HIGH RESOLUTION INTERACTIVE CORONARY ARTERY MRA

描述(改编自申请人摘要)：申请人建议 应用快速磁共振成像脉冲序列和实时信号处理 开发高分辨率磁共振成像技术的技术 冠状动脉。具体的假设是1 mm各向同性 本地冠状动脉树的图像的分辨率可以可靠地 在单次或有限次数的呼吸中在人体内获得。 目前的冠状动脉MRA技术受到以下因素的限制 包括：大量所需的相位编码视图，有限的SNR， 由于心脏和呼吸引起的运动导致的锐度不高，而且有限 血液与背景的对比度。随着决心的加强，这些都变得更加严峻 改进了。申请者建议在 项目：1。心脏磁共振透视。近实时心脏成像 将被用来交互地识别目标冠状动脉血管， 定位所需的倾斜成像平面或平板，并提供即时 切换到高分辨率血管造影术序列。一个或多个这样的 将为三条主要冠状动脉的每一条确定平板， 使每个患者都能形成“选择性”的血管造影术。实时 屏气反馈将提供可重复性和灵活性 屏气；2.高分辨率磁化制备的梯度回声磁共振 血管造影术。反转恢复磁化制备的梯度回波 序列将被改编用于冠状动脉造影成像。将为空 背景心肌将使更小的分支和更远端的血管形成 比用目前的技术更容易被人看到。双斜向采集 将允许显著减少所需的阶段编码数量 因此减少了扫描时间，只允许在几个 屏住呼吸。反转板将量身定做，以避免饱和 动脉血；3.高分辨率多次激发平面回波磁共振 血管造影术。2-D和3-D多激发EPI技术将适用于 冠状动脉造影术。每个心动周期的击球次数、每次观看次数 和梯度力矩归零度将优化为 血管造影成像。预计计划免疫技术将提供更多的 (&gt；3倍)与当前方法相比每单位时间的查看次数，并启用 完整冠状动脉树的单次屏气成像。这个 申请者预计在这个项目中开发的技术可以形成 最终的交互系统的起点是执行许多 心脏影像检查的要素。

DESCRIPTION (Adapted from Applicant's Abstract): The applicants proposed to apply fast MR imaging pulse sequences and real-time signal processing techniques in developing techniques for high resolution MR imaging of the coronary arteries. The specific hypothesis is that 1 mm isotropic resolution of images of the native coronary arterial tree can be reliably obtained in humans during a single or limited number of breathholds. Current techniques for coronary artery MRA are limited from factors which include: a large number of required phase encoding views, limited SNR, unsharpness due to cardiac and respiratory-induced motion, and limited blood-to-background contrast. These all become more severe as resolution is improved. The applicants proposed to address these limitations in the projects of: 1. Cardiac MR Fluoroscopy. Near real-time cardiac imaging will be used to interactively identify the targeted coronary artery vessels, position the desired oblique imaging plane or slab, and provide instant switching to a high resolution angiographic sequence. One or more such slabs will be identified for each of the three major coronary arteries, enabling formation of a "selective" angiogram for each. Real-time breathhold feedback will provide reproducible and yet allow flexible breathholding; 2. High Resolution Magnetization-Prepared Gradient Echo MR Angiography. An inversion recovery magnetization-prepared gradient echo sequence will be adapted for coronary angiographic imaging. Nulling of background myocardium will enable small branches and more distal vasculature to be better seen than with current techniques. Double oblique acquisition will allow considerable reduction of the required number of phase encodings and thus scan time reduction, allowing acquisition over only several breathholds. The inversion slab will be tailored to avoid saturation of arterial blood; and 3. High Resolution Multi-Shot Echo-Planar MR Angiography. 2-D and 3-D multi-shot EPI techniques will be adapted for coronary angiography. The number of shots per cardiac cycle, views per shot, and degree of gradient moment nulling will be optimized for angiographic imaging. EPI techniques are expected to provide an increased (>3X) number of views per unit time compared to current methods and enable single breathhold imaging of a complete coronary artery tree. The applicants projected that the techniques developed in this project can form the starting point for an eventual interactive system for performing many elements of a cardiac imaging examination.