Résumé:
As it allows to follow fast motion in the human body that remains undetectable for conventional echographic devices, ultrafast ultrasonic scanners should have a strong potential for upcoming medical imaging applications. Recently, such an ultrafast imaging system was built and applied to breast tumor detection. By providing quantitative mapping of the shear elasticity of soft tissues, this system should replace the subjective palpation of the physician. The ultrafast Scanner provides speckle images of tissues with frame rates 200 times higher than conventional scanners. It allows to detect fast tissue motion induced by low frequency shear waves generated inside the body using an external mechanical vibrator. As their propagation speed is related to the local shear elasticity of the medium, an elasticity map can be performed using inversion algorithms. Preliminary in vivo results in breast demonstrate that this technique, called transient elastography, is very sensitive to the presence of hard tumors.

Mots-clés: Ultrasound, Transient elastography, Breast cancer, Shear waves, Young's modulus