Magnet dislocation following magnetic resonance imaging in cochlear implant users: Diagnostic pathways and managment

Holtmann, L; Hans, Stefan; Kaster, F; Müller, Verena; Lang, Stephan; Göricke, Sophia; Lang‐Roth, Ruth; Arweiler‐Harbeck, Diana

doi:10.1080/14670100.2021.1872906

Cited by 8 publications

(9 citation statements)

References 22 publications

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“…Some sites have routinely performed a Stenvers view radiograph after MRI examination to rule out a magnet dislocation [ 17 – 19 ]. Such a procedure was not implemented here because magnet dysfunction or displacements were routinely checked in the ENT department—also sparing the patient from ionizing radiation.…”

Section: Discussionmentioning

confidence: 99%

Complications of cochlear implants with MRI scans in different body regions: type, frequency and impact

et al. 2023

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Objectives The aim was to assess the type, frequency and impact of MRI-related complications in patients with cochlear implants (CI) and MRI indications in different body regions. Methods For that purpose, the institutional radiology database of a single tertiary hospital was searched for patients with a CI who underwent MRI between 2001 and 2018. The number of MRI examinations and complications were retrieved from the patient record. Examinations were categorized into five distinct body regions or combinations thereof. Records of CI artifacts in the head also included basic information on diagnostic image quality. Results Out of 1017 MRI database entries (examinations) of patients with a CI, 91 records were after implantation (71 patients) and 66 were attempted (no contraindications, 49 patients). In four cases (4/66, 6.1%), the magnet was dislocated and had to be replaced surgically. Three out of four severe complications occurred for examination regions outside the head. Thirteen MRI examinations were aborted due to pain (19.7%) and one because of artifacts—resulting in 48 scans (72.7%) completed successfully (36 patients). All cranial scans featured device artifacts in all sequences, but the majority of them did not affect proper imaging diagnostics in the respective region. Conclusion This retrospective, single-center analysis of patients with MRI-conditional cochlear implants shows that MRI-related complications were common, at least in models with a fixed magnet, despite appropriate precautions and compliance with the manufacturers’ guidelines. MRI examinations of CI patients should therefore be indicated strictly until the exact causes have been clarified.

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Section: Discussionmentioning

confidence: 99%

Complications of cochlear implants with MRI scans in different body regions: type, frequency and impact

et al. 2023

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“…They state that minimal literature is currently available on the imaging of magnet dislocation. Holtmann et al [14] found that by diagnosing magnet dislocation using CT, prompt diagnosis was delayed in some cases because of artefacts. Nevertheless, CT has proved its worth in rare but serious CI complications, such as subdural and epidural haematoma [23][24][25].…”

Section: Discussionmentioning

confidence: 99%

“…Although many studies have focused on the surgical and medical complications that occur after cochlear implantation [4][5][6]10], data on imaging methods for the optimal diagnostic workup of these complications is limited and inconclusive. Mostly, temporal bone computed tomography (CT) or X-ray examination is recommended when dealing with cochlear implant (CI) complications [7,8,[11][12][13][14]. In this context, 82.4% of CT scans showed no abnormalities in CI complications but exposed the patients to radiation [15].…”

Section: Introductionmentioning

confidence: 99%

Diagnosing complications following cochlear implantation using transcutaneous ultrasound

Rupp

Thimsen

Balk

et al. 2021

Eur Arch Otorhinolaryngol

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Purpose The aim of this study was to investigate the feasibility and reliability of transcutaneous ultrasound for the detection of complications after cochlear implantation. Methods In a single center retrospective cohort study, 115 consecutive cases of suspected complications after cochlear implantation (intervention group) were examined. The rate of pathologic ultrasound findings for specific leading symptoms and diagnoses was compared to a control group comprising twenty consecutive cochlear implants in symptom-free patients. Results Diagnostic ultrasound showed distinctly more pathologic findings in the intervention group (n = 67; 58.3%; p < 0.001) compared to the control group (n = 1; 5%). Ultrasound revealed significantly more pathologic findings in haematoma or seroma around the implant (n = 17; 100%; p < 0.001; ϕ = 0.94) and magnet dislocation (n = 44; 97.7%; p < 0.001; ϕ = 0.92) confirmed by a strong effect. Ultrasound examination showed a medium to high effect size in patients presenting with local infections (n = 3; 21.4%; p = 0.283; ϕ = 0.25) and skin flap oedema (n = 2; 50%; p = 0.061; ϕ = 0.51). In contrast, ultrasound examinations displayed a low effect size in undefined cephalgia (0%; p = 0.444; ϕ = 0.17) and device malfunction or failure (0%; p > 0.999; ϕ = 0.13). Conclusion Transcutaneous ultrasound can be advocated as a feasible and effective method in the diagnostic work-up of magnet dislocation and haematoma or seroma around the implant following cochlear implantation. Contrary, ultrasound findings can be expected to be inconspicuous in patients presenting with undefined cephalgia and device malfunction or failure.

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“…Moreover, it is oftentimes the case that prior medical procedures or implantations prevent individuals from procedures such as magnetic resonance imaging. For hearing research specifically, cochlear implants frequently fall under the latter category (Leinung et al, 2020 ; Holtmann et al, 2021 ). In either case, a better understanding of the effects of the individualization steps may help the planning and uncertainty assessment of EEG studies.…”

Section: Introductionmentioning

confidence: 99%

Effects of individualized brain anatomies and EEG electrode positions on inferred activity of the primary auditory cortex

Ignatiadis

Barumerli

Tóth

et al. 2022

Front. Neuroinform.

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Due to its high temporal resolution and non-invasive nature, electroencephalography (EEG) is considered a method of great value for the field of auditory cognitive neuroscience. In performing source space analyses, localization accuracy poses a bottleneck, which precise forward models based on individualized attributes such as subject anatomy or electrode locations aim to overcome. Yet acquiring anatomical images or localizing EEG electrodes requires significant additional funds and processing time, making it an oftentimes inaccessible asset. Neuroscientific software offers template solutions, on which analyses can be based. For localizing the source of auditory evoked responses, we here compared the results of employing such template anatomies and electrode positions versus the subject-specific ones, as well as combinations of the two. All considered cases represented approaches commonly used in electrophysiological studies. We considered differences between two commonly used inverse solutions (dSPM, sLORETA) and targeted the primary auditory cortex; a notoriously small cortical region that is located within the lateral sulcus, thus particularly prone to errors in localization. Through systematical comparison of early evoked component metrics and spatial leakage, we assessed how the individualization steps impacted the analyses outcomes. Both electrode locations as well as subject anatomies were found to have an effect, which though varied based on the configuration considered. When comparing the inverse solutions, we moreover found that dSPM more consistently benefited from individualization of subject morphologies compared to sLORETA, suggesting it to be the better choice for auditory cortex localization.

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Magnet dislocation following magnetic resonance imaging in cochlear implant users: Diagnostic pathways and managment

Cited by 8 publications

References 22 publications

Complications of cochlear implants with MRI scans in different body regions: type, frequency and impact

Complications of cochlear implants with MRI scans in different body regions: type, frequency and impact

Diagnosing complications following cochlear implantation using transcutaneous ultrasound

Effects of individualized brain anatomies and EEG electrode positions on inferred activity of the primary auditory cortex

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