Non-Contrast-Enhanced Velocity-Selective MR Angiography at 3T for Cerebrovascular Diseases

项目摘要 脑血管疾病作为所有社会死亡和残疾的主要原因之一，给人们带来了巨大的影响。 全世界的社会经济负担。脑血管造影在鉴别诊断中起着不可或缺的作用， 神经系统疾病患者的预后展望、治疗管理和治疗后随访 血管病理学，如中风、动脉狭窄、 脑静脉窦血栓形成 , 动静脉畸形, 和动脉瘤。传统上，基于导管的 X 射线血管造影术被认为是诊断疾病的黄金标准。 脑血管评估。对比增强 (CE) MRA 可实现大空间覆盖、高空间覆盖 分辨率和快速采集。然而，动脉的可视化常常被静脉增强所掩盖。在 此外，基于 Gd 的 CE MRA 的安全性因担心发生肾源性病变而受到挑战。 肾功能受损患者的系统性纤维化（NSF）及其报告 Gd在大脑中沉积 即使不存在肾脏疾病 。因此，非对比增强磁共振血管造影 (NCE MRA) 已迅速 旨在最大限度地降低风险并降低成本。临床实践中主要的 NCE 脑部 MRA 是 3D 时间- 飞行 (TOF) 方法，已知该方法的血管造影覆盖范围有限且对慢血流的描绘效果较差。 新开发的动脉自旋标记 (ASL) MRA 可以提供大空间覆盖或 4D 时间分辨 MRA 动态充盈动脉。 ASL 方法的缺点是信号效率降低， 由于需要两次采集来减去标记和未标记的血液信号，因此延长了扫描时间， 以及对运动引起的重合失调的敏感性。我们最近证明了一种新颖的速度的可行性 用于 3T 大脑应用的选择性 (VS) MRA 方法，这是一种非减法技术，允许 大覆盖、慢流描绘。旨在结合 TOF 和 ASL MRA 的有利方面 方法，我们提出了 VS MRA 的许多技术进步，以渲染 3D 动脉造影、静脉造影和 4D 时间分辨 MRA。本研究的目的是 首先进一步开发这些 VS 脑 MRA 技术 在流动模型和健康受试者中（目标 1），然后评估患有以下疾病的患者的 3D VS MR 动脉造影： 脑静脉窦患者的颈动脉或颅内狭窄（目标 2）和 3D VS MR 静脉造影 血栓形成（目标 3），最后评估 AVM 或动脉瘤患者的 4D 时间分辨 VS-MRA （目标 4）。 拟议的 NCE VS MRA 技术预计不仅对大脑具有临床价值，而且对大脑也具有临床价值。 对身体的其他部位也有好处，尤其有益 儿童、孕妇、糖尿病患者或 肾功能受损 。

Project Abstract Cerebrovascular diseases, as one of the leading causes of death and disability in all societies, impose enormous social-economic burden worldwide. Cerebral angiography plays an indispensable role in differential diagnosis, prognosis outlook, therapeutic management, and follow-up after treatment for patients with neurological vasopathology, such as stroke, arterial stenosis, cerebral venous sinus thrombosis , arteriovenous malformation, and aneurysm. Traditionally, catheter-based X-ray angiography has been considered the gold standard for cerebrovascular assessment. Contrast-enhanced (CE) MRA allows large spatial coverage, high spatial resolution, and rapid acquisition. However, arterial visualization are often obscured by venous enhancement. In addition, the safety of Gd based CE MRA has been challenged for the concerns of developing Nephrogenic Systemic Fibrosis (NSF) for patients with impaired kidney function and the reports of Gd deposition in the brain even when no kidney disease is present . Thus non-contrast-enhanced MR angiography (NCE MRA) has rapidly evolved to minimize risk and lower cost. The primary NCE cerebral MRA in clinical practice is the 3D time-of- flight (TOF) method, which is known to have limited angiographic coverage and poor delineation of slow flow. Newly developed arterial spin labeling (ASL) MRA can provide either large spatial coverage or 4D time-resolved MRA with dynamic filling of arteries. The drawback of the ASL methods are the reduced signal efficiency, lengthened scan times due to the required two acquisitions for subtraction of labeled and unlabeled blood signal, and sensitivity to motion-induced misregistration. We recently demonstrated feasibility of a novel velocity- selective (VS) MRA approach for cerebral applications at 3T, which is a non-subtractive technique and allows large coverage and slow-flow depiction. Aiming to incorporate favorable aspects of both TOF and ASL MRA methods, we propose numerous technical advances for VS MRA to render 3D arteriography, venography and 4D time-resolved MRA. The purpose of this study is first to further develop these VS cerebral MRA techniques in flow phantoms and healthy subjects (Aim 1), then to evaluate the 3D VS MR arteriography in patients with carotid or intracranial stenosis (Aim 2) and the 3D VS MR venography in patients with cerebral venous sinus thrombosis (Aim 3), and finally to evaluate the 4D time-resolved VS-MRA in patients with AVM or aneurysm (Aim 4). The proposed NCE VS MRA techniques are expected to show clinical values not only for the brain, but also for the rest of the body, and especially benefit children, pregnant women, and patients with diabetes or impaired kidney function .