Characterization of intracranial vessel wall morphology and inflammation using 3D high resolution MRI

项目摘要 脑血管疾病是中风的主要来源。然而，临床医生治疗颅内 血管性疾病的患者常常处于两难境地，因为最有效的治疗方法是潜在的病理生理学 可能的进展是模糊的。直到最近，病理学来源的非侵入性评估-血管 墙-不可能。尽管磁共振成像（MRI）技术的进步显示出潜在的 对于血管壁成像（VWI），这些方法的真实性能度量的定义很差。真正的 对于壁成分，特别是炎性成分的分辨率和表征， 在实践者之间建立和变化。该项目将实施新的方法，在体内颅内 VWI使用高场强MRI（3 T和7 T）。这一目标将通过理论设计和 模拟，体外模型，体内实施，组织学验证。 首先：我们将优化高分辨率（亚0.5mm各向同性）3D黑血快速自旋回波MRI（称为SPACE 在Siemens平台上）在3 T和7 T下进行全脑颅内VWI。血管壁信噪比， 将模拟与周围脑脊液（CSF）或脑实质的对比度， 优化这将在体外模型上进行验证，并对10名健康志愿者和10名 颅内血管疾病患者。我们亦会采用压缩感知方法， 长时间采集的扫描时间（目前约为10分钟），使其在临床上可行。第二：3D空间， 超短回波时间（UTE）序列和T2* 标测/定量磁化率标测（QSM）方法 用于使用超小型超顺磁性氧化铁（USPIO）造影剂检测炎症， 在USPIO体模中开发并验证了一系列浓度。这些方法将得到优化 检测10例颅内斑块患者的USPIO摄取，并确定最佳方法。 在计划手术前即刻进行的成像评估中确认摄取位置 将在10例颅内动脉瘤患者中进行组织学检查。第三：3 T成像的能力， 表征高风险血管壁特征（如斑块内出血、腔内血栓、钆 增强和USPIO摄取）与7 T扫描相比，将对30名患者进行评估， 脑血管疾病 项目的成功实施将提供表征颅内血管高风险特征的方法 可以在临床上用于根据患者具体情况评估卒中风险， 跨供应商平台验证。这些方法可用于指导针对性治疗，提高疗效。 卒中结局-直接支持国家心肺血液研究所的使命。

Project Summary Cerebrovascular disease is a major source of stroke. However, clinicians treating patients with intracranial vascular disease are often in a quandary as to the most effective treatment as the underlying pathophysiology and likely progression is obscure. Until recently, non-invasive evaluation of the source of pathology - the vessel wall - was not possible. Although advances in Magnetic Resonance Imaging (MRI) technology show potential for vessel wall imaging (VWI), the true performance metrics of these approaches are poorly defined. The true resolution and the characterization of wall components, specifically inflammatory components, have not been established and vary among practitioners. This project will implement new approaches to in vivo intracranial VWI using high field strength MRI (at 3T and 7T). This goal will be achieved with theoretical design and simulations, in vitro models, in vivo implementation, with histology validation. First: we will optimize high-resolution (sub 0.5mm isotropic) 3D black blood fast-spin-echo MRI (termed SPACE on Siemens platforms) at 3T and 7T for whole brain intracranial VWI. The vessel wall signal to noise ratio, sharpness, and contrast to surrounding cerebrospinal fluid (CSF) or brain parenchyma will be simulated and optimized. This will be validated on in vitro models and with in vivo scanning of 10 healthy volunteers and 10 patients with intracranial vascular disease. We will also implement compressed sensing method to reduce the scan time of the long acquisition (currently around 10 minutes) to make it clinically feasible. Second: 3D SPACE, Ultra-short echo time (UTE) sequences and T2* mapping/quantitative susceptibility mapping (QSM) methods for detecting inflammation using Ultra-Small Super-Paramagnetic Iron Oxide (USPIO) contrast agents will be developed and validated in USPIO phantoms with a range of concentrations. These methods will be optimized to detect USPIO uptake in 10 patients with intracranial plaques, and the best approaches will be determined. Confirmation of the location of uptake assessed on imaging performed immediately prior to scheduled surgery will be sought on histology in 10 patients with intracranial aneurysms. Third: The ability of 3T imaging to characterize high-risk vessel wall features (such as intraplaque hemorrhage, intra-luminal thrombus, gadolinium enhancement, and USPIO uptake) will be assessed compared to scanning at 7T on 30 patients with cerebrovascular disease. Successful project conduct will provide methods to characterize the high-risk features of the intracranial vessel wall that could be clinically used to evaluate risk of stroke on a patient-specific basis and with a tool for validation across vendor platforms. These methods could be used to guide patient-specific therapy and improve stroke outcome – directly supporting the mission of the National Heart, Lung, and Blood Institute.