REAL-TIME INTERACTIVE MR VASCULAR IMAGING

我们建议开发一种实时交互磁共振仪系统。 Nance(MR)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 假设这种方法及其变种可以被开发来提供 一种快速评估血管形态和功能的有效方法 定量的流量信息。将在三个方面开展工作： 1.图像采集物理。我们将研究三种普遍的方法，全部 利用相位差速度估计。短tr梯度回波脉冲 将开发用于高空间分辨率成像的序列 图像速率为1赫兹的时间平均流量。回声平面方法将是 开发用于提供5-10赫兹的图像速率。行扫描技术将 可在25-50赫兹范围内实现时间分辨率。理论上， 模拟，并将进行实验，以关联 将血管信号重建为实际的血流速度波形 体积流率。灵敏度、分辨率、准确度和 精确度将被确定。 2.高速仪器。我们将设计工具来支持 使用上述任何技术获取的数据的即时重建- 小甜饼。彩色速度贴图将叠加在震级图像上 实时费率。将开发互动技术，以促进 调整扫描参数，例如图像平面角度， 影响图像质量。定量流量数据将在25赫兹确定 实时费率。 3.在活体评估中。这些技术将在评估中进行评估- 正常志愿者上腹部血管血流的变化。 我们相信，这项工作将导致第一个实时交互的MR 血管成像系统，以及我们以前的实时体验 收购和重建独一无二地使我们有资格进行这些 学习。

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.