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: 10891767
• 负责人: Christoph Juchem
• 金额: $ 8.74万
• 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 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10891767
• 关键词: Area; Automobile Driving; Brain; Brain imaging; Clinical; Complex; Computer-Aided Design; Coupling; Cranial Nerves; Cranial nerve diseases; Dedications; 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; Visualization; bench-to-bedside translation; brain magnetic resonance imaging; brain tissue; clinical diagnostics; clinical imaging; cognitive function; design; diagnostic value; 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.

项目总结 快速梯度回波MRI是显示人脑组织铁沉积的首选方法 磁化率加权成像(SWI)，用回波平面成像(EPI)标测功能活动并评估 脑神经疾病的稳态自由进动(SSFP)磁共振成像。然而，它对 B0磁场的不均匀性带来了严峻的挑战。特别强烈和局部化的B0偏差是 在前额叶皮质(PFC)的窦腔上方观察，这是一个涉及到更高级别的大脑区域 认知功能，以及由眼睛和脑神经等组成的轨道。空间影像 非均匀B0条件引起的变形和信号丢失严重限制了梯度回波磁共振成像 质量，甚至使结果毫无用处，从而从根本上限制其诊断潜力。我们有 最近在整个大脑获得高水平B0同质性的能力方面取得了重大进展， 包括难以填补的领域，例如使用新型多线圈硬件与快速B0相结合的PFC 优化方法和动态垫片。采用这种动态多线圈技术的B0垫片 (炸药)提供比标准方法更好的B0同质性，并且在未来应该 几乎完全消除了B0不均匀性这一问题。我们在这项提议中的目标是将 炸药B0垫片与临床射频技术建立第一个集成的多线圈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产生炸药B0填充场的潜力 通过驱动RF相控的元件，将专用多线圈B0设置与所使用的RF线圈分开 考虑电磁耦合的混合方法中具有DC电流或其组合的阵列 和安全。具体目标2：计算机辅助设计(CAD)方法，包括电磁、热学和 利用力学模型实现临床3T磁共振扫描仪的MC/RF星座优化 环境，以高效、可靠和安全的方式提供核磁共振诊断能力。此外， 根据常规临床MRI方案量身定做的Dynamite B0垫片有望改善整体图像 与传统的基于球谐的B0垫片技术相比，整个人脑的质量。 具体目标3：将炸药B0垫片应用于视神经疾病的诊断成像 以全自动方式对医务人员透明的常规协议和工作流程，以测试 假说增强的诊断潜力和真正的临床好处，由于核磁共振伪影缓解。这个 方法是创新的，因为最好的B0垫片和射频技术相结合，以提供 前所未有的临床核磁共振能力。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和眼眶的诊断潜力，为 临床上广泛使用最先进的B0垫片技术，真正实现了从板凳到床边的转换。