Quantification of Imaging Artifact in MRI-Conditional Cochlear Implants

Tuesday, October 3, 2023

5:39 PM - 5:45 PM East Coast USA Time

Location: 104BC

Presenting Author(s)

Samuel John Cler, MD

Resident
Washington University in St. Louis
St. Louis, MO, United States

Co-Author(s)

SY

Stephanie J. Youssef, MD

Resident
Washington University in St. Louis
Clarendon Hills, IL, United States
CK

Cameron Koch, MD

Mallinckrodt Institute of Radiology, USA
Matthew S. Parsons, MD

Associate Professor of Radiology
Mallinckrodt Institute of Radiology
Saint Louis, MO, United States

Senior Author(s)

Cameron C. Wick, MD

Associate Professor
Washington University
Saint Louis, MO, United States

Disclosure(s):

Samuel John Cler, MD: No relevant relationships to disclose.

Introduction: All three FDA-approved cochlear implant (CI) manufacturers have released MRI-conditional internal receiver magnets. To date, there lacks a critical comparison of artifact associated with these magnets.

Methods: This retrospective review included patients with an MRI-conditional CI who underwent MRI from 2012 through 2022 at a single center. MRI compatibility was determined via CI manufacturer specifications. Patients of any age were included. On T2 axial imaging, artifact not reaching the lateral ventricle was mild, between the lateral ventricle and midline was moderate, and crossing the midline was severe. Ability to assess the internal auditory canal (IAC) was determined by two neuroradiologists. Device manufacturer was the independent variable. MRI artifact was the dependent variable. For bilateral CIs, artifact was assessed independently on each side. Statistical analysis was limited to Cochlear Ltd. and Med-El devices due to sample size.

Results: 76 MRI scans across 33 patients (15 female) with a median age of 38 years (inter-quartile range 16-57 years) were included. 7 patients had bilateral CIs. This cohort included 14 Cochlear Ltd. CIs, 23 Med-El CIs, and 3 Advanced Bionics CIs. For Cochlear Ltd. devices, 7% (1/15) had mild artifact, 80% (12/15) had moderate artifact, and 13% (2/15) had severe artifact. For Med-El devices, 0% (0/58) had mild artifact, 71% (41/58) had moderate artifact, and 29% (17/58) had severe artifact. For Advanced Bionic devices, 0% (0/3) had mild artifact, 0% (0/3) had moderate artifact, and 100% (3/3) had severe artifact. Imaging artifact severity was similar between Cochlear Ltd. and Med-El devices (p=0.325).

Conclusions: Imaging artifact and ability to assess the IAC is a key consideration for patients undergoing cochlear implantation with known intracranial pathology. MRI-conditional CI internal receivers across FDA-approved manufacturers displayed similar artifact profiles, although further characterization of this phenomena is needed. To date, this is the first study to compare all three device magnets and does not indicate diagnostic superiority of one manufacturer.