Most of existing technique need dedicated device for arterial stiffness evaluation and indirect calculation of intra arterial pressure. Supersonic Shear Imaging (SSI) is a novel non-invasive technique based on remote palpation of biological tissues that can image with very high temporal resolution (up to 10,000 images/s) and quantify the local viscoelastic properties of tissues. The investigators goal was to apply this SSI technique for arterial stiffness evaluation and local pulse wave velocity (PWV) calculation.