Magnetic ports in tissue expanders--a caution for MRI.

Although a great deal is known about the potential hazards of ferromagnetic materials relative to MRI, little has been written about the safety of tissue panders. Recently a new modification of the existing ports has been made available by incorporating a magnet for ease of identification of the injection site. Despite its low mass, the intrinsic magnetic field presents a contra-indicating factor due to the potential for torque and movement in the presence of the strong magnetic field found in the clinical MR imagers. With any evidence of tissue expander prosthesis obtained in the history, a careful questioning about the possibility of a magnetic port should be carried out.