The present invention relates to a device for examination and use of an electrical field in a magnetic gradient field, containing magnetic particles in an examination area of an object under examination. The invention also relates to a method of determining the, especially three-dimensional, conductivity distribution in an examination area of an object under examination using a device according to the invention, a method for drug or active ingredient release, especially in locally targeted manner, in an examination area of an object under examination likewise using a device according to the invention, as well as use of a device according to the invention for electro-stimulation.
