| Objective：Shear wave elastography (SWE) is a new method of obtaining quantitative tissueelasticity data during breast ultrasound (US) examinations. The aims of this study wereto determine the appearance of breast tissues (glandular, fatty and a series of solid breastmasses) at quantitative ultrasonographic elastography and to assess the correlationbetween quantitative values of lesion stiffness and pathologic results, which were usedas the reference standard. We therefore evaluated the diagnostic performance of SWEfor the differentiation of breast masses.Materials and methods:1. Conventional US and SWE were performed in210women with270breast lesionswho had been scheduled for US-guided core biopsy or surgical excision. Thefeatures of sonographic images including lesion’s shape, margin, echo, height/width,halo, acoustic shadow, flow, which were classified according to the AmericanCollege of Radiology (ACR) Breast Imaging Reporting and Data System(BI-RADS). The quantitative elasticity values of the lesions were measured, andreceiver operating characteristic (ROC) curves were used to assess diagnosticperformance which were used as the reference standard..2. SWE were performed in227women with healthy glandular and in102women withfatty. The quantitative elasticity values were measured and compared betweenbenign and malignant masses using statistical analysis.3. BI-RADS categoriesⅡ, Ⅲ and Ⅳa were taken as benign while BI-RADS categoriesⅣb, Ⅳc and Ⅴwere taken as malignant. To evaluate diagnostic performance (sensitivity, specificity and accuracy) and the performance of established BI-RADScategories and elasticity values and combined both BI-RADS and SWE.Results:1. There were198benign lesions in147patients and72malignant lesions in63patients. The maximum elasticity value of malignant lesions was (116.39±59.02)kPa, the mean value was (54.60±30.73) kPa and the minimum value was (23.54±18.89) kPa, whereas of benign ones was (42.32±31.55) kPa,(25.57±16.25) kPaand14.35±9.41kPa, whereas of glandular ones was (21.74±9.62)kPa,(14.75±6.26)kPa and (10.02±4.68)kPa, whereas of fatty ones was (12.50±5.23)kPa,(7.86±2.58)kPa and (5.4±2.00)kPa,respectively （P＜0.05).2. The area under the ROC curve (AUC) of the maximum, mean and minimumelasticity value was0.889,0.832and0.659, respectively. The diagnosticperformance of the maximum and mean elasticity value was higher than the one ofminimum elasticity value （P＜0.05）.3. Taking66.8kPa as the threshold of the maximum elasticity value, the sensitivity,specificity and accuracy were83.3%,86.9%and85.9%.Taking41.2kPa as thethreshold of the mean elasticity value, the sensitivity, specificity and accuracy were62.5%,89.4%and82.2%. Taking14.9kPa as the threshold of the minimum elasticityvalue, the sensitivity, specificity and accuracy were66.7%,66.2%and66.3%.Theconventional US performance figures were sensitivity91.7%, specificity81.3%andaccuracy84.1%.4. By combining both BI-RADS and SWE, the sensitivity, specificity and accuracy ofthe maximum value combined, the mean value combined and the minimum valuecombined were98.6%,72.7%and79.6%,98.6%,74.7%and81.1%,97.2%,57.6%and68.1%, respectively. The sensitivity of combining the two methods was higherthan SWE or US(P≤0.05). Conclusion:1. SWE provides quantitative information about the local viscoelastic properties of thebreast tissue, which is highly reproducible. The quantitative elasticity measurementscan be useful for characterizing breast lesions and reflect the histopathologicfeatures, which could help in the ultrasonic tissue characterization study.2. SWE has the potential to aid in the differentiation of benign and malignant breastlesions. The optimal cut-off the maximum value and mean value was66.8kPa and41.2kPa, respectively, the specificity and accuracy was highly.3. SWE combined with US could improve the diagnostic sensitivity and it can assistthe detection and the diagnosis of breast cancer which has a significant value ofclinical application. |
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