Aneurysm Clip Motion during Magnetic Resonance Imaging: In Vivo Experimental Study with Metallurgical Factor Analysis

摘要: Because of various mechanical, metallurgical, and commercial constraints, aneurysm clips are manufactured from different alloys, including several stainless steel cobalt alloys. Some the steels contain volume fractions crystal phase known as martensite. Martensitic alloys have body-centered cubic structure, prone to stress corrosion failure, ferromagnetic. can be displaced like a compass needle when exposed magnetic field such that generated during resonance imaging (MRI). The force exerted by is proportional fraction phase. We investigated martensitic content field-induced displacement 12 common clips. Four each following types were examined: Sugita, Sundt-Kees Multi-Angle, Heifetz (two types), Vari-Angle McFadden, Yasargil Scoville, Mayfield, Vari-Angle, Pivot, Kapp. Phase homogeneity structure analyzed x-ray diffraction using Phillips diffractometer. Clip deflection in an Oxford Research Systems MRI spectrometer was measured our vivo rat abdominal aortic model. Results showed correlated with magnitude deflection. Among examined, Yasargil, Elgiloy, McFadden had nonmartensitic composition did not deflect field. Scoville contained 5% martensite deflected only marginally. Martensite comprised 35% Mayfield clip, which 45 degrees, 90% Heifetz, Multi-Angle clips, approximately 70 degrees or slipped off aneurysm.(ABSTRACT TRUNCATED AT 250 WORDS)