REAL-TIME INTERACTIVE MR VASCULAR IMAGING

我们建议开发一个实时交互式磁共振成像系统。 磁共振血管成像。 要开发的主要技术是 实时交互式彩色血流相位差成像。 我们 假设该方法及其变体可以被开发以提供 快速评估血管形态的有效方法， 定量流量信息。 将在三个领域开展工作： 1.图像采集物理学。 将研究三种一般方法， 相位差速度估计。 短TR梯度回波脉冲 序列将被开发用于高空间分辨率成像， 图像速率为1 Hz时的时间平均流量。 回波平面方法将是 开发提供5-10 Hz的图像速率。 行扫描技术将 在25-50赫兹范围内的时间分辨率。 理论上， 模拟和实验将进行相关的 将重建的血管信号转换为实际的血流速度波形， 体积流率 灵敏度、分辨率、准确度和 精度将被确定。 2.高速仪表。 仪器的设计将使 使用上述任何技术获取的数据的即时重建 尼克。 彩色速度图将覆盖在幅度图像上， 实时利率。 将开发互动技术， 扫描参数的调整，如图像平面角度， 影响图像质量。 将在25 Hz下确定定量流量数据 真实的利率。 3.体内评估。 这些技术将在评估中进行评估- 正常志愿者上腹部的血管血流图。 我们相信，这项工作将导致第一个实时交互式MR 血管成像系统，我们以前的经验，在实时 收购和重建使我们有资格进行这些 问题研究

We propose to develop a system for real-time interactive magnetic reso- nance (MR) vascular imaging. The principal technique to be developed is real-time interactive color flow phase difference imaging. We hypothesize that this method and its variants can be developed to provide an efficient method for rapid assessment of vascular morphology and quantitative flow information. Work will be done in three areas: 1. Image Acquisition Physics. Three general methods will be studied, all with phase difference velocity estimation. Short TR gradient echo pulse sequences will be developed for high spatial resolution imaging of time-averaged flow at image rates of 1 Hz. Echo-planar methods will be developed to provide image rates of 5-10 Hz. Line scan techniques will be developed for temporal resolution in the 25-50 Hz range. Theory, simulations, and experiments will be performed to relate the reconstructed vascular signal to the actual blood velocity waveform and volume flow rate. Limits of sensitivity, resolution, accuracy, and precision will be determined. 2. High Speed Instrumentation. Instrumentation will be devised to enable instant reconstruction of data acquired using any of the above tech- niques. Color velocity maps will be overlaid on magnitude images at real-time rates. Interactive techniques will be developed to facilitate adjustment of scan parameters, such as image plane angulation, which affect image quality. Quantitative flow data will be determined at 25 Hz rates in real time. 3. In Vivo Assessment. The techniques will be evaluated in the assess- ment of vascular flow in the upper abdomen of normal volunteers. We believe that this work will lead to the first real-time interactive MR vascular imaging system, and that our previous experience in real-time acquisition and reconstruction uniquely qualifies us to conduct these studies.