Design of a birdcage array for lower extremity angiography
Design of a birdcage array for lower extremity angiography
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DOI：
10.1002/jmri.21042
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发表时间：
2007-09-01
影响因子：
4.4
通讯作者：
Wang, Yi
中科院分区：
文献类型：
--
作者：
Brown, Ryan;Prince, Martin R.;Wang, Yi
目的：探讨由多个鸟笼组成的线圈阵列在下肢推注追踪磁共振血管造影（MRA）中的应用。材料与方法：原型由四个鸟笼线圈组成；两个相邻的鸟巢用于大腿成像，两个相邻的鸟巢用于小腿成像。使用共享电容器实现相邻线圈之间的去耦。使用台架测量和 MR 图像来评估解耦方案。对鸟笼阵列和四个市售线圈之间的图像信噪比 (SNR) 进行了比较。对 10 名志愿者进行了对比增强成像实验，并模拟了并行成像。这项研究得到了当地机构审查委员会的批准，并获得了每位志愿者的书面知情同意书。结果：电容去耦减少了信号泄漏。与四元件阵列相比，小牛鸟笼的信噪比提高了 84%，而大腿鸟笼的信噪比提高了 53%。血管造影图像说明了线圈在外周 MRA 中的实用性。并行成像以两倍的缩减因子进行了验证。结论：鸟笼线圈由于其均匀的灵敏度、良好的信噪比和圆柱形几何形状而被证明对于下肢成像很有价值。使用共享电容器控制耦合，允许单个鸟笼单独包围每条腿，为外围成像的信号接收提供了一种新颖的方法。
Purpose: To investigate the application of a coil array consisting of multiple birdcages for bolus chase magnetic resonance angiography (MRA) of the lower extremities.Materials and Methods: The prototype consisted of four birdcage coils; two adjacent birdeages for thigh imaging, and two for calf imaging. Decoupling between adjacent coils was achieved using shared capacitors. Bench measurements and MR images were used to evaluate the decoupling scheme. Image signal-to-noise ratios (SNR) were compared between the birdcage array and four commercially available coils. Contrast-enhanced imaging experiments were performed on 10 volunteers and parallel imaging was simulated. This study was approved by the local institutional review board and written informed consent was obtained from each volunteer.Results: Capacitive decoupling resulted in a reduction in signal leakage. The calf birdcages provided an 84% SNR improvement over a four element array, while the thigh birdcages provided a 53% improvement. Angiographic images illustrated the utility of the coil for peripheral MRA. Parallel imaging was demonstrated with a two-fold reduction factor.Conclusion: Birdcage coils were demonstrated to be valuable for lower extremity imaging due to their homogenous sensitivity, good SNR, and cylindrical geometry. Coupling was controlled using shared capacitors that allowed a single birdcage to encompass each leg individually, providing a novel approach to signal reception for peripheral imaging.