Real-time ultrasound elastography of the breast: state of the art

Purpose: To review literature date on breast free hand elastography, while presenting typical examples of breast focal lesions displaying various types of Tsukuba elasticity scores. Background: Most of the breast cancers are more rigid than surrounding breast parenchyma. The principle of elastography relies on the relative resistance to movement of harder tissues compared to softer adjacent ones when slight pressure is applied. Procedure details and imaging findings: Sonoelastography demonstrates the elasticity of a lesion related to the elasticity of the surrounding tissue. The final result is based on the comparison between pre- and post compression data. According to the equipment type, various colors (256 hues) or gray shades are super imposed on 2D images. Stiff areas are coded in blue or dark gray tints, while softer, elastic tissues appear in red, green or bright shades of gray. The examples presented in this paper were acquired using a Hitachi 8500 US machine. The examination protocol was in accordance with Hitachi guidelines for elastography and final assessment was based on principles of Tsukuba elasticity score. Conclusions: Real-time breast ultrasound elastography is a fast, simple method which can improve the sensitivity and positive predictive value of conventional US when diagnosing BI-RADS 3 and 4 focal lesions. It can lead to a decreased rate of unnecessary biopsies or futile re-examinations. Elastography can provide information which is difficult or impossible to collect with conventional ultrasound alone, thus being an improved complementary method to be used along with other imaging modalities in breast diagnosis.