Significant Artifact Reduction at 1.5T and 3T MRI by the Use of a Cochlear Implant with Removable Magnet: An Experimental Human Cadaver Study

Franca Wagner; Wilhelm Wimmer; Lars Leidolt; Mattheus Vischer; Stefan Weder; Roland Wiest; Georgios Mantokoudis; Marco D Caversaccio

doi:10.1371/journal.pone.0132483

Significant Artifact Reduction at 1.5T and 3T MRI by the Use of a Cochlear Implant with Removable Magnet: An Experimental Human Cadaver Study

PLoS One. 2015 Jul 22;10(7):e0132483. doi: 10.1371/journal.pone.0132483. eCollection 2015.

Authors

Franca Wagner¹, Wilhelm Wimmer², Lars Leidolt¹, Mattheus Vischer³, Stefan Weder³, Roland Wiest¹, Georgios Mantokoudis³, Marco D Caversaccio²

Affiliations

¹ University Department of Diagnostic and Interventional Neuroradiology, Inselspital Bern, Bern, Switzerland.
² University Department of Otorhinolaryngology, Head & Neck Surgery, Inselspital Bern, Bern, Switzerland; ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland.
³ University Department of Otorhinolaryngology, Head & Neck Surgery, Inselspital Bern, Bern, Switzerland.

Abstract

Objective: Cochlear implants (CIs) are standard treatment for postlingually deafened individuals and prelingually deafened children. This human cadaver study evaluated diagnostic usefulness, image quality and artifacts in 1.5T and 3T magnetic resonance (MR) brain scans after CI with a removable magnet.

Methods: Three criteria (diagnostic usefulness, image quality, artifacts) were assessed at 1.5T and 3T in five cadaver heads with CI. The brain magnetic resonance scans were performed with and without the magnet in situ. The criteria were analyzed by two blinded neuroradiologists, with focus on image distortion and limitation of the diagnostic value of the acquired MR images.

Results: MR images with the magnet in situ were all compromised by artifacts caused by the CI. After removal of the magnet, MR scans showed an unequivocal artifact reduction with significant improvement of the image quality and diagnostic usefulness, both at 1.5T and 3T. Visibility of the brain stem, cerebellopontine angle, and parieto-occipital lobe ipsilateral to the CI increased significantly after magnet removal.

Conclusions: The results indicate the possible advantages for 1.5T and 3T MR scanning of the brain in CI carriers with removable magnets. Our findings support use of CIs with removable magnets, especially in patients with chronic intracranial pathologies.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Artifacts
Brain / diagnostic imaging*
Cadaver
Cochlear Implantation / adverse effects
Cochlear Implantation / instrumentation*
Device Removal / adverse effects*
Humans
Magnetic Resonance Imaging / methods
Magnets
Radiographic Image Interpretation, Computer-Assisted / methods*

Grants and funding

The authors of this manuscript declare that they thank the MEDEL Corporation [MED-EL Corporation, Innsbruck, Austria] for loan of the cochlear implants and funding that study [total amount 15 000€]. The authors state that this work has received funding from MED-EL Corporation [MED-EL Corporation, Innsbruck, Austria] in the amount of 15 000€. Additionally, the authors confirm that the funders had no role in our study design, data collection and analysis, decision to publish, or preparation of the manuscript.