Accelerated Neuro-MRA Using Compressed Sensing and Constrained Reconstruction

 描述（由申请人提供）：卒中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）广泛用于评估和管理出现卒中症状的患者，是大多数诊断性神经成像的标准治疗。在完整动脉瘤和动脉粥样硬化斑块的情况下，MRI提供了竞争技术无法提供的独特对比机制。在这两种疾病中，已经建立了内皮壁与血液施加的血流动力学力的相互作用。力和随后的血管发病机制之间的确切关系尚不确定;然而，已经确定了使受试者易于狭窄和动脉瘤形成的流动条件。具有流动编码（4D流动）的MRI具有非侵入性探测潜在不利血流动力学条件的潜力。此外，可以利用MRI探测内皮状态，利用黑血成像来可视化外源性对比剂的摄取。最近的MRI研究表明造影后动脉壁增强（AWE）和病变不稳定性之间存在联系，可能表明AWE可作为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，以改善涉及血管壁功能障碍或主动重塑的疾病的体内表征。不幸的是，目前的MRI方法经常遭受由于复杂和湍流的信号损失、覆盖不足以及空间分辨率的限制。此外，许多独特的MRI对比机制，例如4D流，由于具有精确量化所需的分辨率的延长的扫描时间，对于临床成像是不实用的。该提案提出了下一代加速成像技术，用于颅内狭窄和动脉瘤的综合评价，通过新的图像采集和约束重建方法的共生发展，该技术将与计算机断层扫描（CT）竞争并超越CT。特别是，我们的目标是开发鲁棒定量MRA（qMRA），多对比度高分辨率血管成像范例的方法。为了实现伪影减少、空间分辨率和信噪比的所需组合，我们利用利用新颖的超短回波时间采集技术与基于鲁棒模型的重建技术相结合的采集策略。通过更快速且更有效地获取数据，这些策略允许提高空间分辨率，同时减轻来自复杂流的诊断模糊伪影。我们的目标是利用这些进展，将血管造影MRI与高度加速的4D血流和血管壁成像协同组合，以研究完整颅内动脉瘤和动脉粥样硬化病变中血管重塑、炎症和血流动力学之间的相互作用。最终目标是利用非侵入性成像观察不利的血流动力学条件和动脉壁增强之间的相关性，这可能提供新的临床治疗范例，并改善广泛的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.