Role of Acoustic Shear Wave Velocity Measurement in Characterization of Breast Lesions

OBJECTIVES: To analyze the value of acoustic radiation force impulse imaging quantification in characterization of breast lesions and to analyze the stiffness of glandular and subcutaneous fatty tissue in benign and malignant lesions. METHODS: A total of 175 breast lesions (67 malignant and 108 benign) in 173 women were studied. With acoustic radiation force impulse imaging, shear wave velocity (SWV), which can reflect the stiffness of tissue, was measured within the lesion (internal SWV [SWVi]), in the boundary zone (boundary SWV [SWVb]), in normal-appearing glandular tissue (glandular SWV [SWVg]), and in subcutaneous fatty tissue (fatty SWV [SWVf]). All lesions underwent core needle biopsy or surgical excision. Differences among the SWV types in malignant and benign lesions were evaluated. We also assessed how different lesion types affected the SWV types. Receiver operating characteristic analysis was performed to assess the sensitivity and specificity of the SWV types in differentiating malignant from benign lesions. RESULTS: Internal SWV was significantly higher than SWVb, SWVg, and SWVf; SWVb was significantly higher than SWVg and SWVf; and SWVg was significantly higher than SWVf in both malignant and benign groups (P < .05). All 4 SWV types were significantly higher in the malignant group than the benign group (P < .05). In the malignant group, grade 3 invasive ductal carcinoma had the highest SWVi. The sensitivity and specificity for differentiating malignant lesions were 55.2% and 95.8% for SWVi, 85.1% and 53.3% for SWVb, 68.2% and 69.6% for SWVg, and 67.2% and 66.0% for SWVf. CONCLUSIONS: Acoustic radiation force impulse imaging has potential to characterize breast lesions, both internally and within the boundary zone, and to reflect changes in stiffness within surrounding glandular and subcutaneous fatty tissues caused by malignant tumors.