Pain, Safety, and Image Quality of Magnetic Resonance Imaging With Cochlear Implants: A Prospective Trial.

OBJECTIVE

To evaluate whether rotating cochlear implant (CI) magnets improve patient comfort and preserve scan usability during magnetic resonance imaging (MRI).

STUDY

DESIGN

Prospective cohort study.

SETTING

Two tertiary academic centers.

METHODS

Adult patients with CIs who underwent MRI of any body region were included. The primary outcome was the mean change in pain score from baseline (before any study procedure) to the highest reported pain level during MRI with a CI magnet in place. Secondary outcomes included patient-reported survey responses regarding their MRI experience and the interpretability of the brain MRI scans involving rotating magnets, as assessed by two independent, blinded neuroradiologists.

RESULTS

Twenty-three MRI scans (21 patients) with CIs were analyzed. Eleven scans (47.8%) involved implants containing internal magnets designed to self-align with the magnetic field. The mean pain-score difference unrelated to headwrap use was significantly lower for rotating magnet devices than fixed magnets (0.7 vs 4.0, P = .02). No magnet displacement or depolarization occurred. In six MRI brain sequences, the mean maximal signal-loss artifact measured 6.1 cm (SD 1.2 cm) on axial images for rotating magnet devices. When assessing if the MRI could answer the question for which the scan was ordered, 100% of responses (n = 12) ranged from slightly agree to strongly agree. The majority of patients (70.0%) indicated they would undergo another MRI if medically necessary.

CONCLUSION

CIs containing rotatable magnets reduce MRI-related pain compared to those with fixed magnets. Although the magnets produce a measurable artifact, it does not substantially compromise scan utility in the majority of cases.