Artikel
MRI imaging with implanted auditory brain stem implant in NF-2 patients
MRT-Bildgebung bei NF-2 Patienten mit implantiertem auditorischen Hirnstamm-Implantat
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Veröffentlicht: | 30. Mai 2008 |
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Gliederung
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Objective: To investigate the feasibility of MRI in patients suffering from Neurofibromatosis after beeing implanted with an auditory brainstem implant (ABI) for hearing restoration. MRI is important for follow-up of brain and spinal tumors especially in these patients. Electronic circuits and implanted magnets of the ABI may inhibit sufficient imaging or need an operative removal of the magnet before scanning.
Methods: Prior in vitro studies with the implant used showed that no adverse effects on electronics, no currents at the stimulating electrode and no heating occurred using 0.2 or 1.5 Tesla devices. The mechanical forces to the magnet were low. In total five patients were investigated ten times using a 1.5 Tesla MRI machine. Spin echo and FFE sequencies were performed. The patient must be positioned correctly in the MRI scanner. The implantation must date back 3-6 months, a special company approval is mandatory.
Results: Investigations were performed in 2 patients 3 times, in one patient 2 times and in 2 patients once. The patients reported no adverse effects or sensations. No damage to the electronics or demagnetization happened. The implant was stable in position and was used as before by the patients just after the examination. The obtained images were of very good quality but for the implanted area.
Conclusions: In a slowly progressive disease repetitive imaging is very important. Especially in NF-2 patients who are implanted with an ABI, MRI scans may be impossible, dangerous or only possible after removing the magnet. With the examined device a safe and repetitive MRI imaging is possible without additional operation for magnet removal.