Next-Generation RF Coils with High-Permittivity Material for Improved Performance in MRI

采用高介电常数材料的下一代射频线圈可提高 MRI 性能

• 批准号: 9007398
• 负责人: Christopher M Collins
• 金额: $ 51.79万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-21 至 2020-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9007398
• 关键词: Affect; Area; Biomedical Research; Body Image; Clinical; Clinical Research; Communication; Computer software; Computer-Aided Design; Coupling; Development; Diagnosis; Ensure; Environment; Face; Future; Head; Heating; Human; Human body; Image; Imaging technology; Knee; Lead; Limb structure; Liquid substance; Magnetic Resonance Imaging; Magnetism; Measurement; Measures; Mechanics; Medical; Medical Research; Methods; Military Personnel; Modeling; Nature; Noise; Patients; Performance; Physiologic pulse; Positioning Attribute; Process; Production; Property; Protocols documentation; Research; Resolution; Safety; Sampling; Scheme; Shapes; Signal Transduction; Solid; Source; Speed; System; Techniques; Technology; Work; base; clinically relevant; cost; cryogenics; design; electric field; electrical property; experience; human subject; imaging system; improved; interest; magnetic field; next generation; novel; public health relevance; radiofrequency; research study; simulation; transmission process; wasting

 DESCRIPTION (provided by applicant): A growing number of studies show that the quality and safety of Magnetic Resonance Imaging (MRI) can be significantly improved with careful selection and arrangement of materials having a high electric permittivity, or High Permittivity Materials (HPMs) in the space around the radiofrequency (RF) coil and the human subject. With strategic use, these materials act to convert otherwise useless electric field energy in the space surrounding the RF coil and patient into useful magnetic field energy through the effects of displacement currents. These displacement currents are more distributed sources of magnetic fields than are the conductive currents in the discrete wires alone, and can be closer to the subject than the discrete wires improving the sensitivity without compromising safety. The net result is higher SNR (by about 40% in many experiments and simulations) in reception and significantly less RF energy absorbed by the subject in transmission. Given the SNR-limited nature of MRI, the multiple significant costs of going to ever-higher field strengths (including finding superconductive alternatives to NbTi), and the fact that HPMs can be used in all existing scanners for an immediate boost in SNR, pursuing this work is critical to the advancement of MRI on existing and future systems. We propose to develop thin, solid HPMs that will fit within the space that is currently occupied by the plastic coil formers in state-of-the-art clinical coils and integrate them into new coil designs. Thus, the final result will be no larger than existing clinical coils and the conducting coils will be no further from the subject. Preliminary simulation and experiments demonstrate the feasibility of this approach. Numerical simulations considering both SNR and patient heating (SAR) will guide the design of the materials both in terms of desired properties and shape. Otherwise equivalent RF head coils with and without the incorporation of HPMs will be constructed for use on 7T research and 3T clinical systems. The performance of coils with and without HPMs will be compared in a number of clinically relevant protocols at both field strengths. Performance will also be compared to existing state-of-the-art clinical coils. We expect significant gains in SNR and reduction in SAR at both field strengths. Successful completion of this research will overcome numerous obstacles to practical, routine use of HPMs and make significant (~40%) gains in SNR possible on both future and existing MRI systems.

 描述（由申请人提供）：越来越多的研究表明，通过仔细选择和布置具有高介电常数的材料或高介电常数材料（HPM），可以显着提高磁共振成像（MRI）的质量和安全性。射频 (RF) 线圈和人体周围的空间通过战略性使用，这些材料可以通过位移效应将射频线圈和患者周围空间中原本无用的电场能量转换为有用的磁场能量。这些位移电流是比单独的分立导线中的传导电流更分散的磁场源，并且可以比分立导线更接近对象，从而提高了灵敏度，而不会影响安全性。在许多实验和模拟中，接收中的射频能量减少了 40%，而在传输中，受试者吸收的射频能量明显减少。鉴于 MRI 的 SNR 限制，采用更高的场强（包括寻找超导替代品）的成本会很高。 NbTi），而且 HPM 可用于所有现有扫描仪以立即提高 SNR，因此开展这项工作对于现有和未来系统上 MRI 的进步至关重要，我们建议开发适合的薄型、坚固的 HPM。目前最先进的临床线圈中塑料线圈架所占用的空间，并将其集成到新的线圈设计中，因此，最终结果将不会比现有的临床线圈更大，并且导电线圈也不会更大。来自主题。初步模拟和实验证明了这种方法的可行性，同时考虑了 SNR 和患者加热 (SAR) 的数值模拟将指导材料的设计，无论是否包含 HPM，都将指导材料的设计。将构建用于 7T 研究和 3T 临床系统 具有和不具有 HPM 的线圈的性能将在两个场强的许多临床相关协议中进行比较。我们预计，成功完成这项研究将克服 HPM 实际、常规使用的诸多障碍，并取得显着的收益 (~40%)。未来和现有 MRI 系统的信噪比 (SNR) 都是可能的。