title: Yasargil aneurysm clips: evaluation of interactions with a 1.5-T MR system.
abstract: OBJECTIVE
  To evaluate the magnetic field interactions with Yasargil aneurysm clips exposed to a 1.5-T MR system.
  
  
  METHODS
  Sixteen Yasargil aneurysm clips made with Phynox (10 clips returned to the manufacturer due to suspected magnetic field interactions and six clips obtained from the manufacturer in sterile packages) were tested for magnetic field interaction at 1.5 T by using techniques to assess magnetic field-induced translational (deflection angle test) and torque (changes in alignment or rotation) forces.
  
  
  RESULTS
  None of the aneurysm clips demonstrated magnetic field interactions; that is, deflection angles were zero and there were no changes in alignment or evidence of rotational forces present.
  
  
  CONCLUSIONS
  It is safe to perform MR procedures at 1.5 T or less in patients with Yasargil aneurysm clips made with nonferromagnetic material.
authors.affiliation: Department of Radiology, University of Southern California, School of Medicine, Los Angeles, USA.
authors.forename: F G
authors.initials: FG
authors.lastname: Shellock
authors.forename: E
authors.initials: E
authors.lastname: Kanal
mesh_terms: D000497:Alloys; D016477:Artifacts; D001921:Brain; D002858:Chromium Alloys; D003035:Cobalt; D000075202:Contraindications; D005290:Ferric Compounds / Q000009:adverse effects; D005547:Foreign Bodies / Q000175:diagnosis*; D006801:Humans; D066298:In Vitro Techniques; D002532:Intracranial Aneurysm / Q000175:diagnosis* / Q000601:surgery; D018810:Magnetic Resonance Angiography / Q000295:instrumentation* / Q000379:methods; D013525:Surgical Instruments / Q000009:adverse effects / Q000706:statistics & numerical data
chemical_list: D000497:Alloys; D002858:Chromium Alloys; D005290:Ferric Compounds; C112499:phynox; C001215:ferrite; D003035:Cobalt