Departamento de Fisica, Facultad de Ciencias, Universidad Nacional Autonoma de Mexico, CdMx 04510, Mexico.
Department of Physical Intelligence, Max Planck Institute for Intelligence Systems, Stuttgart 70569, Germany.
Biomed Phys Eng Express. 2024 Sep 3;10(5). doi: 10.1088/2057-1976/ad7265.
This study introduces a novel volume coil design that features two slotted end-plates connected by six rungs, resembling the traditional birdcage coil. The end rings are equipped with six evenly distributed circular slots, inspired by Mansfield's cavity resonator theory, which suggests that circular slots can generate a baseline resonant frequency. One notable advantage of this proposed coil design is its reduced reliance on electronic components compared to other volume coils, making it more efficient. Additionally, the dimensions of the coil can be theoretically computed in advance, enhancing its practicality. To evaluate the performance and safety of the coil, electromagnetic field and specific absorption rate simulations were simulated using a cylindrical saline phantom and the finite element method. Furthermore, a transceiver coil prototype optimized for 7 Tesla and driven in quadrature was constructed, enabling whole-body imaging of rats. The resonant frequency of the coil prototype obtained through experimental measurements closely matched the theoretical frequency derived from Mansfield's theory. To validate the coil design, phantom images were acquired to demonstrate its viability and assess its performance. These images also served to validate the magnetic field simulations. The experimental results aligned well with the simulation findings, confirming the reliability of the proposed coil design. Importantly, the prototype coil showcased significant improvements over a similarly-sized birdcage coil, indicating its potential for enhanced performance. The noise figure was lower in the prototype versus the birdcage coil (-= 0.7). Phantom image data were also used to compute the image SNR, giving SNR/SNR= 34.36/24.34. By proving the feasibility of the coil design through successful rat whole-body imaging, the study provides evidence supporting its potential as a viable option for high-field MRI applications on rodents.
本研究介绍了一种新颖的容积线圈设计，其特点是两个带有六个梯级的开槽端板相连，类似于传统的鸟笼线圈。端环配备了六个均匀分布的圆形槽，这是受 Mansfield 空腔谐振器理论的启发，该理论表明圆形槽可以产生基准谐振频率。与其他容积线圈相比，这种提出的线圈设计的一个显著优点是它对电子元件的依赖程度降低，因此效率更高。此外，线圈的尺寸可以提前进行理论计算，从而提高其实用性。为了评估线圈的性能和安全性，使用圆柱生理盐水模型和有限元方法对电磁场和比吸收率进行了模拟。此外，还构建了一个针对 7T 进行优化并采用正交驱动的收发器线圈原型，实现了大鼠的全身成像。通过实验测量获得的线圈原型的谐振频率与 Mansfield 理论得出的理论频率非常吻合。为了验证线圈设计，采集了幻影图像以证明其可行性和评估其性能。这些图像还用于验证磁场模拟。实验结果与模拟结果非常吻合，证实了所提出的线圈设计的可靠性。重要的是，原型线圈与类似尺寸的鸟笼线圈相比显示出了显著的性能提升，表明其具有增强性能的潜力。原型线圈的噪声系数比鸟笼线圈低（-= 0.7）。还使用幻影图像数据计算了图像 SNR，得出 SNR/SNR= 34.36/24.34。通过成功进行大鼠全身成像证明了线圈设计的可行性，该研究为其在啮齿动物高场 MRI 应用中作为可行选择提供了证据支持。
