Eichler Theda, Ibrahim Ahmed, Riemann Conrad, Scholtz Lars Uwe, Gehl Hans Björn, Goon Peter, Sudhoff Holger, Todt Ingo
Department of Otolaryngology, Head and Neck Surgery, Medical School OWL, Bielefeld University, Klinikum Bielefeld, 33502 Bielefeld, Germany.
Department of Radiology, Medical School OWL, Bielefeld University, Klinikum Bielefeld, 33502 Bielefeld, Germany.
Brain Sci. 2022 Oct 19;12(10):1406. doi: 10.3390/brainsci12101406.
The approval process for MRI safety of implants includes physical observations and an experimental evaluation in artificial settings to simulate the in vivo effect. This contains the observation of temperature changes and artificial current generation by the magnetic field. From these findings, the safety of an implant and its effect on the patient can be estimated. MRI safety is based on an in vivo evaluation of adverse events after the approval process, but an actual analysis of the effect on different tissues is not followed. The effect of MRI scanning in cochlea implantees on their residual hearing as the correlate of the hair cell function is so far unknown, therefore the aim of the present study was to observe the effect of 3 T MRI on the residual hearing of cochlea implantees.
In this prospective study, we performed a 3 T MRI T2 2D MS Drive sequence in eight cochlea-implanted ears. Before and after the MRI scan, a bone conduction pure tone audiogram (BC PTA) was performed. All cochlea implantees had a pre-scanning threshold of low frequency residual hearing between 20 dB and 65 dB.
Low frequency mean residual hearing was not affected by the 3 T T2 2D MS Drive sequence. We observed a pre-scanning threshold at 250 Hz of 42.9 (SD 3.9) dB and for 500 Hz 57.1 (SD 6.4) dB. Post-scanning BC PTA was for 250 Hz 42.1 (SD 3.9) dB and for 500 Hz 57.1 (SD 5.7) dB.
3 T MRI scanning has no significant functional effect on the hair cells in cochlea implantees in low frequencies with a T2 2D MS Drive sequence.
植入物的MRI安全性批准过程包括物理观察以及在人工环境中进行实验评估以模拟体内效应。这包括观察温度变化和磁场产生的人工电流。根据这些结果，可以评估植入物的安全性及其对患者的影响。MRI安全性基于批准过程后对不良事件的体内评估，但并未对其对不同组织的影响进行实际分析。迄今为止，尚不清楚MRI扫描对人工耳蜗植入者残余听力（作为毛细胞功能的相关指标）的影响，因此本研究的目的是观察3T MRI对人工耳蜗植入者残余听力的影响。
在这项前瞻性研究中，我们对8只植入人工耳蜗的耳朵进行了3T MRI T2 2D MS Drive序列扫描。在MRI扫描前后，进行了骨导纯音听力图（BC PTA）检查。所有人工耳蜗植入者的低频残余听力预扫描阈值在20dB至65dB之间。
低频平均残余听力不受3T T2 2D MS Drive序列的影响。我们观察到250Hz的预扫描阈值为42.9（标准差3.9）dB，500Hz为57.1（标准差6.4）dB。扫描后的BC PTA在250Hz时为42.1（标准差3.9）dB，500Hz时为57.1（标准差5.7）dB。
对于人工耳蜗植入者，采用T2 2D MS Drive序列的3T MRI扫描在低频时对毛细胞没有显著的功能影响。
