Purpose:
To determine the sensitivity and specificity of a real-time elasticity imaging (EI) ultrasound (US) system in the characterization of breast lesions as benign or malignant.
Methods:
A total of 208 patients with 251 lesions were scheduled to undergo a US-guided breast biopsy for a mass identified on B-mode US, and each received a real-time elasticity image of the lesion before the biopsy. The lesion size measurements were obtained, and the EI/B-mode size ratio was obtained. The pathology report was obtained and correlated with the EI/B-mode ratio. An EI/B-mode ratio equal to or greater than 1 was considered malignant lesion, whereas EI/B-mode ratios of less than 1 were considered benign. Sensitivity, specificity, positive predictive values, and negative predictive values were calculated.
Results:
Of the 251 lesions biopsied, 197 were pathologically benign, and 54 were malignant. Of the 54 malignant lesions, all had an EI/B-mode ratio equal to or greater than 1. Of the 197 benign lesions, 187 had an EI/B-mode ratio of less than 1. Ten benign lesions had an EI/B-mode ratio of greater than 1. The benign lesions that had an EI/B-mode ratio of greater than 1 were lesions with dense fibrosis, and in addition, a characteristic artifact was identified, which was visualized in all simple and complex cysts. The results correspond with a sensitivity of 100%, specificity of 95%, a positive predictive value of 84%, and a negative predictive value of 100%.
Conclusions:
Initial results of a real-time EI system for characterization of breast lesions suggest this technique can provide significant new diagnostic information. As a result, this information may significantly improve the ability to select patients for breast biopsy, resulting in a reduction in the number of benign breast biopsies.
Abbreviations: EI = elasticity imaging
