Open-source software and hardware tools for local B0 field control

用于本地B0现场控制的开源软件和硬件工具

• 批准号: 10019546
• 负责人: Jason P Stockmann
• 金额: $ 34.39万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-20 至 2022-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10019546
• 关键词: Adoption; Affect; Amplifiers; Area; Brain; Charge; Communities; Computer software; Computers; Coupling; Custom; Data; Diffusion; Diffusion Magnetic Resonance Imaging; Echo-Planar Imaging; Expedite Dissemination; Feedback; Financial compensation; Goals; Hand; Image; Joints; Least-Squares Analysis; Lipids; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Malignant Neoplasms; Maps; Methods; Molecular Profiling; Morphologic artifacts; Noise; Output; Physiologic pulse; Plug-in; Predisposition; Process; Productivity; Protocols documentation; Publishing; Research; Research Personnel; Resource Sharing; Resources; Scanning; Signal Transduction; Site; Slice; Software Tools; Specific qualifier value; Structure; Time; Tissues; Translating; Update; Work; anxious; contrast imaging; cost; design; digital; experimental study; flexibility; graphical user interface; improved; in vivo; instrumentation; interest; magnetic field; open source; physical separation; prevent; programs; prototype; scale up; simulation software; soft tissue; software development; tool; tumor; usability; user-friendly; voltage; web site

Project Summary/Abstract Multi-coil (MC) shim arrays have emerged as a promising and flexible tool for improving MRI image quality. Arrays of small, independently-driven loops placed close to the body provide an efficient way to generate rapidly-switchable magnetic field offsets (ΔB0) that can be shaped to provide useful field profiles inside the body. MC arrays were originally proposed for dynamically-switchable, high spatial order “B0 shimming” in the body to null subject-specific perturbations of the static background B0 field. The improved shimming reduces geometric distortion in echo planar imaging (widely used for functional and diffusion MRI) and line broadening in MR spectroscopy. However, in the past few years, a surge of new uses for MC arrays have been proposed, including supplementary spatial encoding, improved lipid suppression, zoomed imaging, and reduced flip angle (B1+) inhomogeneity. This diverse and growing set of methods – which we classify as local field control – exploit two core features of MC arrays: (1) the ability of non-orthogonal ΔB0 basis sets to generate field profiles that can not be created with linear gradients; and (2) the ability to rapidly update shim currents without causing artifacts. Unfortunately, MC local field control research has been slow to spread beyond a small handful of sites due to limited availability of instrumentation as well as control software. Commercial shim amplifiers with dynamic switching capability are rare, and those that do exist are cost-prohibitive for most applications (>$1,000/channel). At the same time, there is no readily-available software for controlling shim amplifiers and interfacing with the scanner host computer. Moreover, there is a lack of software tools using convex optimization to efficiently solve for shim current amplitudes for tailored local field control. We will break down these barriers to entry by developing an open-source resource called AFFECT (Automated Flexible Field Encoding and Control Toolkit). We will refine and disseminate our previously-validated low-cost ($100- 150/channel), low-voltage shim amplifier that is scalable up to 64-channels. We will also upgrade and package a graphical-user-interface (GUI) used to process B0 field maps and compute optimal shim currents. The GUI will be made modular to allow users to plug in their own custom shim optimization tools. Finally, we will create a seamless interface between the GUI and the scanner host computer to improve workflow. More than 10 research groups have already contacted us asking to use our open-source shim amplifiers. However, further work is required to prepare both the hardware and software for dissemination. The goal of this project is to translate our prototypes into robust, user-extensible tools that are packaged and documented. To expedite dissemination, we will provide up to 10 research groups with 32-channel amplifier setups free of charge. Users will also be free to download schematics and fabricate the circuit boards on their own.

项目摘要/摘要 多线圈（MC）垫片阵列已成为提高MRI图像质量的承诺和灵活的工具。 靠近身体的小型，独立驱动的环数组提供了一种有效的生成方式 可快速切换的磁场偏移量（ΔB0）可以形成以提供有用的场曲线 身体。 MC阵列最初是针对动态切换的高空间秩序“ B0 Shimming”提出的 静态背景B0场的主体特定主体特异性扰动。改进的光滑降低 回声平面成像中的几何畸变（广泛用于功能和扩散MRI）和线扩展 在MR光谱法中。但是，在过去的几年中，已经提出了大量的MC阵列用途， 包括补充空间编码，改进的脂质抑制作用，缩放成像和翻转角度降低 （B1+）不均匀性。我们将其归类为本地现场控制的潜水员和不断增长的方法 - 利用MC数组的两个核心特征：（1）非正交ΔB0基集生成场剖面的能力 不能用线性梯度创建。 （2）能够快速更新垫片电流而不会引起的能力 文物。 不幸的是，MC本地野外控制研究的速度很慢，无法超越少数网站。 有限的仪器可用性以及控制软件。具有动态的商业垫片放大器 切换功能很少，并且确实存在的功能对于大多数应用来说都是成本良好的 （> $ 1,000/频道）。同时，没有用于控制垫片放大器和 与扫描仪主机计算机接口。此外，缺乏使用凸的软件工具 优化以有效求解垫片电流放大器的量身定制的局部场控制。我们会崩溃 通过开发一种称为Affem的开源资源（自动化灵活领域）来进入这些障碍 编码和控制工具包。我们将完善并传播我们先前验证的低成本（$ 100- 150/通道），低压垫片放大器，可扩展高达64通道。我们还将升级和包装 用于处理B0场图和计算最佳垫片电流的图形用户接口（GUI）。 GUI 将使模块化使用户插入自己的自定义垫片优化工具。最后，我们将创建 GUI和扫描仪主机计算机之间的无缝接口以改善工作流程。 超过10个研究小组已经与我们联系，要求使用我们的开源垫片放大器。 但是，需要进一步的工作来准备硬件和软件以进行传播。目标 该项目是将我们的原型转换为包装和记录的可靠，可扩展的工具。 为了加快传播，我们将提供最多10个研究小组，并提供32个通道放大器设置 收费。用户还可以自由下载计划并自己制造电路板。