar databases were searched to identify all original articles regarding lipotransfer for RIF. All articles describing irradiated fibroblast or myofibroblast behaviour were included. Data elucidating the mechanisms of RIF, role of lipotransfer in RIF and methods to quantify fibrosis were extracted.

RESULTS

Ninety-eight studies met the inclusion criteria. A single, definitive model of RIF is yet to be established, but four cellular mechanisms were identified through in vitro studies. Twenty-one studies identified connective tissue growth factor and transforming growth factor β1 cytokines as drivers of fibrotic cascades. Hypoxia was demonstrated to propagate fibrogenesis in three studies. Oxidative stress from the release of reactive oxygen species and free radicals was also linked to RIF in 11 studies. Purified autologous fat grafts contain cellular and non-cellular properties that potentially interact with these processes. Six methods for quantifying fibrotic changes were evaluated including durometry, ultrasound shear wave elastography, thermography, dark field imaging, and laser Doppler and laser speckle flowmetry.

CONCLUSION

Understanding how lipotransfer causes regression of RIF remains unclear; there are a number of new hypotheses for future research.

Diagnostic value of two-dimensional shear wave elastography in papillary thyroid microcarcinoma

Objective

The purpose of this study was to evaluate the predictability of two-dimensional shear wave elastography (2D-SWE) for papillary thyroid microcarcinoma (PTMC).

Materials and methods

One hundred and eighteen patients with 137 thyroid nodules (46 benign nodules, 91 malignant nodules) were included in this study who received conventional ultrasound (US) and 2D-SWE before fine-needle aspiration or surgery. The diagnostic performance was compared between US findings only and the combined use of US findings with 2D-SWE, which were correlated with pathology results.

Results

Receiver-operating characteristic curve analysis was performed to assess the diagnostic performance of 2D-SWE. Conventional US findings and 2D-SWE values were analyzed and compared between benign and malignant thyroid nodules. The mean values of SWE_mean, SWE_min, and SWE_max were 46.6±16.7, 26.2±9.5, and 73.6±18.1 kPa, respectively, in PTMC, which were significantly higher than those in benign tumors (27.8±12.4, 15.8±8.6, and 50.3±22.6 kPa, P<0.001). The optimal cut-off values of SWE_mean, SWE_min, and SWE_max for predicting malignancy were 34.5, 21.8, and 53.2 kPa, respectively. Taller than wide, micro-calcification, and SWE_mean were found to be independent risk factors for predicting PTMC. The overall sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of combined conventional US features with 2D-SWE parameters were 95.7%, 94.5%, 94.9%, 89.8%, and 97.7%, respectively; these were superior to those of conventional US (89.1%, 90.1%, 89.9%, 82.0%, and 93.2%).

Conclusion

The study indicates that the quantitative parameters of 2D-SWE are an independent predictive factor for diagnosing PTMC, which could provide valuable information when conventional US cannot give determinate results.