MRI evaluation of the Osia® 2 hearing implant with OSI300 actuator: insights from a full-head cadaver model.

OBJECTIVES

Our study aimed to evaluate the impact of magnetic resonance (MR) image artefacts caused by the OSI300 implant system on the ability to visualize specific cranial structures.

METHODS

One cadaveric head was unilaterally implanted and underwent MR imaging in 1.5 and 3 Tesla magnetic fields under the following conditions: (1) no device, (2) Cochlear BI300 plus OSI300 with magnet, (3) Cochlear BI300 plus OSI300 with spacer, (4) Cochlear BI300 plus OSI300 without magnet or spacer using the institutional head and inner ear protocol and with metal artefact reduction (MAVRIC SL). Blinded image scoring was performed independently by three radiologists.

RESULTS

Excluding diffusion and susceptibility weighted imaging (DWI and SWI) anatomical structures contralateral to the OSI300 implant were highly visible in all conditions. Artefact size was clearly improved after magnet removal and with metal artefact reduction technique.

DISCUSSION: The OSI300 system produces image artefacts in both 1.5 and 3.0 Tesla MR imaging and, as previous research has reported, with the coil magnet removed, offers the least amount of distortion and artefact.

CONCLUSION

While certain sequences such as DWI, FLAIR and SWI showed notably reduced diagnostic value, the MAVRIC SL sequences proved to reduce implant artefact resulting in diagnostic quality examinations.