University Department of Diagnostic and Interventional Neuroradiology, Inselspital Bern, Bern, Switzerland.
University Department of Otorhinolaryngology, Head & Neck Surgery, Inselspital Bern, Bern, Switzerland; ARTORG Center for Biomedical Engineering Research, University of Bern, Bern, Switzerland.
PLoS One. 2015 Jul 22;10(7):e0132483. doi: 10.1371/journal.pone.0132483. eCollection 2015.
Cochlear implants (CIs) are standard treatment for postlingually deafened individuals and prelingually deafened children. This human cadaver study evaluated diagnostic usefulness, image quality and artifacts in 1.5T and 3T magnetic resonance (MR) brain scans after CI with a removable magnet.
Three criteria (diagnostic usefulness, image quality, artifacts) were assessed at 1.5T and 3T in five cadaver heads with CI. The brain magnetic resonance scans were performed with and without the magnet in situ. The criteria were analyzed by two blinded neuroradiologists, with focus on image distortion and limitation of the diagnostic value of the acquired MR images.
MR images with the magnet in situ were all compromised by artifacts caused by the CI. After removal of the magnet, MR scans showed an unequivocal artifact reduction with significant improvement of the image quality and diagnostic usefulness, both at 1.5T and 3T. Visibility of the brain stem, cerebellopontine angle, and parieto-occipital lobe ipsilateral to the CI increased significantly after magnet removal.
The results indicate the possible advantages for 1.5T and 3T MR scanning of the brain in CI carriers with removable magnets. Our findings support use of CIs with removable magnets, especially in patients with chronic intracranial pathologies.
人工耳蜗植入（CIs）是治疗后天失聪和先天失聪患者的标准治疗方法。本项人体尸体研究评估了可移除磁铁植入人工耳蜗后 1.5T 和 3T 磁共振（MR）脑部扫描的诊断有用性、图像质量和伪影。
在 5 具带有 CI 的尸体头颅中，分别在 1.5T 和 3T 下评估了 3 项标准（诊断有用性、图像质量、伪影）。对原位带磁和不带磁的脑磁共振扫描进行了分析。由两名盲法神经放射科医生对标准进行分析，重点关注图像失真和获得的 MR 图像诊断价值的局限性。
原位带磁的 MR 图像均受到 CI 引起的伪影的影响。移除磁铁后，在 1.5T 和 3T 下，MR 扫描均显示出明确的伪影减少，图像质量和诊断有用性显著改善。同侧 CI 的脑干、桥小脑角和顶枕叶的可见度显著增加。
结果表明，对于带可移除磁铁的 CI 患者，1.5T 和 3T 的脑磁共振扫描可能具有优势。我们的研究结果支持使用带可移除磁铁的 CI，尤其是在患有慢性颅内病变的患者中。
