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: 6795945
• 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/6795945
• 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、射频线圈硬件以及图像重建和信号处理方法，以允许在患者床位连续移动期间执行MR数据。与当前固定的多工位方法相比，这种方法提高了时间效率，并消除了工位之间的亮度不连续。此外，使用实时图像重建允许实时调整台面速度，以匹配在特定患者的基础上观察到的对比剂的传递。在下肢使用多个线圈的新方法将使采集时间减少两倍。该项目的长期目标是实现高分辨率全身核磁共振。该项目的总体假设是，高分辨率的动脉30期对比增强磁共振血管成像可以使用实时的、针对患者的采集结合连续移动的床进行。拟研究的具体项目包括： 1.连续床位运动时的MRI数据采集。将开发用于连续工作台运动过程中的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。将优化相位编码顺序，并研究扫描过程中板材厚度和位置的变化。将开发针对磁场不均匀和梯度非线性的校正算法。 2.双线圈成像。为了利用腿部成像中的非连续视野，将开发一种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相互隔离，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。预计这将使给定分辨率的采集时间缩短两倍，而不会产生与SENSE相关的处理和噪声放大因素。 3.周边径流的三维MRA研究。项目1和2中开发的技术将适用于对周围血管系统进行成像。最初，在高分辨率3D扫描期间，使用快速2D模式跟踪腿部测试推注将指导台面速度的选择。最终，跟踪将使用透视触发、团注前沿的实时确定和动态速度控制来实时完成。