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.
Keywords: Breast; Doppler; Elastography; Non-mass lesion; Shear wave.