Evaluation of 39 medical implants at 7.0 T

Br J Radiol. 2015;88(1056):20150633. doi: 10.1259/bjr.20150633. Epub 2015 Oct 20.

Abstract

Objective: With increased signal to noise ratios, 7.0-T MRI has the potential to contribute unique information regarding anatomy and pathophysiology of a disease. However, concerns for the safety of subjects with metallic medical implants have hindered advancement in this field. The purpose of the present research was to evaluate the MRI safety for 39 commonly used medical implants at 7.0 T.

Methods: Selected metallic implants were tested for magnetic field interactions, radiofrequency-induced heating and artefacts using standardized testing techniques.

Results: 5 of the 39 implants tested may be unsafe for subjects undergoing MRI at 7.0 T.

Conclusion: Implants were deemed either "MR Conditional" or "MR Unsafe" for the 7.0-T MRI environment. Further research is needed to expand the existing database categorizing implants that are acceptable for patients referred for MRI examinations at 7.0 T.

Advances in knowledge: Lack of MRI testing for common metallic medical implants limits the translational potential of 7.0-T MRI. For safety reasons, patients with metallic implants are not allowed to undergo a 7.0-T MRI scan, precluding part of the population that can benefit from the detailed resolution of ultra-high-field MRIs. This investigation provides necessary MRI testing of common medical implants at 7.0 T.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Artifacts
  • Equipment Safety
  • Magnetic Resonance Imaging / instrumentation*
  • Magnetic Resonance Imaging / methods*
  • Magnetics
  • Metals*
  • Prostheses and Implants / statistics & numerical data*
  • Risk Assessment

Substances

  • Metals