We present a Virtual Echographic System. Because this examination is particulary difficult, developping a simulator is very useful to give students some common databases of pathological samples on which they could experiment image acquisition and evaluate their understanding of clinical cases. We have applied our method to the simulation of thigh ultrasonographic examination for thrombosis diagnosis. A preliminary system, focusing on image generation, has been developped. Virtual echographic slices are generated using a particular interpolation technique and a deformation model of significant structures. Resulting images have a visual quality similar to usual ones.