MRI Observation After Intralabyrinthine and Vestibular Schwannoma Resection and Cochlear Implantation

Abstract

Objective: MRI observation is part of the regular follow-up after vestibular schwannoma (VS) or intralabyrinthine schwannoma (ILS) resection. Because cochlear implantation (CI) after resection is part of the audiological rehabilitation process, the magnet resonance imaging (MRI) behavior of CI systems needs to be considered. In light of recent developments in MRI artifact positioning and pain prevention, this study evaluates reproducible MRI observations after tumor resection and CI surgery as part of follow-up. Methods: In a retrospective study, we evaluated 9 patients with a T1 KM, T2 sequence MRI observation, and cone beam computed tomography (CBCT) after ILS/VS resection and CI. In all but one case, a CI with a diametrically bipolar magnet and a receiver positioned 8-9 cm behind the external auditory canal was performed. Results: In all but one case, MRI observation allowed for a pain-free visual assessment of the intralabyrinthine and internal auditory canal (IAC) regions. In one case, a painful dislodgement of the receiver magnet occurred. Conclusion: MRI follow-up after ILS and VS resection and CI is reproducibly possible. Implant choice and positioning should be considered before implantation to allow for a pain-free visual assessment afterward. This finding allows for the first time a widening of the indication into this patient group.

Ipsilateral Vestibular Schwannoma after Cochlear Implantation

“…is finding underlines the importance of performing MRI scans even in cases of asymmetric hearing loss. e new developments in cochlear implant magnets, implant position, and head position inside the scanner make the follow-up possible, even for cochlear implantees [5].…”

“…e development of cochlear implant magnets and increasing knowledge of implant and head position make it possible to perform MRI after cochlear implantation for postoperative visual assessment of the cochlea and internal auditory canal. For example, an evaluation of vestibular schwannoma and intralabyrinthine schwannoma after cochlear implantation was shown to be successful [5].…”

The role of cochlear implant positioning on MR imaging quality: a preclinical in vivo study with a novel implant magnet system

“…The increasing number of patients undergoing CI surgery, related to an evident expansion of selection criteria [11][12][13][14] and an impressive evolution of health care technology [15,16], has raised many concerns about the issue of CI-MRI compatibility [17,18]. How best to manage the MRI artifact represents one of the emerging topics related to the new generation of CIs.…”

Quality Control after Intracochlear Intralabyrinthine Schwannoma Resection and Cochlear Implantation

“…Walton et al, [ 23 ] were the first to perform a schwannoma follow-up after cochlear implantation in NF II cases. The ability to reproducibly evaluate vestibular schwannomas and ILSs after removal and cochlear implantation has recently been shown [ 12 ]. Evaluation of the IAC and cochlea after cochlear implantation is based on proper implant and patient position [ 18 , 23 , 24 , 25 ]; magnet development, which allows for pain-free observation [ 26 ]; and the choice of the right MRI sequence [ 27 ].…”

“…Long-term control of the surgical success of the tumor removal and a follow-up have so far not been possible. The new developments in cochlear implant magnet development, implant position, and head position inside the scanner make postoperative magnetic resonance imaging (MRI) follow-up of this tumor class possible [ 12 ]. Second generation magnet (e.g., diametral bipolar), positioning of the receiver implant magnet more than 8 cm from the external auditory canal, low artifact generating sequences (e.g., T2 TSE, non 3D), and a chin-to-chest position of the head inside the scanner are the key factors.…”