Dynamic Multi-Coil B0 Shimming for Diagnostic MRI of Frontal Brain

用于额叶诊断 MRI 的动态多线圈 B0 匀场

• 批准号: 10095052
• 负责人: Christoph Juchem
• 金额: $ 53.8万
• 依托单位: COLUMBIA UNIV NEW YORK MORNINGSIDE
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-04-07 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10095052
• 关键词: Area; Automobile Driving; Brain; Brain imaging; Clinical; Complex; Computer-Aided Design; Coupling; Cranial Nerves; Cranial nerve diseases; Deposition; Development; Diagnostic; Diagnostic Imaging; Dropout; Echo-Planar Imaging; Electromagnetic Fields; Electromagnetics; Elements; Engineering; Environment; Eye; Future; Generations; Human; Hybrids; Image; Image Analysis; Iron; Magnetic Resonance Imaging; Maps; Mechanics; Medical Staff; Methods; Mission; Modeling; Morphologic artifacts; National Institute of Biomedical Imaging and Bioengineering; Ocular orbit; Optic Nerve; Optic Neuritis; Pathology; Patients; Performance; Phase; Predisposition; Prefrontal Cortex; Protocols documentation; Public Health; RF coil; Research; Safety; Shapes; Signal Transduction; Sinus; Slice; System; Techniques; Technology; Testing; Training; Translations; base; bench to bedside; brain tissue; clinical diagnostics; clinical imaging; cognitive function; design; healthy volunteer; imaging capabilities; improved; innovation; magnetic field; neuroimaging; novel; optic nerve disorder; radio frequency; safety assessment; simulation; tool; translational approach

PROJECT SUMMARY Fast gradient-echo MRI is the preferred method to visualize iron deposition in human brain tissue with susceptibility-weighted imaging (SWI), to map functional activity with echo-planar imaging (EPI) and to assess cranial nerve disorders with steady-state free precession (SSFP) MRI. However, its high susceptibility towards B0 magnetic field inhomogeneity poses serious challenges. Particularly strong and localized B0 deviations are observed above the sinus cavities in the prefrontal cortex (PFC), a brain area involved in many higher order cognitive functions, and the orbits comprising, among others, eyes and cranial nerves. Spatial image deformation and signal dropout induced by inhomogeneous B0 conditions can severely limit gradient-echo MRI quality and even render results useless, thereby fundamentally limiting its diagnostic potential. We have recently made major advances in the ability to obtain high levels of B0 homogeneity throughout the brain, including difficult-to-shim areas such as the PFC using a novel multi-coil hardware in combination with rapid B0 optimization methods and dynamic shimming. B0 shimming with this Dynamic Multi-Coil Technique (DYNAMITE) provides dramatically better B0 homogeneity than standard methods and in the future should close to completely eliminate B0 inhomogeneity as a problem. Our objective in this proposal is to combine DYNAMITE B0 shim with clinical RF technology to establish the first integrated multi-coil B0 and radio- frequency (MC/RF) setup dedicated to clinical diagnostics and workflow. Specific Aim 1: Electromagnetic field (EMF) simulations will be used to compare and optimize the potential of generating DYNAMITE B0 shim fields with a dedicated multi-coil B0 setup separate from the employed RF coil, by driving elements of an RF phased array with DC currents or a combination thereof in a hybrid approach, considering electromagnetic coupling and safety. Specific Aim 2: Computer-aided design (CAD) methods comprising electromagnetic, thermal and mechanical modeling will be used to realize the optimized MC/RF constellation for a clinical 3T MR scanner environment, providing diagnostic MRI capability in an efficient, reliable and safe fashion. Moreover, DYNAMITE B0 shimming tailored to routine clinical MRI protocols is expected to improve the overall image quality throughout the human brain compared to conventional spherical harmonic-based B0 shim technology. Specific Aim 3: DYNAMITE B0 shimming will be applied to diagnostic imaging of optic nerve diseases as part of routine protocols and workflow in a fully automated fashion transparent to the medical staff to test the hypothesis of enhanced diagnostic potential and a true clinical benefit due to MRI artifact mitigation. The approach is innovative because the best available B0 shimming and RF technologies are combined to provide unprecedented clinical MRI capabilities. The research is significant because it is expected to fundamentally leverage the diagnostic potential of gradient-echo MRI in the ventral PFC and orbits, setting the stage for widespread clinical use of state-of-the-art B0 shim technology and true translation from bench to bedside.

项目概要 快速梯度回波 MRI 是可视化人脑组织中铁沉积的首选方法 磁化率加权成像 (SWI)，通过平面回波成像 (EPI) 绘制功能活动图并评估 稳态自由进动 (SSFP) MRI 诊断颅神经疾病。然而，其对 B0磁场不均匀性带来了严峻的挑战。特别强烈且局部的 B0 偏差是 在前额皮质 (PFC) 的窦腔上方观察到，该区域涉及许多高级功能 认知功能，以及包括眼睛和脑神经等在内的眼眶。空间图像 B0 条件不均匀引起的变形和信号丢失会严重限制梯度回波 MRI 质量，甚至使结果变得无用，从而从根本上限制了其诊断潜力。我们有 最近在获得整个大脑高水平 B0 均匀性的能力方面取得了重大进展， 包括难以匀场的区域，例如使用新颖的多线圈硬件与快速 B0 相结合的 PFC 优化方法和动态匀场。使用这种动态多线圈技术进行 B0 匀场 (DYNAMITE) 提供比标准方法更好的 B0 均匀性，并且在未来应该 接近完全消除 B0 不均匀性问题。我们在该提案中的目标是结合 DYNAMITE B0 垫片采用临床射频技术，建立第一个集成多线圈 B0 和无线电 专用于临床诊断和工作流程的频率 (MC/RF) 设置。具体目标 1：电磁场 (EMF) 模拟将用于比较和优化生成 DYNAMITE B0 垫片场的潜力 通过驱动射频相控元件，使用与所使用的射频线圈分开的专用多线圈 B0 设置 考虑电磁耦合，采用混合方法的直流电流阵列或两者的组合 和安全。具体目标 2：计算机辅助设计 (CAD) 方法，包括电磁、热和 机械建模将用于实现临床 3T MR 扫描仪的优化 MC/RF 星座 环境，以高效、可靠和安全的方式提供诊断 MRI 能力。而且， 根据常规临床 MRI 方案定制的 DYNAMITE B0 匀场有望改善整体图像 与传统的基于球谐函数的 B0 垫片技术相比，整个人脑的质量得到了提高。 具体目标 3：DYNAMITE B0 匀场将作为视神经疾病诊断成像的一部分 以对医务人员透明的全自动方式制定常规方案和工作流程，以测试 由于 MRI 伪影减轻而增强诊断潜力和真正临床益处的假设。这 该方法是创新的，因为最好的可用 B0 匀场和射频技术相结合，提供 前所未有的临床 MRI 能力。这项研究意义重大，因为它有望从根本上 利用梯度回波 MRI 在腹侧 PFC 和眼眶中的诊断潜力，为 最先进的 B0 垫片技术在临床上得到广泛使用，并真正实现从实验室到床边的转变。