人工耳蜗植入术后高场强磁共振检查安全性研究

A Study on effects of High Power MRI Examination on Cochlear Implants

目的研究人工耳蜗植入(Cochlear implantation,CI)者行高场强磁共振(Magnetic Resonance Imaging,MRI)检查的安全性,及高场强MRI检查对CI者聆听效果的影响。方法 4例CI者行高场强MRI检查(2例1.5T、2例3.0T)。测试其在检查后的助听听阈结果及双音节、安静下句子言语识别率得分。1.5T场强下检查的患者(男性45岁),为其植入体部位进行加压包扎,未移出植入体内部磁铁。1.5T场强下进行颅脑检查的患者(男性28岁),以及在3.0T场强下检查的2例患者(男性17岁及女性33岁),经局部麻醉在手术室取出人工耳蜗植入体磁铁,检查结束后原位植入更换的磁铁。结果 4例患者在高场强下顺利完成MRI检查,影像结果满足临床诊断要求,检查中无异常情况发生。4例患者在检查后均无不适感。测试在1.5T场强下检查后的45岁患者助听听阈结果在25dB HL~35dB HL,检查后双音节识别率为84%,安静环境句子识别率为90%。测试在3.0T场强下检查后的2例患者助听听阈结果在30dB HL~45dB HL,检查后双音节识别率为70%和68%,安静下句子识别率为82%和78%。结论 CI是MRI检查的相对禁忌,CI患者在严格评估和监测下可顺利完成高场强MRI检查,检查后人工耳蜗设备正常工作,且患者无不适反应。

Objective To study the safety of high power MRI examination for cochlear implant recipients and its post-examination effects on hearing through cochlear implant(CI). Methods Four patients with CI needing MRI examination were recruited and completed imaging at 1.5 T(two cases) or 3.0 T(two cases), respectively. Spondee word and sentence speech recognition in quiet was tested after their MRI examination. In one patient examined at 1.5 T(male, 44 years old), pressure dressing was applied without removing the magnet, while in the rest three patients undergoing cerebral imaging, including a 28 years old male(at 1.5 T), a 17 years old male and a 33 years old female, the magnet was removed under local anesthesia and a new magnet re-implanted in situ after the MRI examination. Results MRI images were satisfactory and examination uneventful in all four patients. Post-MRI hearing thresholds on CI were 25-35 dB HL with spondee word recognition at 84%, and sentence recognition at 90% in quiet in the patient without magnet removal,while the post-MRI thresholds on CI were 30-45 dB HL with spondee word recognition at 70% and 68% and sentence recognition at 82% and 78%, respectively, in the 2 patient imaged at 3.0 T. No discomfort was reported in these two patients. Conclusion CI is a relative contraindication for MRI examination. Cochlear implant patients can successfully complete high-power MRI examination under strict evaluation and monitoring with no discomfort and normally working cochlear implant equipment after examination.