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.

项目概要/摘要 多线圈 (MC) 匀场阵列已成为一种有前途且灵活的工具，可用于提高 MRI 图像质量。 靠近身体放置的小型独立驱动循环阵列提供了一种有效的方法来生成 快速可切换的磁场偏移 (ΔB0)，可调整形状以提供内部有用的磁场分布 MC 阵列最初被提议用于动态可切换的高空间阶“B0 匀场”。 改进的匀场减少了静态背景 B0 场的主体特定扰动。 平面回波成像中的几何畸变（广泛用于功能性和扩散性 MRI）和线展宽 然而，在过去的几年里，人们提出了 MC 阵列的大量新用途， 包括补充空间编码、改进的脂质抑制、变焦成像和减小翻转角 (B1+) 不均匀性。这种多样化且不断增长的方法——我们将其归类为局部现场控制—— 利用 MC 阵列的两个核心特征：(1) 非正交 ΔB0 基组生成场剖面的能力 不能用线性梯度创建；(2) 能够快速更新匀场电流而不引起 文物。 不幸的是，由于 MC 本地现场控制研究的进展缓慢，超出了少数几个地点。 仪器和控制软件的可用性有限。 开关能力很少见，而那些确实存在的开关能力对于大多数应用来说成本高昂 （>1,000 美元/通道）同时，没有现成的软件可用于控制匀场放大器和 此外，缺乏使用凸面的软件工具。 优化以有效解决匀场电流振幅以实现定制的局部磁场控制我们将进行分解。 通过开发名为 AFFECT（自动化灵活领域）的开源资源，可以消除这些进入壁垒 编码和控制工具包）我们将完善和传播我们之前验证的低成本（100 美元-）。 150/通道），可扩展至 64 通道的低压匀场放大器我们还将升级和封装。 用于处理 B0 场图并计算最佳匀场电流的图形用户界面 (GUI)。 将进行模块化以允许用户插入自己的自定义垫片优化工具最后，我们将创建。 GUI 和扫描仪主机之间的无缝接口可改善工作流程。 已有 10 多个研究小组联系我们，要求使用我们的开源匀场放大器。 然而，还需要进一步的工作来准备传播的硬件和软件。 该项目旨在将我们的原型转化为强大的、用户可扩展的工具，并进行打包和记录。 为了加快传播，我们将免费为最多 10 个研究小组提供 32 通道放大器设置 用户还可以免费下载原理图并自行制作电路板。