Accelerated Neuro-MRA Using Compressed Sensing and Constrained Reconstruction

 描述(由申请人提供)：中风的巨大经济和社会负担需要更好的工具来评估脑血管系统。磁共振成像(MRI)广泛应用于对出现中风症状的患者的评估和治疗，是大多数诊断神经成像的标准护理。在完整的动脉瘤和动脉粥样硬化斑块的情况下，MRI提供了竞争技术所无法提供的独特的对比机制。在这两种疾病中，内皮壁与血液施加的血流动力之间的相互作用已经建立。作用力和随后的血管发病机制之间的确切关系尚不确定；然而，易导致狭窄和动脉瘤形成的血流条件已被确定。MRI采用血流编码(4D FLOW)，具有无创探测潜在的恶性血流动力学情况的潜力。此外，血管内皮细胞状态可以用核磁共振成像来探测，利用黑血成像来可视化外源性对比剂的摄取。最近的MRI研究表明，造影剂后动脉壁强化(AWE)与病变不稳定之间存在联系，这可能表明AWE是一种衡量活动性炎症和重塑的指标。血流动力学和炎症的同时描述具有巨大的潜力来改进涉及血管壁功能障碍或活动性重塑的疾病的活体特征。遗憾的是，目前的MRI方法由于复杂和湍流、覆盖范围不足以及空间分辨率的限制而经常受到信号损失的影响。此外，许多独特的MRI对比机制，如4D Flow，由于扫描时间延长，需要精确量化所需的分辨率，因此不适用于临床成像。这项建议提出了下一代加速成像技术，用于综合评估颅内狭窄和动脉瘤，通过新图像采集和限制性重建方法的共生开发，将与计算机断层扫描(CT)相媲美并超越CT。特别是，我们的目标是开发稳健的定量MRA(QMRA)方法，这是一种多对比度高分辨率血管成像范例。为了实现伪影减少、空间分辨率和信噪比所需的组合，我们利用了新颖的超短回波时间采集技术和基于稳健模型的重建技术相结合的采集策略。通过更快速、更高效地获取数据，这些策略可以提高空间分辨率，同时减少复杂流程中的诊断模糊伪影。我们的目标是利用这些进展将血管造影MRI与高速加速的4D-Flow和血管壁成像相结合，以研究完好的颅内动脉瘤和动脉粥样硬化病变中血管重构、炎症和血流动力学之间的相互作用。最终目的是利用非侵入性成像观察恶性血流动力学状况与动脉壁强化之间的相关性，这可能提供新的临床治疗范例，并改善对一系列神经血管疾病的管理。

 DESCRIPTION (provided by applicant): The enormous economic and social burden of stroke demands better tools to assess the cerebrovascular system. Magnetic Resonance Imaging (MRI) is widely used in the evaluation and management of patients presenting with symptoms of stroke and is standard of care for most diagnostic neurological imaging. In the case of intact aneurysms and atherosclerotic plaques, MRI offers unique contrast mechanisms unavailable from competing technologies. In both these diseases, an interaction of the endothelial wall with hemodynamic forces exerted by blood has been established. The exact relationship between forces and subsequent vascular pathogenesis is uncertain; however, flow conditions that predispose subjects to stenosis and aneurysm formation have been identified. MRI with flow encoding (4D flow), holds potential to non-invasively probe potentially hostile hemodynamic conditions. Furthermore, endothelial status can be probed with MRI utilizing black blood imaging to visualize the uptake of exogenous contrasts. Recent MRI studies suggest a link between post-contrast arterial wall enhancement (AWE) and lesion instability, potentially indicating AWE as a measure of active inflammation and remodeling. The simultaneous depiction of hemodynamics and inflammation holds tremendous potential to improve the in-vivo characterization of diseases involving vessel wall dysfunction or active remodeling. Unfortunately, current MRI methods often suffer from signal loss due complex and turbulent flow, inadequate coverage, and limitations in spatial resolution. Furthermore, many unique MRI contrast mechanisms, such as 4D flow, are not practical for clinical imaging due to extended scan times with required resolutions for accurate quantification. This proposal suggests a next generation of accelerated imaging technology for the comprehensive evaluation of intracranial stenoses and aneurysms that will rival and surpass computed tomography (CT) through the symbiotic development of new image acquisition and constrained reconstruction methods. In particular, we aim to develop methods for robust quantitative MRA (qMRA), a multi-contrast high resolution vascular imaging paradigm. In order to achieve the required combinations of artifact reduction, spatial resolution and signal-to-noise ratio, we harness acquisition strategies utilizin novel ultra-short echo time acquisition techniques in combination with robust model based reconstruction techniques. By acquiring data more rapidly and in a more efficient manor, these strategies allow improved spatial resolution while mitigating diagnostic obscuring artifacts from the complex flow. We aim to harness these advances to into a synergistic combination of angiographic MRI with highly accelerated 4D-flow and vessel wall imaging to investigate the interactions between vascular remodeling, inflammation, and hemodynamics in intact intracranial aneurysms and atherosclerotic lesions. The ultimate goal is to observed correlations between hostile hemodynamic conditions and arterial wall enhancement utilizing non-invasive imaging, which may provide new clinical treatment paradigms and improve the management of a broad array of neurovascular diseases.