PDF(Pubmed)
Abstract：
In the field of ultra-high field MR imaging, the challenges associated with higher frequencies and shorter wavelengths necessitate rigorous attention to multichannel array design. While the need for such arrays remains, and efforts to increase channel counts continue, a persistent impediment-inter-element coupling-constantly hinders development. This coupling degrades current and field distribution, introduces noise correlation between channels, and alters the frequency of array elements, affecting image quality and overall performance. The goal of optimizing ultra-high field MRI goes beyond resolving inter-element coupling and includes significant safety considerations related to the design changes required to achieve high-impedance coils. Although these coils provide excellent isolation, the higher impedance needs special design changes. However, such changes pose a significant safety risk in the form of strong electric fields across low-capacitance lumped components. This process may raise Specific Absorption Rate (SAR) values in the imaging subject, increasing power deposition and, as a result, the risk of tissue heating-related injury. To balance the requirement of inter-element decoupling with the critical need for safety, we suggest a new solution. Our method uses high-dielectric materials to efficiently reduce electric fields and SAR values in the imaging sample. This intervention tries to maintain B1 efficiency and inter-element decoupling within the existing array design, which includes high-impedance coils. Our method aims to promote the full potential of ultra-high field MRI by alleviating this critical safety concern with minimal changes to the existing array setup.
摘要：
在超高场磁共振成像领域,与更高的频率和更短的波长相关的挑战需要严格注意多通道阵列设计。虽然仍然需要这样的阵列，继续努力增加频道数量，持续的障碍-元素间耦合-不断阻碍发展。这种耦合降低了电流和磁场分布，引入通道之间的噪声相关性，并改变数组元素的频率，影响图像质量和整体性能。优化超高场MRI的目标超出了解决元件间耦合的范围，并且包括与实现高阻抗线圈所需的设计更改相关的重大安全考虑。虽然这些线圈提供了极好的隔离，较高的阻抗需要特殊的设计变更。然而,这种变化在低电容集总元件两端的强电场形式中造成重大的安全风险。此过程可能会提高成像对象的比吸收率（SAR）值。增加功率沉积，因此,组织加热相关损伤的风险。为了平衡元件间去耦的要求与安全的关键需求，我们建议一个新的解决方案。我们的方法使用高介电材料来有效地降低成像样品中的电场和SAR值。这种干预试图在现有阵列设计中保持B1效率和元件间去耦，其中包括高阻抗线圈。我们的方法旨在通过对现有阵列设置进行最小的更改来减轻这种关键的安全问题，从而提高超高场MRI的全部潜力。
