The present invention concerns a method and a medical apparatus for visualizing on MR-images a hadron beam path traversing an organic body. The present method takes advantage of artefacts in MR-image acquisition provoked by the changes in properties of excitable atoms when irradiated by a hadron beam. By carefully synchronizing the hadron pulses with different steps of MR-data acquisition, it is possible to identify such artefacts and determine from their positions the hadron beam path and the corresponding position of the Bragg peak.
