Diagnostic performances of shear wave elastography: which parameter to use in differential diagnosis of solid breast masses?

Objective To evaluate which shear wave elastography (SWE) parameter proves most accurate in the differential diagnosis of solid breast masses. Methods One hundred and fifty-six breast lesions in 139 consecutive women (mean age: 43.54 ± 9.94 years, range 21–88 years), who had been scheduled for ultrasound-guided breast biopsy, were included. Conventional ultrasound and SWE were performed in all women before biopsy procedures. Ultrasound BI-RADS final assessment and SWE parameters were recorded. Diagnostic performance of each SWE parameter was calculated and compared with those obtained when applying cut-off values of previously published data. Performance of conventional ultrasound and ultrasound combined with each parameter was also compared. Results Of the 156 breast masses, 120 (76.9 %) were benign and 36 (23.1 %) malignant. Maximum stiffness (Emax) with a cut-off of 82.3 kPa had the highest area under the receiver operating characteristics curve (Az) value compared with other SWE parameters, 0.860 (sensitivity 88.9 %, specificity 77.5 %, accuracy 80.1 %). Az values of conventional ultrasound combined with each SWE parameter showed lower (but not significantly) values than with conventional ultrasound alone. Conclusions Maximum stiffness (82.3 kPa) provided the best diagnostic performance. However the overall diagnostic performance of ultrasound plus SWE was not significantly better than that of conventional ultrasound alone. Key Points • SWE offers new information over and above conventional breast ultrasound • Various SWE parameters were explored regarding distinction between benign and malignant lesions • An elasticity of 82.3 kPa appears optimal in differentiating solid breast masses • However, ultrasound plus SWE was not significantly better than conventional ultrasound alone