eliminating time invariable influences shim plates of ferromagnetic material are attached at suitable locations time variable influences are eliminated by shim coils 2 that are driven by a shim power supply 15 a cylindrical gradient coil system 3 is built into the basic field magnet 1 the system 3 being composed of three sub windings each sub winding is supplied with current by an amplifier 14 for generating a linear gradient field in the respective directions of a cartesian coordinate system the first sub winding of the gradient field system 3 generates a gradient g x in the x direction the second sub winding generates a gradient g y in the y direction and the third sub winding generates a gradient g z in the z direction each amplifier 14 has a digital to analog converter dac that is driven by a sequence control 18 for the time controlled generation of gradient pulses a radio frequency antenna 4 is situated within the gradient field system 3 the antenna 4 converts the radio frequency pulses emitted by a radio frequency power amplifier into an alternating magnetic field for exciting the nuclei and aligning the nuclear spins of the subject under examination or of a region of the subject under examination the radio frequency antenna 4 is composed of one or more rf transmission coils and a number of rf reception coils in the form of an arrangement preferably linear of component coils the alternating field proceeding from the processing nuclear spins i e the nuclear spin echo signals produced as a rule by.