Diagnostic value of strain elastography and shear wave elastography in differentiating benign and malignant breast lesions
Rafia Shahzad, Ismat Fatima, Tooba Anjum, Abubaker Shahid
Abstract
BACKGROUND: Conventional B-mode breast ultrasonography, though the primary modality to determine benign or malignant nature of a solid breast lesion, sometimes encounters overlapping sonographic morphological features in a single lesion. Elastography leads to improvement by evaluating the structural aspects and characterization of the lesion as benign or malignant on the basis of multi-parametric assessment. OBJECTIVE: Determine the role of strain elastography (SE) and shear wave elastography (SWE) in differentiating benign and malignant breast lesions. DESIGN: Cross sectional SETTING: Radiology department of hospital PATIENTS AND METHODS: Patients meeting inclusion criteria referred to our hospital for ultrasonography followed by biopsy or surgical excisions were examined with B-mode ultrasonography and by both strain and shear wave elastography. MAIN OUTCOME MEASURES: Mean values of SE and SWE in benign and malignant breast lesions, determination of cutoff using AUC curves and sensitivity and specificity of both techniques. SAMPLE SIZE: One hundred breast lesions from 95 consecutive patients. RESULTS: <.001). Assigning 45.3 as a cut off value provided a sensitivity of 95.8% with a specificity of 85.7%; the positive predictive value was 94.5% and the negative predictive value was 89.6%. The Breast Imaging Reporting and Data System (BI-RADS) category alone was able to differentiate between benign and malignant lesions with a sensitivity of 91.7% and a specificity 100% keeping the cut off value between 4a and 4b. The area under the ROC curve was 0.979. Combining the three (BI-RADS + SE + SWE) distinguished benign vs. malignant lesions with a sensitivity up to 100% and specificity up to 96.3%. CONCLUSION: Combining SE and SWE as a complementary tool with conventional B-mode ultrasonography has a significant potential for better characterization of solid breast lesions and decreasing unnecessary biopsies of BI-RADS IVa lesions. LIMITATIONS: Single institution study. CONFLICT OF INTEREST: None.