Patients should not have metal objects on them during an MRI. Normally, before an MRI, the doctor will ask the patient not to have metal objects with them. This is because the strong magnetic force generated by the MRI during the MRI will cause the metal objects to shift and may cause accidental injury to the person’s body. In addition, metal objects outside the body may be drawn into the machine by the magnetic field and destroy the machine. There are also some patients who have metal devices implanted in their bodies for treatment that can be displaced or dislodged by a strong magnetic field and cause harm to the patient.