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A novel method for measuring the torque on implantable cardiovascular devices in MR static fields
Author(s) -
D'Avenio Giuseppe,
Canese Rossella,
Podo Franca,
Grigioni Mauro
Publication year - 2007
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.21146
Subject(s) - torque , scanner , deflection angle , magnetic field , biomedical engineering , torsion spring , deflection (physics) , torsion (gastropod) , electromagnetic coil , materials science , physics , optics , surgery , medicine , classical mechanics , quantum mechanics , thermodynamics
Purpose To propose a novel quantitative method for measuring the torque acting on mechanical heart valve prostheses subjected to a high static magnetic field in a MR scanner. Materials and Methods Torque measurements were performed with a torsion balance, implemented with a copper wire. The reaction torque exerted by the static magnetic field on the device was measured optically from the deflection angle of a laser beam spot on a graduate scale. Three different types of mechanical valves (two bileaflet and one monoleaflet) were tested at different locations of a small bore 4.7 tesla system. Results The method proved to be particularly sensitive (detectability limit lower than 10 −6 N · m), reliable and yielded quantitative reproducible results. The equivalent force of the torque measured for the three valves was at least 10 3 ‐fold lower than the force exerted by the beating heart. Conclusion The proposed method provides a quantitative evaluation of the torque induced on prosthetic device by a MR scanner operating at high magnetic field. J. Magn. Reson. Imaging 2007;26:1368–1374. © 2007 Wiley‐Liss, Inc.