MRI ASSESSMENT OF EXPERIMENTALLY INDUCED TRAUMATIC BRAIN INJURY IN RATS

实验性大鼠脑外伤的 MRI 评估

• 批准号: 6669260
• 负责人: PATRICK KOCHANEK
• 金额: $ 13.47万
• 依托单位: CARNEGIE-MELLON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-30 至 2003-08-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6669260
• 关键词: bioengineering /biomedical engineering; bioimaging /biomedical imaging; biomedical equipment development; biomedical resource; cardiovascular system; magnetic resonance imaging; statistics /biometry; technology /technique

The objective of this project is to develop ultra-fast magnetic resonance imaging techniques and applying them to measuring flow and motion. This is accomplished by: (i) developing ultra-fast imaging for assessment of simple linear (i.e., one directional) flow; (ii) developing ultra-fast imaging for application and assessment of more complex and other rapidly-varying phenomena; (iii) applying ultra-fast imaging techniques developed for Specific Aims (i) and (ii) to the analysis of in-vivo flow and other dynamic in-vivo phenomena, such as heart motion. Rotating Ultra-Fast Imaging Sequence (RUFIS) developed in this Center uses free induction decays (FID) for image reconstruction, and usually the data points at the begining of the FID are not available because of finite recovery times of the hardware. We improved image reconstruction by substituting a Linear Algebra Method (LAM) to reconstruct image profiles directly from FID data. Simulations confirm that the LAM method can accurately reconstruct 1 D projections from oversampled data even when 1/4 of k-space is missing or noise is present. Simulations were also performed to examine and confirm the minimal effects of turbulence and diffusion on signal loss. Using a spin echo-based velocity-encoding preparation sequence followed by RUFIS, quantitative velocity profiles of laminarand turbulent flow have been obtained. Flow has been quantified inside a straightglass phantom, emerging from a stenosis, and traveling through a curved channel. We also used RUFIS to analyze flow boundary reattachment and the effects of secondary flow patterns in curved flow. We also began to adapt RUFIS sequences for in vivo imaging of the rat. RUFIS can be used as an accurate non-invasive technique for distinguishing laminar and turbulent flow, measuring flow velocities, observing eddies, and identifying shear boundary reattachment downstream of a stenosis.

该项目的目的是开发超快速磁 共振成像技术并将其应用于测量流量和 运动。 这是通过以下方式完成的：（i）开发超快速成像 用于评估简单线性（即一个方向性）流的评估； （ii） 开发超快速成像以应用和评估更多 复杂和其他快速变化的现象； （iii）应用超快速 为特定目的（i）和（ii）开发的成像技术 分析体内流动和其他动态体内现象，例如 心脏运动。 旋转的超快速成像序列（RUFIS） 在这个中心，图像使用自由感应衰减（FID） 重建，通常是FID开始的数据点 由于硬件的有限恢复时间，不可用。 我们通过替换线性代数来改善图像重建 方法（LAM）直接从FID数据中重建图像概况。 模拟确认LAM方法可以准确地重建1 D 即使缺少1/4的k-space，超采样数据的预测 或噪音存在。 还进行了模拟以检查和 确认湍流和扩散对信号的影响最小 损失。 使用基于自旋回波的速度编码准备序列 其次是rufis，层层的定量速度曲线 已经获得了湍流。 流量已被量化 富托幻象，从狭窄中浮出水面，然后穿过 弯曲通道。 我们还使用Rufis分析流量边界 弯曲中的次要流动模式的重新计算和效果 流动。 我们还开始适应Rufis序列以进行体内成像 大鼠。 Rufis可以用作准确的非侵入技术 区分层流和湍流，测量流速度， 观察涡流，并识别剪切边界重新安装 狭窄的下游。