Breast Sonography - 2D, 3D, 4D Ultrasound or Elastography?

SUMMARY: The aim of this publication is to give an answer to the question whether 2D, 3D and 4D sonography of the breast can be replaced by elastography or whether elastography is an adjunct tool to B-mode imaging. The Breast Imaging and Reporting Data System (BI-RADS) ultrasound (US) descriptors of a lesion besides vascularity are based on B-mode imaging. US elastography displays the mechanical tissue properties. This information can be obtained by freehand compression and decompression. Acoustic radiation force impulse imaging (ARFI) produces stress with low-frequency push pulses. Manual compression by the transducer is not necessary. Shear wave elastography (SWE) is the combination of ARFI and the measurement of the consecutive shear wave propagations in the tissue. A quantification of the elasticity in kilopascal (kPa) is offered. Discussing B-mode imaging and elastography combined with the literature, elastography is seen as an addition to B-mode imaging with the potential to increase the specificity of the B-mode imaging-based BI-RADS assessment. In spite of additional elasticity information, the sensitivity remains high. A time-saving diagnostic algorithm for 2D, 3D US and elastography is described. In conclusion, it must be said that elasticity is not a stand-alone US modality able to replace 2D and 3D sonography.