MRI in Patients with Cochlear Implants

Magnetic resonance imaging may cause pain and magnet displacement in patients who have cochlear implants, according to a study published online in JAMA Otolaryngology-Head & Neck Surgery.

Researchers from South Korea performed a small review study of the medical records of 18 patients (seven male, 11 female) with cochlear implants (CIs) who underwent an MRI between 2003 and 2014, to assess the adverse events during MRI in patients with CIs and to investigate the safety and diagnostic efficiency of MRI in patients with CIs with internal magnets.

Twelve patients underwent imaging of the brain and all 18 patients underwent imaging of other parts of the body. Sixteen patients were scanned using a 1.5-T scanner and two with a 3.0-T scanner. Five patients underwent MRI under general anesthesia because they were too young to tolerate the scans.

A total of 25 of the 30 scans were completed without complications, however, MRIs were not completed for five patients because of complaints of extreme pain, despite having been fit with protective head bandages. One patient was awakened from anesthesia by the pain. One patient experienced magnet displacement. The authors noted that another patient tolerated the pain and discomfort for the third scan, but experienced magnet polarity reversal. All adverse events or complications were found among the patients who were scanned with the 1.5-T scanner. Neither patient who underwent scanning with the 3.0-T scanner were bandaged, and they only reported some discomfort.

Hearing-related performance was unaffected in three CI patients who had major adverse events associated with MRI scanning.

 “Our data clearly demonstrate that a significant proportion of patients experienced discomfort or pain during the MRI process and were unable to complete the scans. Therefore, in addition to device safety and image quality, patient comfort should be considered when performing MRI procedures,” the authors note.

The authors concluded that patients with CIs must fully understand not only the potential complications but also the potential discomforts that they may experience during the scan.

These findings have reinforced a strong lesson to radiologists, wrote Emanuel Kanal, MD, in a related commentary. “Their reminder to consider not just mere safety but also morbidity and acceptability to the patient, is refreshing indeed. This should be added to our list of considerations prior to determining any risk-benefit assessment and patient scan recommendations regarding exposure of patients with implants to MRI environments.”