Differential diagnosis of idiopathic granulomatous mastitis and breast cancer using acoustic radiation force impulse imaging.

Abstract

Differentiation of idiopathic granulomatous mastitis (IGM) from carcinoma with routine imaging methods, such as ultrasonography (US) and mammography, is difficult. Therefore, we evaluated the value of a newly developed noninvasive technique called acoustic radiation force impulse imaging in differentiating IGM versus malignant lesions in the breast. Four hundred and eighty-six patients, who were referred to us with a presumptive diagnosis of a mass, underwent Virtual Touch tissue imaging (VTI; Siemens) and Virtual Touch tissue quantification (VTQ; Siemens) after conventional gray-scale US. US-guided percutaneous needle biopsy was then performed on 276 lesions with clinically and radiologically suspicious features. Malignant lesions (n=122) and IGM (n=48) were included in the final study group. There was a statistically significant difference in shear wave velocity marginal and internal values between the IGM and malignant lesions. The median marginal velocity for IGM and malignant lesions was 3.19m/s (minimum-maximum 2.49-5.82) and 5.05m/s (minimum-maximum 2.09-8.46), respectively (p<0.001). The median internal velocity for IGM and malignant lesions was 2.76m/s (minimum-maximum 1.14-4.12) and 4.79m/s (minimum-maximum 2.12-8.02), respectively (p<0.001). The combination of VTI and VTQ as a complement to conventional US provides viscoelastic properties of tissues, and thus has the potential to increase the specificity of US.