HIGH RESOLUTION INTERACTIVE CORONARY ARTERY MRA

描述（改编自申请人的摘要）：申请人提出 进一步开发冠状动脉实时交互成像技术 动脉根据上一个供资周期的结果和现状 在该领域中，申请人提出，主要的技术挑战 如今，面对冠状动脉MRA，空间分辨率提高， 技术可靠性，以及需要低于10秒的采集时间。到 为了解决这些问题，申请人提出使用对比材料， 改善了管腔内信号的描绘。更进一步，会发展出一部小说 双翻转角采集方法，当与复杂的 减影，预计允许2D成像的小采集时间， 对沿3D成像的平板方向沿着的对比度的高灵敏度。的 该建议的具体假设是，双翻转角成像可以 用于在成像中提供高对比度的亚毫米空间分辨率 冠状动脉将研究三个项目：1。双翻转角度成像 物理学本申请人提出开发一种技术，其中， 信号可以通过使用在以下条件下采集的数据的复数减法来分离： 不同的翻转角度他们假设这种方法将允许 准确描绘对比增强血管，其直径在 切片选择（Z）方向小于切片厚度。这将是 通过确定最佳翻转角并考虑各种 用于复数减法的装置; 2.实时执行。他们将开发 梯度回波和多次激发EPI序列在低和高之间切换 在连续重复时翻转角度。将执行复数减法 在线，采集和重建适应于允许任意 心动时相;以及3.体内评价。这些技术将在 vivo.他们假设冠状动脉图像是由获得的数据形成的， 使用已知在一些可接受的范围内具有运动的预定义的心脏相位 公差比使用时间固定的 心动阶段确定适合高分辨率的心动时相 成像，将在血管特异性 40 Hz实时将在猪冠状动脉模型中研究该方法。 并与X线血管造影进行比较。

DESCRIPTION (Adapted from Applicant's Abstract): The applicants propose to further develop techniques for real-time interactive imaging of the coronary arteries. Based on results of the previous funding cycle and the current status of the field, the applicants propose that the principal technical challenges facing coronary artery MRA today are improved spatial resolution, improved technical reliability, and the need for sub-10 sec acquisition times. To address these issues, the applicants propose to use contrast material for improved depiction of the intraluminal signal. Further, would develop a novel dual-flip - angle acquisition method which, when combined with complex subtraction, is expected to allow the small acquisition time of 2D imaging and the high sensitivity to contrast along the slab direction of 3D imaging. The specific hypothesis of this proposal is that dual flip angle imaging can be used to provide high contrast sub-mm spatial resolution in imaging of the coronary arteries. Three projects will be studied: 1. Dual Flip Angle Imaging Physics. The applicants propose to develop a technique in which the vascular signal can be isolated by using complex subtraction of data acquired at different flip angles. They hypothesize that this method will allow the accurate depiction of a contrast-enhanced blood vessel whose diameter in the slice-select (Z) direction is smaller than the slice thickness. This will be studied by determination of optimum flip angles and consideration of various means for complex subtraction; 2. Real-Time Implementation. They will develop gradient echo and multi-shot EPI sequences which toggle between low and high flip angles on consecutive repetitions. Complex subtraction will be performed online, and acquisition and reconstruction adapted to allow for arbitrary cardiac phases; and 3. In Vivo Evaluation. The techniques will be studied in vivo. They hypothesize that coronary artery images formed from data obtained using a predefined cardiac phase known to have motion within some acceptable tolerance are less blurred than images obtained using a temporally fixed cardiac phase. To determine the cardiac phase suitable for high resolution imaging, lateral coronary artery motion will be measured on a vessel-specific basis at 40 Hz realtime. The methods will be studied in a pig model of coronary artery stenosis and compared with x-ray angiography.