Construction and modeling of a reconfigurable MRI coil for lowering SAR in patients with deep brain stimulation implants.
Construction and modeling of a reconfigurable MRI coil for lowering SAR in patients with deep brain stimulation implants.
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DOI：
10.1016/j.neuroimage.2016.12.056
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发表时间：
2017-02-15
期刊：
影响因子：
5.7
通讯作者：
Wald LL
中科院分区：
文献类型：
--
作者：
Golestanirad L;Iacono MI;Keil B;Angelone LM;Bonmassar G;Fox MD;Herrington T;Adalsteinsson E;LaPierre C;Mareyam A;Wald LL
对深部脑模拟 (DBS) 植入物患者进行术后 MRI 有助于评估并发症和诊断合并症，但由于严格的安全限制和责任风险，超过三分之一的医疗中心不会对该患者群体进行 MRI。提出了一种新的可重构磁共振成像头线圈系统，该系统由可旋转线偏振鸟笼发射器和紧密配合的 32 通道接收阵列组成，用于对 DBS 植入患者进行低 SAR 成像。该新颖系统的工作原理是生成一个低电场强度区域，并将其引导至与 DBS 引导轨迹一致。我们证明，在一组 9 个患者衍生的真实 DBS 导联轨迹中，与市售圆极化线圈相比，新线圈系统大大降低了 DBS 电极周围的 SAR 放大。我们还表明，可以从 B1+ 场图上的图像伪影中可靠地识别最佳线圈配置。我们的初步结果表明，这样的系统可能为未来 DBS 患者的高分辨率成像提供可行的解决方案。在将新型线圈系统用于接受 DBS 植入的患者之前，需要更多数据来量化安全限制并推荐成像方案。
Post-operative MRI of patients with deep brain simulation (DBS) implants is useful to assess complications and diagnose comorbidities, however more than one third of medical centers do not perform MRIs on this patient population due to stringent safety restrictions and liability risks. A new system of reconfigurable magnetic resonance imaging head coil composed of a rotatable linearly-polarized birdcage transmitter and a close-fitting 32-channel receive array is presented for low-SAR imaging of patients with DBS implants. The novel system works by generating a region with low electric field magnitude and steering it to coincide with the DBS lead trajectory. We demonstrate that the new coil system substantially reduces the SAR amplification around DBS electrodes compared to commercially available circularly polarized coils in a cohort of 9 patient-derived realistic DBS lead trajectories. We also show that the optimal coil configuration can be reliably identified from the image artifact on B1+ field maps. Our preliminary results suggest that such a system may provide a viable solution for high-resolution imaging of DBS patients in the future. More data is needed to quantify safety limits and recommend imaging protocols before the novel coil system can be used on patients with DBS implants.