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（由适用提供）：越来越多的研究表明，磁共振成像（MRI）的质量和安全性可以通过仔细的选择和具有高电介电常数的材料或高介电常数材料（HPMS）的仔细选择和排列可显着改善，或者可以在射射线射频（RF）周围空间中的高介电常数材料（HPM）（HPMS）。通过战略使用，这些材料可以通过位移电流的效果转换RF线圈和患者周围空间中无用的电场能量。这些位移电流比单独的离散电线中的导电电流更多的磁场来源，并且比不损害安全性的离散电线更接近受试者。在接收中，净结果是较高的SNR（在许多实验和模拟中大约为40％），而传播中受试者吸收的RF能量明显较小。鉴于MRI的SNR限制性质，要越来越高的野外强度（包括找到NBTI的超导替代品）的多项重大成本，并且可以在所有现有的扫描仪中使用HPMS来实现SNR的直接增强，从而追求这项工作对于现有和未来系统的MRI的进步至关重要。我们建议开发薄而固体的HPM，这些HPM适合当前由塑料线圈形成器中最新的临床线圈中占用的空间，并将它们集成到新的线圈设计中。这是最终结果将不超过现有的临床线圈，并且导电线圈将与受试者相距不远。初步模拟和实验证明了这种方法的可行性。数值模拟考虑SNR和患者加热（SAR）将根据所需的特性和形状指导材料的设计。其他等效的RF头线线圈，有或没有HPM的掺入，将用于7T研究和3T临床系统。在两个现场强度下，将在许多临床相关方案中比较带有和没有HPM的线圈的性能。性能也将与现有的最新临床线圈进行比较。我们期望在两个田间强度下的SNR和SAR的降低。这项研究的成功完成将克服众多障碍，用于实践，常规使用HPM，并在未来和现有MRI系统上取得显着（约40％）的SNR增长（约40％）。