Effect of head position on cochlear implant MRI artifact
- PDF / 952,057 Bytes
- 5 Pages / 595.276 x 790.866 pts Page_size
- 49 Downloads / 217 Views
OTOLOGY
Effect of head position on cochlear implant MRI artifact N. Ay2 · H. B. Gehl1 · H. Sudhoff2 · I. Todt2 Received: 7 June 2020 / Accepted: 31 August 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract Purpose A new generation of cochlear implant (CI) magnets and specific surgical techniques (e.g., implant positioning) has changed the relationship between a CI and magnet resonance imaging (MRI). MRI allows a pain free in vivo evaluation of the inner ear fluid state and internal auditory canal after the insertion of an electrode. The aim of this study is to evaluate how the patient’s head position in the MRI scanner influences the CI magnet-related artefact. Methods We performed in vivo measurement of MRI artefacts at 3 T with a CI system containing a bipolar diametrical magnet. The implant magnet was positioned with a head bandage at different positions from the nasion and external auditory canal in three volunteers. We used a turbo spin echo (TSE) T2w sequence on the axial and coronal planes and observed three positions: (1) regular position, (2) chin to chest (anteflexion), and (3) hyperextension (retroflexion). Results By comparing the positions, anteflexion of the cervical spine in a chin-to-chest position allowed us to place the artefact in a more apical position from the IAC in the coronal plane. The hyperextension of the cervical spine position shifts the artefact father towards the cochlea’s direction. Conclusion The head’s position can influence the location of MRI artefacts. In cases where the artefact diminished the IAC or cochlea, anteflexion of the cervical spine in the chin-to-chest position of the head in the MRI scanner should be attempted to allow a visualization of the IAC. Keywords MRI artefact · Cochlear implant · Head position · Complication · Internal auditory canal
Introduction Magnet resonance imaging (MRI) scanning in cochlear implantees have been a contraindication for a long time [1]. The use of headbands allowed MRI scans to be possible to some degree possible. However, the risk of magnet dislocation and pain has persisted. The first generation of internal magnets was associated with complications such as pain or dislodged magnets [2–4] at 1.5 T. An approval for 3 T scans was given with a magnet removal at 3 T (e.g., Series 5 implant, Cochlear Company, Sydney, Australia; Neuro 2, Oticon, Valauris, France).
* I. Todt [email protected] 1
Department of Radiology, Klinikum Bielefeld, Bielefeld, Germany
Department of Otolaryngology, Head and Neck Surgery, Klinikum Bielefeld, Teutoburgerstr. 50, 33604 Bielefeld, Germany
2
An internal magnet generation containing diametrically bipolar magnets (e.g., Synchrony, Medel, Austria, Innsbruck; 3D Implant, Advanced Bionics, Stäfa, Swiss; 6 er series, Cochlear, Melbourne, Australia) made pain-free MRI scans at 3 T possible, even without a headband [5]. MRI-based visualization of the cochlea and the internal auditory canal, after an implantation is performed [6], can be useful, and such an evaluation is influenc
Data Loading...
