ABSTRACTA selection of commonly used metal ossicular prostheses were tested to see if they were attracted by the 5000-gauss magnetic field of a magnetic resonance imager. None of the prostheses tested was attracted by the magnetic field. Using a model system, it was found that some of the metal objects perturbed the magnetic field, thus affecting the image produced by the scanner. Therefore, while metal implants may be safe in a powerful magnetic field, they can alter the field, resulting in abnormal images.