Long Field Of View MRA Using Continuous Table Motion

使用连续工作台运动的长视场 MRA

• 批准号: 6653234
• 负责人: Stephen J Riederer
• 金额: $ 36.13万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-01 至 2006-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6653234
• 关键词: angiography; bioimaging /biomedical imaging; biomedical equipment development; clinical research; human subject; image enhancement; magnetic resonance imaging; method development; swine

DESCRIPTION (provided by applicant): We propose to develop the MRI physics acquisition techniques, the RF coil hardware, and the image reconstruction and signal processing methods to allow MR data to be performed during continuous motion of the patient table. Compared to the current, fixed, multi-station approach this offers improved time efficiency and eliminates brightness discontinuities between stations. Further, the use of real-time image reconstruction permits the table velocity to be adjusted in real time to match the observed transit of the contrast bolus on a patient-specific basis. New approaches for use of multiple coils in the lower extremities will permit two-fold reduced acquisition time. The long term goal of the project is to allow high resolution whole body MRI. The overall hypothesis of this project is that high resolution, arterial phase 30 contrast-enhanced MR angiography can be performed using real-time, patient-specific acquisition in conjunction with a continuously moving table. Specific projects to be studied are: 1. MRI Data Acquisition During Continuous Table Motion. The specific technique for data acquisition and correction during continuous table motion will be developed. The tradeoffs between field of view, spatial and time resolution, and velocity will be studied. Phase encode orders will be optimized, and alteration of slab thickness and position during the scan will be studied. Correction algorithms will be developed for magnetic field inhomogeneities and gradient non-linearities. 2. Dual-Coil Imaging. To exploit the non-contiguous fields of view in imaging the legs, an approach using two distinct transmit and receive coils will be developed. By isolating the response of each coil from the other, it is possible to collect data from each leg separately and simultaneously using the same pulse sequence. This is expected to provide a two-fold reduction in acquisition time for given resolution without the processing and noise amplification factors associated with SENSE. 3. Peripheral Runoff Study 3D MRA. The techniques developed in Projects 1 and 2 will be adapted to imaging the peripheral vasculature. Initially, tracking of a test bolus down the legs using a rapid 2D mode will guide the selection of table velocity during the high resolution 3D scan. Eventually, tracking will be done in real-time using fluoroscopic triggering, real-time determination of the bolus front, and dynamic velocity control.

描述（由申请人提供）：我们建议开发MRI物理采集技术、RF线圈硬件以及图像重建和信号处理方法，以允许在患者扫描床连续运动期间执行MR数据。与目前的固定多站方法相比，这提供了改进的时间效率，并消除了站之间的亮度不连续性。此外，实时图像重建的使用允许真实的调整检查床速度，以在患者特定的基础上匹配观察到的对比剂团的传输。在下肢使用多个线圈的新方法将使采集时间缩短两倍。该项目的长期目标是实现高分辨率的全身MRI。本项目的总体假设是，可以使用实时、患者特定采集结合连续移动扫描床进行高分辨率动脉期30对比度增强MR血管造影。拟研究的具体项目如下： 1.扫描床连续运动期间的MRI数据采集。将开发在连续工作台运动期间进行数据采集和校正的具体技术。将研究视场、空间和时间分辨率以及速度之间的权衡。对相位编码顺序进行优化，并研究扫描过程中板坯厚度和位置的变化。将针对磁场不均匀性和梯度非线性开发校正算法。 2.双线圈成像。为了利用腿部成像中的非连续视场，将开发使用两个不同的发射和接收线圈的方法。通过将每个线圈的响应与另一个隔离，可以使用相同的脉冲序列分别并同时从每个支路收集数据。这有望在给定分辨率下将采集时间缩短两倍，而无需与SENSE相关的处理和噪声放大因素。 3.外周径流研究3D MRA。项目1和2中开发的技术将适用于外周血管成像。最初，使用快速2D模式沿腿跟踪测试团将在高分辨率3D扫描期间指导扫描床速度的选择。最终，将使用荧光透视触发、实时确定团注前沿和动态速度控制来实时完成跟踪。