[Value of shear wave elastrography image classification in the diagnosis of breast masses]

Objective: To analyze the image features of shear wave elastrography (SWE) in breast masses, and to evaluate their values in the differentiation of benign and malignant breast lesions. Methods: A total of 361 patients with 403 breast lesions who simultaneously underwent conventional ultrasound and SWE examination from February 2015 to January 2018 were selected. Diagnosis in all patients was confirmed by aspiration biopsy or operative pathology. The SWE images were collected and the elastic images were divided into 5 types. The SWE image features of different breast pathological types were summarized, and their values in benign and malignant breast lesion diagnoses were evaluated. Results: The main features of benign breast lesion were type Ⅰ and Ⅱ, the main features of the malignant lesion were type Ⅳ and Ⅴ, and the proportion of which were 43.6% (71/163), 37.4% (61/163), 22.1% (53/240) and 57.9% (139/240), respectively. Type Ⅲ accounted for a certain proportion in both benign and malignant lesions. The SWE image features of benign and malignant lesions were compared and a significant difference was observed (P<0.001). The type Ⅴ features were mainly observed in invasive ductal carcinoma, invasive lobular carcinoma and other types of invasive carcinoma, while the type Ⅳ features were mostly presented in ductal carcinoma in situ and mucinous carcinoma. Fibroadenoma, fibroadenosis accompanied with fibroadenoma, and fibroadenosis were featured with type Ⅰ. Both intraductal papilloma and benign phyllodes tumor were mostly type Ⅱ, while type Ⅲ and Ⅴ were more common in chronic granulomatous mastitis. When type Ⅰ and typeⅡof breast lesions were classified as benign features while type Ⅳ and Ⅴ were malignant features, the sensitivity and specificity of breast malignant lesion diagnosis were 91.2% and 84.7% by application of SWE combined with breast imaging reporting and data system (BI-RADS). The sensitivity of combined diagnosis was slightly lower than that of conventional ultrasound (P>0.05), but the specificity was significantly higher than conventional ultrasound (P<0.01). Conclusion: The SWE is a simple and effective method. Combination of SWE with conventional ultrasound may improve the diagnostic differentiation of benign and malignant breast lesions.