Document Detail


Prosthetic heart valves and annuloplasty rings: assessment of magnetic field interactions, heating, and artifacts at 1.5 Tesla.
MedLine Citation:
PMID:  11777223     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The purpose of this study was to determine the magnetic resonance (MR) safety aspects and artifacts for three different heart valve prostheses and two different annuloplasty rings that have 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 min of MR imaging at a whole body-averaged specific absorption rate of 1.2 W/kg), and artifacts (using T1-weighted, spin echo, and gradient echo pulse sequences). One heart valve prosthesis and one annuloplasty ring showed no magnetic field interactions. Two heart valve prostheses and one annuloplasty ring displayed relatively minor magnetic field interactions (i.e., deflection angle < or = 6 degrees, torque, +1). Heating was < or = 0.7 degrees C for the five different implants. Artifacts varied depending on the amount and type of metal used to make the implants. For the three heart valve prostheses and two annuloplasty rings, the lack of substantial magnetic field interactions and relatively minor hearing indicated that MR procedures may be conducted safetly in patients with these implants using MR systems operating with static magneticfields of 1.5 T or less. Notably, these findings essentially apply to 54 different heart valve prostheses and 37 different annuloplasty rings (i.e., based on the various models and sizes available for these implants).
Authors:
F G Shellock
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of cardiovascular magnetic resonance : official journal of the Society for Cardiovascular Magnetic Resonance     Volume:  3     ISSN:  1097-6647     ISO Abbreviation:  J Cardiovasc Magn Reson     Publication Date:  2001  
Date Detail:
Created Date:  2002-01-04     Completed Date:  2002-04-10     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  9815616     Medline TA:  J Cardiovasc Magn Reson     Country:  United States    
Other Details:
Languages:  eng     Pagination:  317-24     Citation Subset:  IM    
Affiliation:
University of South California, School of Medicine, Los Angeles, USA.
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MeSH Terms
Descriptor/Qualifier:
Artifacts
Electromagnetic Fields / adverse effects
Heart Valve Prosthesis*
Hot Temperature
Humans
Magnetic Resonance Imaging / adverse effects*
Prosthesis Failure
Torque

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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