MAGNETIC RESONANCE FLUOROSCOPY TRIGGERING FOR HIGH RESOL

高分辨率磁共振透视触发

• 批准号: 6694407
• 负责人: Stephen J Riederer
• 金额: $ 28.54万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 1984
• 资助国家: 美国
• 起止时间: 1984-08-01 至 2005-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6694407
• 关键词: angiography; bioimaging /biomedical imaging; biomedical equipment; biomedical equipment development; clinical biomedical equipment; clinical research; computer data analysis; contrast media; diagnosis design /evaluation; fluoroscopy; human subject; image enhancement; image processing; magnetic resonance imaging; method development

We propose to further develop real-time magnetic resonance imaging (MRI) techniques developed in the previous funding cycle toward high resolution MR angiographic imaging. The specific hypothesis is that compared to the current performance level of fluoroscopically-triggered elliptical-centric contrast-enhanced 3D MRA 30 percent improved spatial resolution and 40 percent improved signal can be obtained in imaging many vascular areas. Despite increased interest, contrast-enhanced MRA continues to be limited by spatial resolution. In the previous funding cycle we developed the technique of fluoroscopically-triggered contrast- enhanced MRA and showed that it can reliably provide high spatial resolution, venous-suppressed angiograms in virtually all arterial areas from the carotid bifurcation to the pelvis (with the exception of the coronary arteries). We have also theoretically determined the dependence of spatial resolution in 3D CE-MRA on MR acquisition parameters and contrast bolus characteristics. We wish to further apply this real-time MRI capability, clinical experience, and theoretical development to generate images with an improved level of resolution and signal. Specific projects to be studied are: 1. k-Space Signal Enhancement Methods. The general strategy for resolution improvement is to obtain increased signal level at the peripheral k-space views. This will be done by TR reduction, FOV reduction, prolongation of the contrast bolus, and selection of scan time. 2. Real-Time MRA Sequence Modification. In order to exploit the risetime of the arriving contrast bolus, a centric-in portion of the MRA acquisition will precede the standard elliptical centric- (out) sequence. The characteristics of the view order will be modified in real time in response to the instantaneously measured bolus transit time. The flip angle of the readout will be altered dynamically to match the time-dependent Ernst angle. 3. Embedded Fluoroscopic/3D MRA. Repetition intervals devoted to 2D fluoroscopic imaging will be inserted into the elliptical centric 3D MRA sequence. These will be sorted, reconstructed and displayed during the 3D acquisition allowing he operator to observe contrast behavior and intervene, such as by triggering another temporal frame or advancing the table.

我们建议进一步发展实时磁共振成像（MRI）技术，该技术在上一个资金周期中开发，以实现高分辨率MR血管造影成像。 具体的假设是，与目前的荧光透视触发椭圆中心对比增强3D MRA的性能水平相比，在许多血管区域成像中可以获得30%的空间分辨率提高和40%的信号改善。尽管人们对增强MRA的兴趣越来越大，但它仍然受到空间分辨率的限制。 在上一个资助周期中，我们开发了荧光透视触发对比增强MRA技术，并表明它可以可靠地提供从颈动脉分叉到骨盆的几乎所有动脉区域（冠状动脉除外）的高空间分辨率静脉抑制血管造影。 我们还从理论上确定了3D CE-MRA的空间分辨率对MR采集参数和对比剂团特征的依赖性。 我们希望进一步应用这种实时MRI能力、临床经验和理论发展来生成具有改进的分辨率和信号水平的图像。具体研究项目有：1. k空间信号增强方法 提高分辨率的一般策略是在外围k空间视图处获得增加的信号水平。 这将通过TR减小、FOV减小、造影剂团注时间延长和扫描时间选择来完成。2.实时MRA序列修改。 为了利用到达造影剂团的上升时间，MRA采集的中心入部分将先于标准椭圆中心出序列。 视图顺序的特性将响应于即时测量的团通过时间而在真实的时间中被修改。 读出的翻转角将被动态地改变以匹配时间相关的恩斯特角。 3.嵌入式透视/3D MRA。 将专门用于2D荧光透视成像的重复间隔插入椭圆中心3D MRA序列。 这些将在3D采集期间进行分类、重建和显示，允许操作员观察对比行为并进行干预，例如通过触发另一个时间帧或推进扫描床。