Purpose: This study was undertaken to evaluate the value of quantitative elastography in the diagnosis of breast tumours.
Materials and methods: Conventional ultrasound (US) and quantitative elastography were performed in 108 women with 114 breast lesions by two experienced radiologists, and pathological results were available in all cases. For each lesion, the maximum, mean, and minimum (min) elasticity and elasticity ratio between lesions and surrounding tissue were measured. The Breast Imaging Reporting and Data System (BI-RADS) categories were assessed with conventional US in all lesions.
Results: Malignant lesions exhibited significantly higher maximum and mean elasticity (111.57 ± 69.29 kPa and 54.49 ± 33.70 kPa) than did benign lesions (59.00 ± 45.3 kPa and 36.64 ± 26.18 kPa) (p<0.01). For maximum elasticity versus BI-RADS, performance results were sensitivity 60.9 % vs. 78.3%, specificity 85.3% vs. 98.5%, positive predictive value (PPV) 73.7% vs. 97.3 %, negative predictive value (NPV) 76.3% vs. 87.0 % and accuracy 75.4% vs. 90.3%. BI-RADS had significantly better accuracy than maximum elasticity (p<0.01). Maximum and mean elasticity of invasive ductal carcinoma (IDC) were significantly higher than those of fibroadenoma (p<0.01), whereas the difference was not statistically significant with fibroadenosis, papilloma and inflammation (p>0.01). Maximum and mean elasticity and elasticity ratio of BI-RADS 5 were all significantly higher than those of BI-RADS 3 (p<0.01). Reliability for maximum and mean elasticity were almost perfect [intraclass correlation coefficients (ICC)=0.87 and 0.79].
Conclusions: Shear-wave elastography gives quantitative elasticity information that could potentially help in breast-lesion characterisation, although it cannot replace conventional BI-RADS in the differentiation of breast lesions.