The invention concerns a medical imaging station including segmentation means for segmenting at least one imaged object in an image having gray levels, by propagating an edge from at least one initial point positioned in the image on the imaged object. The speed of propagation of the edge depends on said gray levels at each point referred to as a current point and the segmentation means segmenting the image between the points over which the edge passes and the points over which the edge does not pass. According to the invention, the edge propagation means are coupled with means of automatically detecting an emergence of the propagation edge from the imaged object at a current point. Means of locally fixing the speed of propagation at zero at this current point are activated in the event of detection of an emergence of the propagation edge.