MR FLUOROSCOPY TRIGGERING FOR HIGH RESOLUTION MRA

描述（改编自申请人摘要）：研究人员建议 应用磁共振成像（MRI）技术， 上一个资助周期的这一赠款磁共振血管造影成像。 的 待检验的特定假设是高分辨率动脉相 没有运动伪影的血管造影片可以可靠地采集， 血管区域（肾、颈动脉、主动脉、肺）使用静脉内 造影剂给药。 尽管人们对三维增强MR的兴趣越来越大， 血管造影术受到主要物理现象的限制，包括： 定时，不需要的静脉信号污染，有限的空间 分辨率，以及在胸部和腹部区域中的运动伪影。 这些都影响了整体的可靠性。 研究人员建议 联合收割机处理这些问题：（一）椭圆圆心 视图顺序，和（ii）实时MR荧光透视。 随着最终产品 操作员将使用实时MR监测目标血管区域 荧光透视检查和检测到造影剂后立即触发 具有最佳高分辨率动脉期视图顺序的3D扫描 显像 具体研究项目有：1. 椭圆中心3DFT MR采集。 椭圆视图的基本功能是 区分动脉和静脉阶段将在理论上进行评估， 实验上使用假设的和测量的对比度增强曲线。 TR时间将减少，以提供更高的分辨率; 2. MR透视 触发 成像序列和硬件将被开发用于实时 监测目标脉管系统近端的造影剂， 高分辨率3DFT序列。 将开发用于瞬时 开始三维扫描 非均匀部分k空间更新 将进行采样以提高时间分辨率。 装置将 进行研究，以便于定位透视平面; 和3. 系统集成和适应目标血管区域。 的 基本技术将适用于特定的解剖区域。 物理 要考虑的参数包括快速造影剂通过（特别是在 肺成像），所有三维的精细分辨率（颈动脉， 肾）、扩展视野（肺、主动脉）和多个颞叶 框架（肾脏）。

DESCRIPTION (Adapted from Applicant's Abstract): The investigators propose to apply magnetic resonance imaging (MRI) techniques developed in the previous funding cycle of this grant to MR angiography imaging. The specific hypothesis to be tested is that high resolution arterial phase angiograms devoid of motion artifact can be reliably acquired in major vascular regions (renal, carotid, aorta, pulmonary) using intravenous contrast administration. Despite growing interest, 3-D contrast enhanced MR angiography is limited by major physical phenomena including: Uncertainties of timing, contamination by unwanted venous signal, limited spatial resolution, and, in the thoracic and abdominal regions, motion artifact. These all affect the overall reliability. The investigators propose to combine two methods to deal with these problems: (I) an elliptical centric view order, and (ii) real-time MR fluoroscopy. With the end product an operator will monitor the targeted vascular area with real-time MR Fluoroscopy and upon detection of contrast material immediately trigger a 3-D scan with a view order optimum for high resolution arterial phase imaging. Specific projects to be studied are: 1. Elliptical Centric 3DFT MR Acquisition. The fundamental ability of the elliptical view order to distinguish arterial and venous phases will be assessed theoretically and experimentally using hypothetical and measured contrast enhancement curves. TR times will be reduced to provide improved resolution; 2. MR Fluoroscopic Triggering. Imaging sequences and hardware will be developed for real-time monitoring of contrast material proximal to the targeted vasculature for the high resolution 3DFT sequence. Means will be developed for instantaneous initiation of the 3-D scan. Partial k-space updating with nonuniform sampling will be implemented for improved temporal resolution. Means will be studied to facilitate positioning of the fluoroscopic plane of section; and 3. System integration and adaptation to targeted vascular areas. The basic technique will be adapted to specific anatomic areas. Physical parameters to be accounted for include fast contrast passage (especially in pulmonary imaging), fine resolution in all three dimensions (carotid, renal), extended field of view (pulmonary, aorta) and multiple temporal frames (renal).