Discovery and Applied Research for Technological Innovations to ImproveHuman Health

改善人类健康的技术创新的发现和应用研究

• 批准号: 10841979
• 负责人: William A Grissom
• 金额: $ 37.41万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10841979
• 关键词: 3-Dimensional; Address; Algorithms; Amplifiers; Applied Research; Brain imaging; Clinical; Data; Development; Dimensions; Frequencies; Generations; Goals; Health; Heating; Human; Image; Individual; Intuition; Length; Location; Loudness; MRI Scans; Magnetic Resonance Imaging; Magnetism; Maps; Methods; Noise; Patients; Performance; Peripheral Nerve Stimulation; Phase; Physiologic pulse; Process; Protocols documentation; Rotation; Safety; Scanning; Signal Transduction; Slice; System; Techniques; Technology; Three-Dimensional Imaging; Tissues; Translating; Translations; Visit; Work; commercialization; compliance behavior; contrast imaging; cost; human imaging; image reconstruction; imaging modality; imaging system; improved; in vivo; in vivo imaging; innovation; magnetic field; neuroimaging; portability; pre-clinical; radio frequency; reconstruction; success; technological innovation; transmission process

Project Summary The goal of this project is to translate RF encoding methods developed in an R21 project to human imaging, by implementing them on a very low field human MRI scanner. Its successful completion will enable silent, low-cost and more portable MRI systems, leading to a substantial reduction in the cost of imaging and improved patient compliance and comfort. In conventional MRI, a received signal is localized to its spatial location of origin based on its temporal frequency, which is controlled using magnetic fields that are parallel to the main (B0) field of the scanner and vary linearly across space. There are many problems with these B0 gradient fields: they are loud and induce peripheral nerve stimulation, compromising patient comfort; they have relatively long switching times due to the high inductance of the coils; they require bulky cooling systems and customized amplifiers; and they are expen- sive, representing 25-30% of the cost of a clinical scanner. B0 gradient encoding also suffers from spatial errors due to concomitant terms, which increase with decreasing B0 field strength and will limit the performance of emerging portable and low-cost MRI systems. A potential solution to these problems is to replace B0 gradients with RF gradients, which are silent and low-cost. Unfortunately, in spite of its potential RF gradient encoding has not yet become a clinical or commercial success. This is largely due to the fact that no existing RF gradient encoding method offers the orthogonality between contrast development and spatial encoding that is enjoyed by B0 gradients, or a straightforward path to convert existing B0 gradient-based MRI scans to use RF encoding. The methods developed in this project are the first to meet these requirements, and will thus be the first truly viable RF gradient-based imaging methods. The central innovation of this project is to use the Bloch-Siegert (BS) shift to spatially encode the MRI signal. As with B0 gradients, this encoding mechanism is based on the application of phase shifts to magnetization directly in the transverse plane, and therefore does not modulate the magnitude of the transverse magnetization, leaving image contrast unaffected by spatial encoding. The first Aim of the project is to develop array and solenoid RF gradient coils and associated RF hardware to enable 2D and 3D Cartesian brain imaging on a human 0.0475 Tesla MRI scanner, including strategies for simultaneous RF transmission and reception to enable frequency encoding by BS shift. The second Aim is to develop and implement RF-encoded pulse sequences for brain imaging based on the BS shift, leveraging key developments from the R21 phase of the project including swept RF pulses for phase encoding, a theoretical basis and pulse sequence for BS frequency encoding, and RF pulses for RF gradient-based slice-selective excitation and slice-encoding. The third Aim is to develop image reconstructions and evaluate the encoding methods in human brain imaging. Successful completion of these Aims will establish the first viable fully RF-encoded human imaging system and pave the way for commercialization and clinical use.

项目概要 该项目的目标是将 R21 项目中开发的射频编码方法转化为人类成像，方法是 在极低场人体核磁共振扫描仪上实施它们，其成功完成将实现安静、低成本。 和更便携式的 MRI 系统，从而大幅降低成像成本并改善患者的病情 合规性和舒适性。 在传统 MRI 中，接收到的信号根据其时间定位到其起源的空间位置。 频率，使用与扫描仪主 (B0) 场平行的磁场进行控制， 这些 B0 梯度场存在许多问题：它们声音很大并且会产生感应。 周围神经刺激，影响患者舒适度； 线圈的高电感；它们需要庞大的冷却系统和定制的放大器； 占临床扫描仪成本 25-30% 的 B0 梯度编码也存在空间误差。 由于伴随项，其随着 B0 场强的降低而增加，并将限制性能 新兴的便携式低成本 MRI 系统的一个潜在解决方案是取代 B0 梯度。 不幸的是，尽管它具有潜在的射频梯度编码功能，但它是安静且低成本的。 尚未在临床或商业上取得成功，这主要是由于没有现有的射频梯度。 编码方法提供了对比度发展和空间编码之间的正交性，这是 B0 梯度，或将现有基于 B0 梯度的 MRI 扫描转换为使用 RF 编码的直接路径。 该项目开发的方法是第一个满足这些要求的方法，因此将是第一个真正可行的方法 基于射频梯度的成像方法。 该项目的核心创新是利用 Bloch-Siegert (BS) 位移对 MRI 进行空间编码 与 B0 梯度一样，这种编码机制基于相移对磁化的应用。 直接在横向平面上，因此不会调制横向磁化强度的大小， 使图像对比度不受空间编码的影响 该项目的首要目标是开发阵列和螺线管。 RF 梯度线圈和相关 RF 硬件可实现人体 2D 和 3D 笛卡尔大脑成像 0.0475 Tesla MRI 扫描仪，包括同步射频传输和接收策略以启用频率 第二个目标是开发和实现大脑的射频编码脉冲序列。 基于 BS 偏移的成像，利用该项目 R21 阶段的关键进展，包括扫频射频 相位编码脉冲，BS频率编码的理论基础和脉冲序列，以及RF脉冲 基于 RF 梯度的切片选择性激励和切片编码第三个目标是开发图像重建。 并评估人脑成像的编码方法将成功完成这些目标。 第一个可行的射频编码人体成像系统，为商业化和临床使用铺平了道路。

项目成果

External Dynamic InTerference Estimation and Removal (EDITER) for low field MRI.

用于低场 MRI 的外部动态干扰估计和消除 (EDITER)。

• 发表时间: 2022-02
• 影响因子: 3.3
• 作者: Srinivas, Sai Abitha;Cauley, Stephen F;Stockmann, Jason P;Sappo, Charlotte R;Vaughn, Christopher E;Wald, Lawrence L;Grissom, William A;Cooley, Clarissa Z
• 通讯作者: Cooley, Clarissa Z