Two-dimensional shear wave elastography for differential diagnosis between mastitis and breast malignancy.

OBJECTIVE: To determine the diagnostic performance of conventional ultrasound (US) and two-dimensional shear wave elastography (2D SWE) in the differential diagnosis between mastitis and breast malignancy. METHODS: Between January 2016 and March 2017, 105 patients with 105 pathologically proven breast lesions were enrolled. All the lesions were subject to conventional US and 2D SWE examinations. In 2D SWE, the qualitative parameter of stiff rim sign and quantitative parameter of maximal shear wave velocity (SWV) were obtained. The diagnosis performances of US and combination of US and 2D SWE were evaluated, including sensitivity, specificity and the area under the receiver operating characteristic curve (AUROC). The AUROC of US and the combined method were also evaluated in subgroups with different diameters. RESULTS: Pathologically, 26 breast lesions were confirmed to be mastitis and 79 were malignant. The cut-off value for maximal SWV was 6.75 m/sec. The AUROC of stiff rim sign and maximal SWV were 0.701 (95% CI: 0.587-0.815) and 0.753 (95% CI: 0.659-0.832) respectively. Compared with US, the specificity and AUROC of the combined method increased significantly (specificity: 11.5% vs. 96.1%, AUROC: 0.520 vs. 0.752; both P < 0.05). CONCLUSIONS: The combination of US and 2D SWE improved the diagnostic performance in the differential diagnosis between mastitis and breast malignancy in comparison with the conventional US alone.