A-028 Ultrasound elastography
A. Athanasiou | Thursday, March 7, 16:00 – 17:30 / Room F2
Breast ultrasound elastography provides information about tissue elasticity Young modulus E = s / e, where s is the compression (stress) and e is the deformation (strain) of the tissue. It is a complementary tool to breast ultrasonography, easily performed in clinical practice. Two elasticity modes are currently available: strain imaging, where manual compression is applied to the ultrasound probe and tissue displacement is registered; tissue deformation is then calculated by means of dedicated software providing real-time elasticity images (color- or grey-coded) superimposed on B-mode imaging. This is a qualitative or semi-quantitative mode. Shear wave imaging, where US probe is used to induce mechanical vibrations using acoustic radiation force generating local tissue displacement. This mode provides quantitative information about either tissue displacement velocity or tissue stiffness itself in kPa. Functional information provided by elasticity imaging can be particularly useful for BIRADS 3 or 4a lesions. Various studies indicate that elasticity combined to B-mode imaging can improve breast ultrasound specificity up to 75-88%. False negative findings may be encountered in case of “soft” lesions (mucinous, medullary or cystic carcinomas) or inflammatory cancers. Differentiation between echogenic cysts and homogeneous solid lesions (such as fibroadenomas) can be improved as cystic features are usually specific in elasticity imaging. Iso-echoic lesions such as infiltrating lobular carcinomas may be better delimitated. Lymph-node characterization and microcalcification assessment can be improved, although few data are available and need further validation. 3D elastography is actually in progress and would be useful in monitoring response to neoadjuvant treatment.