Modified Elliptical Centric View Orders for Improved Real-Time MRA

这项工作的广泛，长期的目标是开发新的，时间效率高的方法，磁共振数据 采集和相应的实时信号处理技术， 以高空间分辨率描绘心血管系统。这一点很重要，因为 心血管疾病在这项工作中要研究的具体目标是： 1.改进的椭圆中心（EC）采集技术。EC视图顺序将与 投影重建（PR）k空间采样，以利用这两种方法的内在优势。 将开发EC-PR技术的变体，以提供：（i）使用2D 零差（HD）重建;（ii）帧速率高达2 Hz的时间分辨研究;（iii）兼容性 与并行成像方法（如SENSE）配合，扫描时间缩短四倍;以及（iv）兼容性 结合SENSE和HD重建，可在给定分辨率下将扫描时间缩短六倍。 新方法将应用于对比增强和非对比增强MRA研究。 2.实时大剂量检测和跟踪。将开发检测和跟踪造影剂团注的方法 在真实的时间内以完全自动的方式通过血管系统， 风景该信息将允许生成患者特定的推注速度曲线，其可以引导推注速度曲线。 MR血管造影脉冲序列和控制床速度并优化患者的空间分辨率- 具体依据。 3.全面的神经血管检查新的采集和实时计算 将整合目标1和2的技术，以提供主动脉弓的全面血管造影， 大血管，颈动脉分叉，颅内动脉和大脑的引流静脉， 单次注射造影剂。检查期间的适度扫描床运动将允许扩展FOV的成像。

The broad, long-term objective of this work is to develop novel, time-efficient methods for MR data acquisition and corresponding real-time signal processing techniques to allow formation of MR images which portray the cardiovascular system with high spatial resolution. This is significant due to the high incidence of cardiovascular disease. Specific aims to be studied in this work are: 1. Modified Elliptical Centric (EC) Acquisition Techniques. The EC view order will be combined with projection reconstruction (PR) k-space sampling to exploit the intrinsic advantages of both approaches. Variants of the EC-PR technique will be developed to provide: (i) improved resolution for given time using 2D homodyne (HD) reconstruction; (ii)time-resolved studies with frame rates as high as 2 Hz; (iii) compatibility with parallel imaging methods such as as SENSE for four-fold reduction in scan time; and (iv)compatibility with a combination of SENSE and HD reconstruction for six-fold scan time reduction for given resolution. The new methods will be applied to contrast-enhanced as well as non-contrast-enhanced MRA studies. 2. Real-Time Bolus Detection and Tracking. Means will be developed to detect and track contrast bolus transit in real time in a totally automated way as it moves through the vasculature over an extended field of view. This information will allow the generation of patient-specific bolus velocity profiles which can guide the MR angiographic pulse sequence and control table velocity and optimize spatial resolution on a patient- specific basis. 3. The Comprehensive Neurovascular Examination. The new acquisition and real-time computation techniques of Aims 1 and 2 will be integrated to provide a comprehensive angiogram of the aortic arch and great vessels, the carotid bifurcations, the intracranial arteries, and the draining veins of the brain following a single injection of contrast. Modest table motion during the exam will permit imaging of the extended FOV.