The present invention relates to a device for determining mechanical, particularly elastic, parameters of an examination object, comprising a) at least one arrangement for determining the spatial distribution of magnetic particles in at least one examination area of the examination object, comprising a means for generating a magnetic field with a spatial profile of the magnetic field strength such that there is produced in at least one examination area a first part-area having a low magnetic field strength and a second part-area having a higher magnetic field strength, a means for detecting signals which depend on the magnetization in the examination object, particularly in the examination area, that is influenced by a spatial change in the particles, and a means for evaluating the signals so as to obtain information about the, in particular temporally changing, spatial distribution of the magnetic particles in the examination area and b) at least one means for generating mechanical displacements, in particular oscillations, at least in and/or adjacent to the examination area of the examination object. The invention furthermore relates to a method for determining mechanical and/or physical parameters of an examination object, in particular using a device according to the invention. The invention further relates to magnetic particle compositions that can be used in that method according to the invention.Dispositif pour la détermination de paramètres mécaniques et plus particulièrement élastiques dun objet à examiner, comprenant: a) au moins un agencement pour déterminer la répartition spatiale de particules magnétiques dans au moins une zone dexamen de lobjet à examiner, comportant des moyens permettant de générer un champ magnétique présentant un profil spatial de lintensité du champ magnétique tel quune première sous-région de faible intensité et une deuxième sous-région dintensité de champ magnétique supérieure sont créées dans au moins une zone dexamen, des moye
