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Prosthetic heart valves: Evaluation of magnetic field interactions, heating, and artifacts at 1.5 T
Author(s) -
Edwards MariaBenedicta,
Taylor Kenneth M.,
Shellock Frank G.
Publication year - 2000
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 - 10.1002/1522-2586(200008)12:2<363::aid-jmri21>3.0.co;2-3
Subject(s) - imaging phantom , magnetic resonance imaging , heart valve , magnetostatics , specific absorption rate , biomedical engineering , magnetic field , materials science , spin valve , nuclear magnetic resonance , nuclear medicine , computer science , medicine , radiology , physics , surgery , magnetization , telecommunications , quantum mechanics , antenna (radio)
The purpose of this study was to use ex vivo testing techniques to determine the magnetic resonance imaging (MRI) safety aspects for 32 different heart valve prostheses that had not been evaluated previously in association with the 1.5‐T MR environment. Ex vivo testing was performed using previously described techniques for the evaluation of magnetic field interactions (deflection angle and torque), heating [gel‐filled phantom and fluoroptic thermometry; 15 minutes of MRI at a specific absorption rate (SAR) of 1.1 W/kg], and artifacts (using gradient echo and T1‐weighted spin‐echo pulse sequences). Thirteen heart valve prostheses displayed interactions with the magnetic field. However, these magnetic field interactions were considered relatively minor. Heating was ≤0.8°C for these implants. Artifacts varied from mild to severe depending on the amount and type of metal used to make the particular heart valve prosthesis. For these 32 different heart valve prostheses, the relative lack of substantial magnetic field interactions and negligible heating indicate that MR procedures may be conducted safely in individuals with these implants using MR systems with static magnetic fields of 1.5 T or less. J. Magn. Reson. Imaging 2000;12:363–369. © 2000 Wiley‐Liss, Inc.