Parametric Assessment of the Effect of Cochlear Implant Positioning on Brain MRI Artefacts at 3 T

Autor: Kitterick, Padraig, Dewey, Rebecca, Dineen, Robert, Clemence, Matthew, Dick, Olivier, Bowtell, Richard
Jazyk: angličtina
Rok vydání: 2021
ISSN: 1531-7129
1537-4505
Popis: Background: Brain magnetic resonance imaging (MRI) in patients with cochlear implants (CIs) is impacted by image artefacts.Hypothesis: The optimal positioning of the CI to minimise artefacts is unknown. This study aimed to characterise the dependence of the extent and distribution of the artefact on CI positioning.Methods: Three normally-hearing individuals underwent MRI using a standard T1-weighted 3D sequence. Scans were acquired with a non-functioning CI placed underneath a swimming cap at four plausible scalp positions on each side, and without the CI in situ. The artefact in each image was assessed quantitatively using voxel-based techniques. Two radiologists also independently rated the likely impact of the artefact on detection of pathology for 20 neuroradiological locations.Results: The procedure was well tolerated. The most postero-inferior CI positions resulted in the smallest apparent artefacts. Radiological evaluations suggested that artefacts would likely limit pathology detection in the ipsilateral temporal, parietal and occipital lobes, regardless of CI location. Pathology detection in contralateral structures and anterior corpus callosum was rarely affected. Certain CI locations appeared to selectively spare ipsilateral structures, e.g., postero-inferior CI locations selectively spared ipsilateral midbrain, deep grey matter, and frontal lobes.Conclusion: A CI placed under a swimming cap is a feasible tool for observing the effect of CI location on image usability within a single subject and potentially informing surgical planning. Regardless of CI placement, artefacts involving ipsilateral parietal, temporal and occipital lobes severely limited diagnostic image utility. Between 35% and 70% of neuroradiological features were deemed unaffected by the implant.
Databáze: OpenAIRE
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