**1. Introduction**

No one denies anymore the use of ultrasound which is now part and parcel of the different techniques used in medical imagery for the diagnosis of mammary pathologies. The complementarity of these techniques (mammography, MR and ultrasound) is perfectly accepted, as each of them suffers from a certain number of shortcomings. The development of elastography has deeply improved the management of the monitoring of mammary lesions thanks to a better identification of the anomalies of the breast, a more accurate measuring of the lesions, a guiding of the biopsies of the lesions and of the lymph nodes, an approach to probably benign lesions, a management of those which are highly likely to be suspicious and a better planning of the surgical and therapeutic interventions. It is important to limit to the utmost the number of breast biopsies, when one bears in mind that between 40% and 50% of these biopsies concern benign lesions which, as a rule, do not require these punctures.

Echography (B-mode imagery-colour Doppler) can claim an excellent over 90% sensitivity, with a very good negative predictive value (NPV) (around 90%). But its specificity and its positive predictive value (PPV) are less accurate, by 40–60% according to various publications.

It is essential, when choosing an echography machine to select one with a good elastography attachment, as well as to have a minimum training to practice elastography so as to curb as much as possible the operator-dependent dimension of the examination, optimise the criteria of interpretation and finally ensure a good reproducibility of the results obtained.

It appears that the use of elastography has clearly contributed to limit the technical shortcomings of conventional echography. In order to achieve this, it is absolutely essential to abide by a minimum number of technical rules (like the correct positioning of the probe which must be horizontal and strictly perpendicular to the skin, as well as a good positioning of the patient in relation to the anatomical zones of the breast to be explored, and lastly a mastering of the micro-sismo-echography technique or vibrating technique or parkinson like vibrations (for Real Time Elastography Strain).

Though falling short of perfection, two important studies were commissioned in 2013 by EFSUMB (European Federation of the Societies of Ultrasound in Medicine and Biology): *Guidelines and Recommendations on the Clinical Use of Ultrasound Elastography* [1] and in 2015 by WFUMB (World Federation of Ultrasound in Medicine and Biology): *Guidelines and Recommendations for the Clinical Use of Ultrasound Elastography* [2]. Since these two dates, technical evolution as well as very numerous publications bear witness to very important improvements and a better approach to clinical applications for elastography.
