Long Field Of View MRA Using Continuous Table Motion

该项目的长期目标仍然是开发能够进行磁共振数据采集的方法 在患者床面持续运动期间进行增强磁共振血管成像研究 外周血管系统。这将允许来自腹部的血管系统的诊断质量成像和 骨盆到足部，以便诊断和表征外周血管疾病。在连续成像过程中 工作台运动允许高效率地使用扫描时间和对比剂剂量。因为一个给定的 轴向水平在移动视野内仅在有限的时间内成像，通常为20秒或更短 这对于在给定的采集时间内提高空间分辨率至关重要。为此，加速技术 在01-04年度展示的一维将延伸到两个横向维度。另一个 该研究的主要目的是实时成像对比剂剂量传递，自动跟踪其位置，并使用 此信息可自动调整工作台速度。奖助金申请包括以下具体内容 目标： 1.采用2D加速技术对固定视场进行高分辨率CE-MRA。在为成像做准备时 在连续的工作台运动期间，将首先开发用于执行高度加速的采集的技术 在目标20秒内无工作台运动期间。椭圆中心视图顺序将与2D相结合 零差、二维感和时间分辨视图共享获取。 2.在连续工作台运动过程中应用的并行捕获技术。加速收购 Aim#1的方法将适用于连续移动的台面成像。重建算法将是 开发了用于渐变翘曲、2D感测和可变视场获取的工具。将开发线圈 这允许在扩展的视场上进行高效的2D并行采集。 3.连续移床外周MRA的患者特异性采集。方法将被开发为 当造影剂沿周围血管系统移动时，检测造影剂的前沿，然后使用此 实时改变患者床位运动的信息。将开发针对患者的推注配置文件，其中包括 测试推注，然后与全对比推注一起使用，以驱动高空间分辨率诊断质量的采集。 最终，这一过程将仅使用完全对比剂进行。

The long term objective of this project continues to be the development of methods which permit MR data acquisition during continuous motion of the patient table for contrast-enhanced MR angiographic studies of the peripheral vasculature. This will allow diagnostic quality imaging of the vasculature from the abdomen and pelvis to the feet to allow diagnosis and characterization of peripheral vascular disease. Imaging during continuous table motion permits high efficiency in the use of scan time and of the contrast dose. Because a given axial level is imaged within the moving field-of-view for only a limited time, typically 20 seconds or less, it is critical to allow improvements in spatial resolution for a given acquisition time. To this end, acceleration techniques demonstrated in Years 01-04 in one dimension will be extended to the two lateral dimensions. Another major aim of the study is to image the contrast dose transit in real time, automatically track its position, and use this information to automatically adjust the table velocity. The grant application includes the following specific aims: 1. High Resolution CE-MRA of a Fixed FOV Using 2D Acceleration Techniques. In preparation for imaging during continuous table motion, techniques will first be developed for performing highly accelerated acquisitions during no table motion within a targeted 20 sec. The elliptical centric view order will be combined with 2D homodyne, 2D SENSE, and time-resolved view-shared acquisition. 2. Parallel Acquisition Techniques Applied During Continuous Table Motion. The accelerated acquisition methods of Aim #1 will be adapted to continuously moving table imaging. Reconstruction algorithms will be developed which account for gradient warping, 2D SENSE, and variable FOV acquisition. Coils will be developed which allow efficient 2D parallel acquisition over an extended FOV. 3. Patient-Specific Acquisition for Continuously Moving Table Peripheral MRA. Methods will be developed to detect the leading edge of the contrast bolus as it moves along the peripheral vasculature and then to use this information to alter the patient table motion in real time. A patient-specific bolus profile will be developed with a test bolus and then used with the full contrast bolus to drive the high spatial resolution diagnostic-quality acquisition. Eventually this process will be performed using the full contrast bolus alone.