Multicenter Study of Ultrasound Real-Time Tissue Elastography in 779 Cases for the Assessment of Breast Lesions: Improved Diagnostic Performance by Combining the BI-RADS®-US Classification System with Sonoelastography

Purpose: Hitachi real-time tissue elastography (HI-RTE) is an ultrasound technique that facilitates the estimation of tissue elasticity. Our study evaluates whether sonoelastography improves the differentiation of benign and malignant breast lesions. Materials and Methods: In a multicenter approach sonoelastography of focal breast lesions was carried out in 779 patients with subsequent histological confirmation. We present data from 3 study centers (Berlin, Bielefeld, Homburg/Saar) focusing on the sensitivity (SE), specificity (SP) and the positive (PPV) and negative predictive value (NPV) of sonoelastography. In addition we performed an analysis of the diagnostic performance, expressed by the pretest and posttest probability of disease (POD), in BI-RADS (R)-US 3 or 4 lesions as these categories can imply both malignant and benign lesions and a more precise prediction would be a preferable aim. Results: Sonoelastography demonstrated an improved SP (89.5%) and an excellent PPV (86.8%) compared to B-mode ultrasound (76.1% and 77.2%). Especially in dense breasts ACR III-IV, the SP was even higher (92.8%). In BI-RADS-US 3 lesions, a suspicious elastogram significantly modified the POD from 8.3% to a posttest POD of 45.5%. In BI-RADS-US 4 lesions, we found a pretest POD of 56.6%. The posttest POD changed significantly to 24.2% with a normal elastogram and to 81.5% with a suspicious elastogram. Conclusion: Our data demonstrates that the complementary use of sonoelastography definitely improves the performance in breast diagnostics. Finally we present a protocol of how sonoelastography can be integrated into our daily practice.