A Prospective Study of Pain From Magnetic Resonance Imaging With Cochlear Implant Magnets In Situ.

OBJECTIVE

To describe changes in pain associated with magnetic resonance imaging (MRI) with cochlear implant magnets in place.

STUDY

DESIGN

Prospective, single-arm study.

SETTING

Tertiary referral center.

SUBJECTS: Adults with cochlear implants requiring MRI.

INTERVENTION: Tight head wrapping over internal device during MRI.

MAIN OUTCOME MEASURES: Change in pain score using an 11-point visual analogue scale, duration/completion of MRI, body mass index (BMI), quality of pain, status of the skin, functioning of implant, displacement/polarity change of magnet, willingness to repeat MRI without magnet removal.

RESULTS

A total of 27 subjects obtained 42 MRI scans. Subjects were 59% male with age range of 21 to 80 years. All three manufacturers were represented. Forty-eight percent of scans imaged the brain/head while 52% imaged other sites. The mean individual change in pain was 3.9 (SD 3.5, range 0-10). The pain was most commonly described as "pressure", "heat", or "sharp". There was no significant correlation between change in pain and scan duration, BMI, or body part imaged. Eighty-eight percent of the scans were completed. There were no skin complications except temporary erythema (29%) and there were no magnet/device complications. Eighty-eight percent said they would undergo MRI without magnet removal again.

CONCLUSION

The pain associated with obtaining an MRI without cochlear implant magnet removal is highly variable. Increase in pain is not related to duration of MRI scan, body part imaged, or BMI. Despite the pain, almost all patients prefer MRI scanning with the magnet in place, to avoid two surgical procedures.