Practical Nonlinear Gradient Encoding for Enhanced Accelerated Imaging

用于增强加速成像的实用非线性梯度编码

• 批准号: 9982310
• 负责人: GIGI GALIANA
• 金额: $ 37.69万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-30 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9982310
• 关键词: 3-Dimensional; Acceleration; Brain; Brain imaging; Calibration; Clinical; Data; Development; Economics; Geometry; Human; Image; Investments; Literature; MRI Scans; Magnetic Resonance Imaging; Methods; Minor; Morphologic artifacts; Motion; Performance; Price; Protocols documentation; Public Health; Resolution; Sampling; Scanning; Signal Transduction; Slice; Techniques; Testing; Time; Vision; base; clinical application; clinical center; clinical research site; contrast imaging; cost; experimental study; improved; in vivo; in vivo imaging; innovation; new technology; reconstruction; simulation; tool

Project Summary/Abstract This project will benefit public health by ushering in a new technology to reduce MRI scan times. FRONSAC adds nonlinear gradients of modest amplitude in dynamic waveforms to standard Cartesian MRI protocols. This small perturbation to the standard Cartesian MRI scan allows for greater undersampling of data, and faster acquisition times. This proposal is innovative because it marries the reliability of Cartesian imaging with a small amount of nonlinear gradient encoding to greatly enhance parallel imaging acceleration. The proposal is significant because it will demonstrate that a single well-characterized nonlinear gradient waveform can improve undersampled imaging for a broad range of clinical sequences and scan prescriptions, potentially doubling overall scan throughput for busy clinical sites. The aims will demonstrate that, for many scan prescriptions, and even in the presence of common experimental imperfections or other parallel imaging strategies, FRONSAC further multiplies acceleration by an additional 2-4x. 1) Sequence development and optimization. a) Develop a FRONSAC waveform, with 3 NLG channels, for a GRE sequence that maximizes clinically acceptable acceleration. b) Using this FRONSAC waveform, develop a set of widely used clinical sequences implementing FRONSAC acceleration: 3D MP-RAGE, bSSFP, TSE and T2w-FLAIR. 2) Demonstrate FRONSAC imaging in vivo. a) Acquire human brain images and compare contrast with conventional encoding. b) Compare undersampling performance between FRONSAC and Cartesian encoding. 3) Show that undersampled images acquired using a FRONSAC gradient optimized for a single geometry shows persistent improvements over Cartesian encoding for human brain imaging (for different geometries and under various common experimental imperfections), and retains compatibility with other acceleration approaches. a) Test for undersampling artifacts when changing FOV, resolution, and slice orientation. b) Test sequences with known (introduced) imperfections: gradient timing errors, imperfect shim, or off-resonance spins. c) Demonstrate compatibility with both kz undersampling and multislice CAIPIRINHA.

项目摘要/摘要 该项目将通过迎接新技术来减少MRI扫描时间来使公共卫生受益。 Fronsac 将动态波形中适度振幅的非线性梯度添加到标准的笛卡尔MRI方案中。 对标准的笛卡尔MRI扫描的这种小扰动允许对数据进行更大的采样，并且 更快的获取时间。该提议具有创新性，因为它与笛卡尔的可靠性结合了 用少量的非线性梯度编码进行成像，以极大地增强平行成像 加速度。该提案很重要，因为它将证明一个符合人才 非线性梯度波形可以改善多种临床范围的无效成像 序列和扫描处方，可能会增加繁忙临床部位的总体扫描吞吐量。 目的将证明，对于许多扫描处方，甚至在有共同的情况下 实验缺陷或其他并行成像策略，Fronsac进一步增加了加速度 另外2-4倍。 1）序列开发和优化。 a）开发具有3个NLG通道的Fronsac波形，以最大化GRE序列 临床上可接受的加速度。 b）使用此Fronsac波形，开发一组广泛使用的临床序列 Fronsac加速度：3D MP-RAGE，BSSFP，TSE和T2W-FLAIR。 2）在体内演示fronsac成像。 a）获取人脑图像并将其与常规编码形成对比。 b）比较Fronsac和笛卡尔编码之间的不足采样性能。 3）证明使用针对单个的fronsac梯度获得的无效图像 几何形状显示了对人脑成像的笛卡尔编码的持续改进（用于 不同的几何形状以及在各种常见的实验缺陷下），并保留 与其他加速方法的兼容性。 a）在更改FOV，分辨率和切片方向时测试无效伪像。 b）具有已知（介绍）缺陷的测试序列：梯度时序误差，不完美的垫片或 异议旋转。 c）表现出与Kz无水采样和多层Caipirinha的兼容性。