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(申请人提供)：越来越多的研究表明，通过仔细选择和排列射频(RF)线圈和人体周围空间的高介电常数材料或高介电常数材料(HPMS)，可以显著提高磁共振成像(MRI)的质量和安全性。在战略用途上，这些材料通过位移电流的影响，将射频线圈和患者周围空间中原本无用的电场能量转化为有用的磁场能量。与单独在离散导线中的导电电流相比，这些位移电流是更分散的磁场来源，并且可以比离散导线更接近对象，从而在不影响安全性的情况下提高了灵敏度。最终结果是更高的接收信噪比(在许多实验和模拟中提高了约40%)，并显著降低了受试者在传输中吸收的射频能量。鉴于核磁共振具有信噪比受限的性质，获得更高场强的多重重大成本(包括寻找NbTi的超导替代品)，以及HPMS可以在所有现有扫描仪中使用以立即提高信噪比的事实，开展这项工作对于在现有和未来系统上推进核磁共振至关重要。我们建议开发薄的、固体的HPMS，它将适合目前由最先进的临床线圈中的塑料线圈成形器占据的空间，并将它们整合到新的线圈设计中。因此，最终的结果将不会比现有的临床线圈大，并且传导线圈将不会离对象更远。初步的仿真和实验证明了该方法的可行性。同时考虑信噪比和患者加热(SAR)的数值模拟将在所需的性能和形状方面指导材料的设计。否则，将构建用于7T研究和3T临床系统的包含和不包含HPMS的等效射频磁头线圈。在两种磁场强度下，使用和不使用HPMS的线圈的性能将在许多临床相关方案中进行比较。性能还将与现有最先进的临床线圈进行比较。我们预计，在这两个领域的优势下，SNR将显著提高，而SAR将显著降低。这项研究的成功完成将克服HPMS实际、常规使用的众多障碍，并使未来和现有MRI系统的SNR显著提高(~40%)。