Sonographic elastography combined with conventional sonography: How much is it helpful for diagnostic performance?

Objective. The purpose of this study was to evaluate the diagnostic performance of conventional sonography combined with sonographic elastography for differentiation between benign and malignant breast lesions and to assess the diagnostic performance with two types of interpretation criteria for sonographic elastography. Methods. For this study, we included 281 lesions from 267 patients that were diagnosed as benign or malignant by sonographically guided biopsy and prospectively analyzed by conventional sonography and sonographic elastography from October to December 2007. The histopathologic results from sonographically guided biopsy were used as a reference standard. The final assessments were made prospectively on the basis of conventional sonography alone and then by sonographic elastography combined with conventional sonography. The diagnostic performance using area under the receiver operating characteristic (ROC) curve analysis (A_z) was compared on the basis of conventional sonography alone and on elastography combined with conventional sonography. We also calculated the area ratio of lesions detected by elastography and the elasticity score reported by Itoh et al (Radiology 2006; 239:341-350). Results. The areas under the ROC curve for conventional sonography and the combination of conventional sonography and sonographic elastography were 0.927 and 0.876, respectively. The area ratio of the lesion had better diagnostic performance (A^z, 0.757) than the elasticity score (A ^z, 0.54; P < .05). Conclusions. The diagnostic performance of radiologists with respect to the characterization of breast masses as benign or malignant was not significantly improved with sonographic elastography. The area ratio of the lesion had a better diagnostic value in elastography than the elasticity score.