Magnetic Resonance Imaging Compatibility of a New Generation of Active Middle Ear Implant: A Clinically Relevant Temporal Bone Laboratory Study.

Objective: Magnetic resonance imaging (MRI) has become an essential tool of modern medical imaging and disease diagnosis. In November 2014, a new MRI-conditional (up to 1.5 T) generation of an active middle ear implant (AMEI) was released to the market.The aim of the study was to test the MRI compatibility of the new implant system in a clinical-anatomical study.

Design: Experimental cadaver head model.

Setting: Temporal bone laboratory.

Participants: AMEIs were implanted in 28 fixed temporal bones at three different floating mass transducer (FMT)-coupling positions (N = 8 short process of the incus, N = 16 long process of the incus, N = 4 round window).

Main Outcome Measures: The position of the FMT and the integrity of the ossicular chain was monitored through microscopy, microendoscopy, and computed tomography (CT) scans before and after the MRI (1.5 T) was conducted. Proper function of the implant was tested with reverse transfer function (RTF) measurements.

Results: Neither positional nor functional changes after MRI were observed.

Conclusion: The new generation of the AMEI is a MRI-compatible system, which features an easier and quicker implant fixation method. The option of MRI in patients with AMEI should be taken into consideration during the preoperative discussion with potential candidates.