O-Space Imaging - Accelerating MRI with Z2 Gradient Encoding

O-Space Imaging - 使用 Z2 梯度编码加速 MRI

• 批准号: 8738660
• 负责人: R Todd Constable
• 金额: $ 48.3万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-30 至 2017-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8738660
• 关键词: Acceleration; Amplifiers; Applications Grants; Area; Back; Clinical; Clinical Research; Complement; Coupling; Data; Development; Elements; Head; Hour; Human; Image; Improve Access; Joints; Lead; Location; Magnetic Resonance Imaging; Methodology; Methods; Morphologic artifacts; Names; Patients; Performance; Phase; Physiologic pulse; Positron-Emission Tomography; Process; Public Health; Relative (related person); Research; Resolution; Sampling; Scanning; Scheme; Shapes; Solutions; Speed; Structure; Surface; Testing; Three-Dimensional Imaging; Time; Work; base; clinical practice; clinically relevant; cost; data acquisition; design; improved; innovation; magnetic field; next generation; novel strategies; public health relevance; radiofrequency; research study; theories; Acceleration; Amplifiers; Applications Grants; Area; Back; Clinical; Clinical Research; Complement; Coupling; Data; Development; Elements; Head; Hour; Human; Image; Improve Access; Joints; Lead; Location; Magnetic Resonance Imaging; Methodology; Methods; Morphologic artifacts; Names; Patients; Performance; Phase; Physiologic pulse; Positron-Emission Tomography; Process; Public Health; Relative (related person); Research; Resolution; Sampling; Scanning; Scheme; Shapes; Solutions; Speed; Structure; Surface; Testing; Three-Dimensional Imaging; Time; Work; base; clinical practice; clinically relevant; cost; data acquisition; design; improved; innovation; magnetic field; next generation; novel strategies; public health relevance; radiofrequency; research study; theories

DESCRIPTION (provided by applicant): Recent improvements in parallel-imaging performance in MRI have been driven by the use of greater numbers of radiofrequency (RF) surface coils placed in an array so as to maximize the ability to unwrap the aliasing that occurs along a linear phase encode direction when the data is undersampled (accelerated). This approach to acceleration is maturing and providing diminishing returns as more and more receiver coils are used, due to coil-coupling problems, which dominate as the size of the coil elements decreases and the number of elements increases. This proposal is aimed at providing further acceleration in parallel imaging through a reassessment of the magnetic field gradients used for spatial encoding. By considering the joint contributions of spatial encoding of the receiver coils and the magnetic fields, we can develop a more efficient approach to spatial encoding. A simple solution to this problem is to use a nonlinear magnetic field gradient, the Z2 gradient. Such a gradient shape (relative to linear X and Y gradients) provides spatial encoding more complementary to that provided by the receiver coils. The approach we have developed, O-space imaging - so named because the isofrequency contours during the readout are in the shape of concentric rings rather than columns as with a linear X-readout - was initially introduced by us in 2010. The theory and preliminary data generated using a small Z2-gradient insert on a clinical MRI scanner have provided evidence that substantial increases in acceleration can be achieved with modest numbers of receiver coils. This proposal is aimed at scaling these tests up to human imaging levels using a head-insert Z2-gradient coil fully integrated with the Siemens 3T Trio scanner. The O-space imaging approach is a general acceleration method that can be adapted to almost any pulse sequence. We will test, in phantom and human imaging experiments, the capabilities of O-space imaging to outperform conventional SENSE imaging using modified spin echo, fast spin echo and 3D imaging sequences at a range of resolutions and acceleration factors and using both an 8-channel and a 32-channel Tx/Rx coil. The end result of this work will be a demonstration of the viability of this new methodology for providing highly accelerated parallel imaging. The project is highly innovative and by reconsidering the spatial encoding gradients it opens up a new area of research in MR accelerated imaging. The project is significant in that providing an acceleration factor of 2 or more to a number of standard clinical MR pulse sequences could provide a huge benefit to public health, allowing for higher resolution, or more detailed examinations, and significantly increased throughput improving access to MRI and/or lowering per-scan costs.

描述（由申请人提供）：MRI中并行成像性能的最新改进是由放置在阵列中的大量辐射射频（RF）表面线圈的使用，以最大程度地提高沿线性相位编码时沿线性相位编码的异叠的能力（加速采样）。这种加速方法正在成熟并提供降低的回报，因为线圈耦合问题越来越多，随着线圈耦合问题的使用，随着线圈元件的大小减小，元素数量的增加而占主导地位。该建议旨在通过重新评估用于空间编码的磁场梯度来提供并行成像的进一步加速。通过考虑接收器线圈和磁场的空间编码的关节贡献，我们可以开发出更有效的空间编码方法。解决此问题的一个简单解决方案是使用非线性磁场梯度Z2梯度。这种梯度形状（相对于线性X和Y梯度）提供了与接收器线圈提供的更互补的空间编码。我们开发的方法，o空间成像 - 之所以命名，是因为我们最初在2010年由我们引入了同心环而不是列的同心环而不是列的形状。该提案旨在使用与西门子3T三重奏扫描仪完全集成的头部插入Z2梯度线圈的头部插入Z2级线圈。 O空间成像方法是一种通用加速度方法，可以适应几乎任何脉冲序列。我们将在Phantom和人类成像实验中测试O空间成像的能力，可以在一系列分辨率和加速因子上使用修改后的自旋回波，快速自旋回声和3D成像序列，并使用8个通道和32个通道和32个通道TX/RX COIL。这项工作的最终结果将证明这一点的生存能力 提供高加速并行成像的新方法。该项目具有很高的创新性，并且通过重新考虑空间编码梯度，它为MR加速成像的新研究开辟了新的研究领域。该项目很重要的是，为许多标准的临床MR脉冲序列提供2个或以上的加速系数可以为公共卫生带来巨大的好处，允许更高的分辨率或更详细的检查，并显着增加吞吐量改善对MRI和/或降低人均成本的访问。