Multi-coil Shimming of the Human Brain at 7 Tesla

7 特斯拉的人脑多线圈匀场

• 批准号: 8431992
• 负责人: ROBIN A DE GRAAF
• 金额: $ 35.3万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-04-01 至 2016-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8431992
• 关键词: Air; Anatomy; Automation; Brain; Brain Diseases; Brain Injuries; Characteristics; Clinical; Communication; Complex; Computer software; Data; Data Quality; Diagnosis; Diffusion; Echo-Planar Imaging; Electromagnetics; Ensure; Functional Magnetic Resonance Imaging; Generations; Gold; Head; Human; Image; Lead; Liquid substance; Magnetic Resonance; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Magnetism; Maps; Measurement; Metabolism; Methods; Modality; Modeling; Morphologic artifacts; Mus; Operative Surgical Procedures; Performance; Predisposition; Problem Solving; Procedures; Protocols documentation; RF coil; Resolution; Shapes; Signal Transduction; Slice; Spatial Distribution; Spectrum Analysis; Stream; Structure; System; Techniques; Tissues; Weight; base; clinical application; flexibility; frontal lobe; human subject; improved; in vivo; innovation; magnetic field; novel; olfactory bulb; operation; quality assurance

DESCRIPTION (provided by applicant): Many magnetic resonance (MR) modalities, like functional MR imaging (MRI), diffusion MRI and MR spectroscopy (MRS) have great potential for the study and diagnosis of brain disease and injury, and guiding surgical therapy. All of these methods benefit greatly from the increased sensitivity, resolution and contrast from high field strength magnets (3T and above). However, the advantages of higher magnetic fields have not been fully realized due to the increasingly confounding effects of magnetic field inhomogeneity caused by magnetic susceptibility differences between air and tissue. Magnetic field inhomogeneity leads to signal loss and spatial distortion in MRI and loss in spectral resolution and sensitivity in MRS. The loss of reliability due to these artifacts is a major reason why these techniques have not seen widespread use in high-field clinical applications. Current methods of magnetic field homogenization based on spherical harmonic shim coils perform well on small volumes but are inadequate to compensate the complex magnetic field distribution across the entire human brain. Here a novel technique based on matrices of DC coils is presented that can achieve superior shimming performance in the human brain in vivo. Preliminary results demonstrate the feasibility of multi-coil (MC) matrix shimming on human brain at 7.0 T. Characterization of the static and temporal characteristics of MC matrices will be established, as well as the integration with RF coils. This application proposes to develop MC matrix shimming to the point where excellent magnetic field homogeneity across the entire human brain at 7 T can be obtained in a robust and automated fashion for use with any existing clinical MR protocol. Specifically, the application is composed of three aims that are focused on optimization of the MC matrix for human brain applications at 7 T (Aim 1), the automation of MC matrix field generation (Aim 2) and demonstration of improved magnetic field homogeneity in a number of MRI, MRS and MRSI applications (Aim 3).

描述（由申请人提供）：许多磁共振（MR）模式，例如功能性MR成像（MRI），扩散MRI和MR光谱法（MRS）（MRS）在研究和诊断脑病和损伤以及指导手术治疗方面具有很大的潜力。所有这些 方法从高磁场强度磁体（3T及以上）的灵敏度，分辨率和对比度提高而受益匪浅。然而，由于磁场不均匀性的越来越混杂的影响，由于空气和组织之间的磁敏感性差异引起的磁场不均匀性，较高磁场的优势尚未完全实现。磁场不均匀性导致MRI的信号丢失和空间失真，以及MRS中光谱分辨率和灵敏度的损失。由于这些技术而导致的可靠性丧失是这些技术在高场临床应用中没有广泛使用的主要原因。基于球形谐波垫圈线圈的当前磁场均匀化方法在小体积上表现良好，但不足以补偿整个人脑的复杂磁场分布。在这里提出了一种基于直流线圈矩阵的新技术，可以在体内实现人脑的出色表现。初步结果表明，将在7.0 t处对人脑上的多线圈（MC）基质的可行性。将建立MC矩阵的静态和时间特征的表征，以及与RF线圈的整合。该应用建议将MC矩阵杂乱无章，以便可以以强大且自动化的方式获得整个人脑的出色磁场同质性，以与任何现有的临床MR协议一起使用。具体而言，该应用由三个目的组成，这些目标旨在在7 t（AIM 1），MC矩阵田间生成（AIM 2）的自动化和在许多MRI，MRS和MRSI应用中的改善磁场同质性（AIM 3）中优化MC矩阵（AIM 1），MC MATRIX的自动化（AIM 2）和改进的磁场同质性（AIM 3）。