Magnetic Resonance Imaging Artifact Associated With Transcutaneous Bone Conduction Implants: Cholesteatoma and Vestibular Schwannoma Surveillance

Abstract

ObjectiveTo evaluate the magnetic resonance (MR) image artifact and image distortion associated with the two transcutaneous bone conduction implants currently available in the United States.Study DesignCadaveric study.MethodsTwo cadaveric head specimens (1 male, 1 female) were unilaterally implanted according to manufacturer guidelines and underwent MR imaging (General Electric and Siemens 1.5 T scanners) under the following device conditions: (1) no device, (2) Cochlear Osia with magnet and headwrap, (3) Cochlear Osia without magnet, and (4) MED‐EL Bonebridge with magnet. Maximum metal mitigation techniques were employed in all conditions, and identical sequences were obtained. Blinded image scoring (diagnostic vs nondiagnostic image) was performed by experienced neuroradiologists according to anatomical subsites.ResultsAll device conditions produced artifact and image distortion. The Osia with magnet produced diagnostic T1‐ and T2‐weighted images of the ipsilateral temporal bone, however, non‐echo planar imaging diffusion‐weighted imaging (DWI) was nondiagnostic. The Osia without magnet scanned on the Siemens MR imaging demonstrated the least amount of artifact and was the only condition that allowed for diagnostic imaging of the ipsilateral temporal bone on DWI. The Bonebridge produced a large area of artifact and distortion with the involvement of the ipsilateral and contralateral temporal bones.ConclusionIn summary, of the three device conditions (Osia with magnet, Osia without magnet, and Bonebridge), Osia without magnet offered the least amount of artifact and distortion and was the only condition in which diagnostic DWI was available for the middle ear and mastoid regions on the Siemens MR imaging scanner.

Temporal bone management in external and middle ear carcinoma

“…If considering placement of transcutaneous boneconduction implants, it is important to consider implications on postoperative imaging surveillance of carcinoma or development of cholesteatoma. Recent work demonstrated substantial imaging artifact associated with transcutaneous bone-conduction implants when attempting diffusion-weighted imaging for cholesteatoma surveillance, and protocol modifications are required for adequate imaging using T1/ T2-weighted sequences [30]. Furthermore, placement of a transcutaneous bone-conduction implant introduces the potential for radiation scatter or attenuation [31], although this has not been studied specifically for the newer transcutaneous bone-conduction implants to date.…”

Clinical experience: Simultaneous bilateral Osia implantation in children with microtia

“…3 Had there been any concerns about need for future MRI of the head (e.g., cholesteatoma in a patient with stenosis rather than atresia or an underlying syndrome) we would recommend doing this first as the metal artefact from the device makes future MRI assessment of the middle ear impossible without prior removal. 4 We ask all our patients to review a dummy device and processor held against the head in the mirror to ensure they are happy with the appearance. In our experience, the device is larger than they expect, particularly for children.…”