The method involves simultaneously determining a position of a focal point (F2) of a treatment system (3) and positions of a target displacement unit and a treatment system displacement unit (30b). Displacement values for the displacement units are calculated from a virtual position of the target and positions of the focal point and displacement units to allow coinciding of the virtual position of the target with the focal point. The target and/or the focal point are displaced according to the calculated displacement values to make the virtual position of the target to coincide with the focal point. An independent claim is also included for an apparatus for locating and visualizing a target in a mammal with respect to a focal point of a treatment system.
