This chapter deals with the problems that can occur during X-ray, CT, and MRI examinations due to metallic components of medical foreign bodies. The most relevant problems in this regard are motion artifacts, metal artifacts (extinction artifacts, hardening artifacts), technical disturbances (device damage and malfunctions in the MRI, damage to implants), induction of electrical currents, heat development, interaction between ferromagnetic materials and the magnetic field. Furthermore, the procedure for implant carriers in connection with MRI examinations is discussed.