1 ) Process for simulation or for digital synthesis of sonographic images, characterized by the direct transformation in real time, or quasi-real time, of information contained in an MRI-type medical or veterinary image, without delimitation or segmentation of the organs or structures that are contained in the MRI image data volume, according to one or more two-dimensional observation windows that can be modified in real time, or quasi-real time, in dimension, in position, in direction and in orientation, whose characteristics are based on the type of a determined virtual sonographic probe and that reproduces all of the effects of attenuation, reflection, refraction and dispersion and effects of adjusting a real sonographic image, whereby each sonographic image that is provided accumulates the results of the simulations of the above-mentioned effects.