Rapid Real-Time MR Angiography of Suspected Stroke

项目概要/摘要： 该项目的目标是开发和验证非常快速和强大的下一代磁 用于患者头颈部血管解剖学和血流动力学评价的磁共振（MR）方案 疑似中风疑似卒中的紧急诊断影像学评价通常涉及非 对比CT检查颅内出血。然而，随后的患者管理是基于 磁共振成像（MRI）提供了更广泛的解剖和功能信息。 MRI方案通常包括解剖成像、弥散加权成像、MR血管造影（MRA） 以检测神经血管系统中的狭窄和闭塞，以及对比增强灌注成像。MRA 是迄今为止这些成像技术中最耗时的（通常需要15分钟或更长的时间用于成像）。 颈部血管和Willis环的联合评价），并且最容易从患者 议案鉴于“时间就是大脑”在中风的紧急评估中，本项目的第一个目标是实现 在不使用造影剂的情况下，神经血管MRA的扫描时间减少五倍或更多，降至<3分钟 代理，同时提高使用运动不敏感成像技术的可靠性。这个项目的另一个目标是 开发一种快速的方案，用于描绘和定量<30 秒我们假设这两个目标可以通过两个协议的发展来实现：1）a 高度加速的非门控静止间隔切片选择（UnQISS）协议利用径向采样， 实时运动检测和同步多切片加速;以及2）高效的半投影电影 动脉自旋标记（ASL）协议，提供高时间分辨率。本项目的最终目标是测试 在一组疑似卒中患者中开发了快速UnQISS和电影ASL方案。预期 该项目的结果是一套快速的协议，用于评估患者的神经血管系统， 疑似中风，迅速通知治疗团队，以指导管理决策， 药物和血管内治疗。由于不涉及造影剂，所开发的方案将是 尤其适用于许多患有慢性肾病的中风患者（1/3）。具体 本项目的目标如下：1.开发和优化快速非增强MRI方案， 提供颅内和颅外血管（主动脉弓至Willis环）的解剖学评估， <3分钟。2.目的：建立一种快速的半投影动脉自旋标记电影技术， 在<30秒内定量颅内血流。3.在疑似中风患者中，为了检验以下假设， 相对于当前使用的MR协议，开发的快速协议提高了图像质量，提供了更多 诊断信息，准确描绘颅内血流模式，并减少扫描时间。

Project Summary/Abstract: The objective of this project is to develop and validate very rapid and robust next-generation magnetic resonance (MR) protocols for anatomic and hemodynamic evaluation of the head and neck vessels in patients with suspected stroke. Emergent diagnostic imaging evaluation of suspected stroke typically involves a non- contrast CT to detect intracranial hemorrhage. However, subsequent patient management is based on the much more extensive anatomical and functional information provided by magnetic resonance imaging (MRI). The MRI protocol typically consists of anatomic imaging, diffusion-weighted imaging, MR angiography (MRA) to detect stenosis and occlusion in the neurovascular system, and contrast-enhanced perfusion imaging. MRA is by far the most time-consuming of these imaging techniques (typically requiring 15 minutes or longer for the combined evaluation of the neck vessels and circle of Willis), and the most prone to degradation from patient motion. Given that “time is brain” in the emergent evaluation of stroke, the first goal of this project is to achieve a five-fold or greater decrease in scan time for neurovascular MRA to <3 minutes without the use of contrast agents, while improving reliability using motion-insensitive imaging techniques. Another goal of this project is to develop a rapid protocol for portraying and quantifying intracranial flow patterns and velocities in <30 seconds. We hypothesize that these two goals can be met through the development of two protocols: 1) a highly-accelerated ungated quiescent-interval slice-selective (UnQISS) protocol leveraging radial sampling, real-time motion detection, and simultaneous multi-slice acceleration; and 2) an efficient semi-projective cine arterial spin-labeled (ASL) protocol providing high temporal resolution. A final goal of this project is to test the developed rapid UnQISS and cine ASL protocols in a group of patients with suspected stroke. The expected outcome of this project is a set of rapid protocols for evaluating the neurovascular system in patients with suspected stroke that expeditiously informs the treatment team to guide management decisions regarding medical and endovascular therapy. Since no contrast agents are involved, the developed protocols will be especially useful in the many stroke patients (1 in 3) who present with chronic kidney disease. The specific aims of this project are as follows: 1. To develop and optimize a rapid nonenhanced MRI protocol that provides for anatomical assessment of the intracranial and extracranial vessels (aortic arch to circle of Willis) in <3 minutes. 2. To develop a rapid semi-projective arterial spin-labeling cine technique for displaying and quantifying intracranial flow in <30 sec. 3. In suspected stroke patients, to test the hypotheses that the developed rapid protocols, with respect to currently-used MR protocols, improve image quality, provide more diagnostic information, accurately portray intracranial flow patterns, and decrease scan times.