Additional diagnostic value of shear-wave elastography and color Doppler US for evaluation of breast non-mass lesions detected at B-mode US

Objective: To evaluate the diagnostic value of shear-wave elastography (SWE) and colour Doppler ultrasound (US) for evaluation of breast non-mass lesions (NMLs) detected by B-mode US. Methods: This retrospective study enrolled 116 NMLs (42 benign, 74 malignant). For each lesion, B-mode US, SWE and colour Doppler US were performed. Mean elasticity (E_mean), maximum elasticity (E_max) and vascularity were assessed by SWE and Doppler US. Diagnostic performances of B-mode US, SWE and Doppler US were calculated to differentiate benign and malignant NMLs. Results: In benign NMLs, average E_mean and E_max were lower, and low vascularity (no flow or only one vessel flow) was more frequent (P < 0.001). When BI-RADS category 4a NMLs were downgraded to category 3 with ‘E_mean of 85.1 kPa or less’ and/or ‘low vascularity’, specificities increased (69.0–90.5 %; P < 0.001), without significant loss in sensitivities (97.3–100 %). When these 4a NMLs were downgraded by the combination of SWE and Doppler US, all downgraded NMLs (59.3 %, 19/32) were confirmed as benign. Conclusions: Addition of SWE and colour Doppler US to B-mode US improved diagnostic performances in differentiating benign and malignant NMLs. This study suggests that the combination of SWE and colour Doppler may help patients with BI-RADS category 4a NMLs avoid unnecessary biopsies. Key Points: • B-mode US features of malignant and benign NMLs may overlap. • SWE and colour Doppler provides useful information about breast NMLs. • SWE and colour Doppler may decrease unnecessary biopsies of breast NMLs.