title: Safety of MR imaging in patients who have retained metallic materials after cardiac surgery.
abstract: OBJECTIVE
  Epicardial pacing wires retained in patients who undergo cardiac surgery are thought to be a relative contraindication to MR imaging. However, to our knowledge no published evidence supports this belief. Because other metallic materials retained after cardiac surgery might represent a hazard to patients who undergo MR imaging, we sought to determine the safety of such imaging.
  
  
  METHODS
  We examined 200 patients who underwent MR imaging at 1 or 1.5 T after cardiac surgery. Eighty-one were examined with ECG monitoring. The presence of temporary epicardial pacing wires, prosthetic valves, and other metal materials was confirmed by chest radiography.
  
  
  RESULTS
  Of the 200 patients reviewed, all had postoperative metallic material visible on chest radiographs. Temporary epicardial pacing wire, cut short at the skin, was seen in 51 patients. Of the 81 patients examined with ECG monitoring, we found that MR imaging produced no changes from baseline ECG rhythms. None of the 200 patients reported symptoms suggesting arrhythmia or other cardiac dysfunction during MR imaging.
  
  
  CONCLUSIONS
  MR imaging can be performed safely in patients who have undergone cardiac surgery and have retained metallic material, including valve replacements and temporary epicardial pacing wires cut short at the skin. MR imaging of patients with pacemakers was not evaluated, and we recommend that pacemakers remain a contraindication to MR imaging.
authors.affiliation: Department of Radiological Sciences, Deaconess Hospital, Boston, MA, USA.
authors.forename: G G
authors.initials: GG
authors.lastname: Hartnell
authors.forename: L
authors.initials: L
authors.lastname: Spence
authors.forename: L A
authors.initials: LA
authors.lastname: Hughes
authors.forename: M C
authors.initials: MC
authors.lastname: Cohen
authors.forename: R
authors.initials: R
authors.lastname: Saouaf
authors.forename: B
authors.initials: B
authors.lastname: Buff
mesh_terms: D006348:Cardiac Surgical Procedures; D000075202:Contraindications; D004562:Electrocardiography; D004567:Electrodes, Implanted; D006350:Heart Valve Prosthesis; D006801:Humans; D008279:Magnetic Resonance Imaging; D008670:Metals; D011183:Postoperative Complications / Q000175:diagnosis / Q000000981:diagnostic imaging; D011859:Radiography; D012449:Safety
chemical_list: D008670:Metals