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59. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC)
3. Joint Meeting mit der Italienischen Gesellschaft für Neurochirurgie (SINch)

Deutsche Gesellschaft für Neurochirurgie (DGNC) e. V.

01. - 04.06.2008, Würzburg

MRI visualisation of crucial infra- and supratentorial structures after placement of magnetic auditory brainstem implant: a retrospective study

MR-Bildgebung infra- und supratentorieller Strukturen bei implantiertem auditorischen Hirnstammimplantat

Meeting Abstract

  • corresponding author J. Coburger - Neurochirurgische Klinik und Poliklinik, Universitätsklinikum Würzburg
  • E. Kigadye - Neurochirurgische Klinik und Poliklinik, Universitätsklinikum Würzburg
  • C. Knaus - Klinik für HNO-Heilkunde, Universitätsklinikum Würzburg
  • A. Bartsch - Abteilung Neuroradiologie, Universitätsklinikum Würzburg
  • K. Roosen - Neurochirurgische Klinik und Poliklinik, Universitätsklinikum Würzburg
  • C. Matthies - Neurochirurgische Klinik und Poliklinik, Universitätsklinikum Würzburg

Deutsche Gesellschaft für Neurochirurgie. Società Italiana di Neurochirurgia. 59. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), 3. Joint Meeting mit der Italienischen Gesellschaft für Neurochirurgie (SINch). Würzburg, 01.-04.06.2008. Düsseldorf: German Medical Science GMS Publishing House; 2008. DocP 023

Die elektronische Version dieses Artikels ist vollständig und ist verfügbar unter: http://www.egms.de/de/meetings/dgnc2008/08dgnc291.shtml

Veröffentlicht: 30. Mai 2008

© 2008 Coburger et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielf&aauml;ltigt, verbreitet und &oauml;ffentlich zug&aauml;nglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

Objective: Auditory brainstem implants (ABI) bring about a significant improvement of quality of life in Neurofibromatosis Type 2 (NF2) patients. In view of likely further disease progression with multiple intracranial tumours, regular radiological follow-up is essential. Principles on safe MRI performance in ABI implanted patients were established and shown to be safe in magnet-free as well as in special magnet containing ABI. However, an immense image distortion might impair assessment. Aim of the study was to evaluate MRI visualisation of crucial structures of the cerebello-pontine angle (CPA), brainstem and hemispheres as well as the feasibility of tumour follow-up after placement of ABI with magnetic coil.

Methods: In a consecutive series of 12 patients with ABI implanted between 2005 and 2007 pre- and postoperative MRI were compared. For evaluation axial slices at the level of the internal auditory canal, the 3rd ventricle and the apical cortex were evaluated for visualisation of anatomical structures and of existing preoperative pathologies. The possible visualisation was graded from 0 to 4, with grade 0 showing no image distortion, grade 1 slight distortion, grade 2 moderate and grade 3 advanced distortion, but contained tumour borders, and grade 4 making an assessment of the region impossible.

Results: MRI could be obtained in implanted patients without any side effects, especially no neurological disturbance and no dysfunction of the ABI device. Regarding delineation of anatomical structures, the brainstem, the ventricle and the parietal lobe were slightly distorted on the ipsilateral side (grades 1 to 2), with no impairment on the contralateral side (grade 0). The ipsilateral CPA and temporal lobe showed a medium distortion (grades 2) whereas the contralateral regions again were without any impairment of visualisation. For tumour follow-up, 1 out of 15 tumors to be observed, was not visible (grade 4) (7%).

Conclusions: Image quality for ipsilateral infratentorial structures was impaired in ABI patients. The deterioration implied some distortion, but visibility was contained. Except for the ipsilateral cpa, all the other anatomical regions were well exposed and evaluable for tumor growth and recurrence. In order to obtain detailed information on the ipsilateral CPA, an extraction of the magnet or a contrast enhanced computertomography may be necessary.