Benign lesion evaluation: Factors causing the "Stiff Rim" Sign in Breast Tissues using Shear-wave Elastography.

Objective: To investigate the factors causing the "stiff rim" sign in breast lesions using shear-wave elastography. Methods: A total of 907 patients with 907 lesions were included retrospectively in this study. Traditional ultrasound and shear-wave elastography imaging were both performed. Patients age, maximum diameter, depth, distance, echogenicity, shape, boundary, margin, internal components, CDFI, calcification, echogenicity attenuation and longitudinal growth of lesions were observed and calculated by both univariate and multivariate analyses. Results: Univariate analyses indicated that the age, depth, shape, margin, internal components, CDFI, calcification and pathology showed significant difference between the benign lesions with and without a "stiff rim", whereas there was no correlation of "stiff rim" with maximum diameter, distance, boundary, echogenicity, echo attenuation and longitudinal growth of the lesions. Multivariate analysis expressed that CDFI, margin, internal components, depth and age were significantly associated with the "stiff rim" sign in breast benign lesions, whereas there was no correlation with the pathology, shape or calcification of the lesions. Conclusions: The "stiff rim" sign can be helpful for differentiation between benign and malignant lesions. Older patients with a "stiff rim" sign whose benign masses are deep, poorly defined, heterogeneous and have a positive CDFI should be examined more closely to avoid unnecessary false-positives. Advances in knowledge: The "stiff rim" sign can be helpful for differentiation between benign and malignant lesions. Positive CDFI, poorly defined margin, heterogeneous internal components, deep depth and older age were significantly associated with the "stiff rim" sign in benign breast lesions.