Minimum Redundancy Spatiotemporal MRI

0201876布雷斯勒自70年代初诞生以来，S磁共振成像已成为主要的诊断成像工具。虽然早期的应用主要局限于静止物体，但近年来，MRI在心脏、功能或介入性成像等动态成像应用中也被证明非常有用。动态磁共振成像(D-MRI)面临的一个重要挑战是同时获得高空间分辨率和高时间分辨率。在过去的二十年里，已经开发了许多快速成像方法，包括快速扫描技术、用于并行采集的相控阵射频线圈和减少数据空间的采样。尽管快速磁共振成像取得了这些进展，但许多应用程序仍然严重依赖于额外的加速，几乎所有应用程序都可以从中受益。例如，3D多时相心脏成像、冠状动脉造影和斑块表征、无需屏气的心脏成像、扩散张量功能脑成像，以及具有高组织对比度和时间分辨率的介入性磁共振成像。本研究的总体目标是开发、实施和测试一个新的统一理论框架，用于最小冗余D-MRI数据采集和图像重建。在该框架中，动态成像被视为一个以时间为独立轴的高维图像重建问题。不是试图通过足够快的采集来冻结所有运动，而是在MRI序列设计、数据采集和图像重建的步骤中明确地考虑了采集过程中的时间变化。该方法将借鉴和扩展过去几年PI引入的理论和算法，这些理论和算法提供了显著加速成像过程的潜力。此外，将本项目中开发的理论和技术与快速扫描方法和基于相控阵射频线圈的方法相结合，将产生比任何一种单独方法更大的组合加速比。

0201876BreslerSince its inception in the early 70's, magnetic resonance imaging (MRI) has become a premier diagnostic imaging tool. Although its early applications were largely limited to stationary objects, MRI has also proven extremely useful, in recent years, for dynamic imaging applications, such as cardiac, functional or interventional imaging. An important challenge confronting dynamic MRI (D-MRI) is obtaining both high spatial and high temporal resolutions. Over the last two decades, many fast imaging methods including fast-scan techniques, phased array RF coils for parallel acquisition, and reduced sampling of the data space have been developed. In spite of these advances in fast MRI, many applications are still critically dependent on additional speedups, and virtually all applications could benefit from them. Examples include 3D multiphase cardiac imaging, coronary angiography and plaque characterization, cardiac imaging without breath-holding, diffusion-tensor functional brain imaging, and interventional MRI with high tissue contrast and temporal resolution.The general goal of the proposed research is to develop, implement and test a new unified theoretical framework for minimum-redundancy D-MRI data acquisition and image reconstruction. In this framework, dynamic imaging is treated as a higher-dimensional image reconstruction problem, with time being an independent axis. Instead of attempting to freeze all motion by sufficiently fast acquisition, time variation during acquisition is explicitly accounted for in the steps of MRI sequence design, data acquisition, and image reconstruction. The approach will draw on and extend theories and algorithms introduced by the PIs over the past few years, which offer the potential for significant speedups of the imaging process. Furthermore, combination of the theory and techniques developed in this project with fast scan methods and with methods based on phased-array RF coils will produce combined speedups, greater than any one of the individual approaches.