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导致死亡和残疾的主要原因之一，给人们造成了巨大的 世界范围内的社会经济负担。脑血管造影在鉴别诊断中起着不可或缺的作用， 神经科患者的预后展望、治疗管理和治疗后的随访 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， 还有动脉瘤。传统上，基于导管的X射线血管造影术一直被认为是 脑血管评估。对比度增强(CE)MRA可实现大空间覆盖、高空间 分辨率和快速获取。然而，动脉显影常常因静脉强化而变得模糊。在……里面 此外，基于Gd的CE MRA的安全性也因开发肾病的担忧而受到挑战 肾功能受损患者的系统性纤维化(NSF)及相关报道 Gd在大脑中的沉积 即使在没有肾病的情况下 。因此，非对比增强磁共振血管成像(NCE MRA)迅速 演变为将风险降至最低并降低成本。临床上主要的NCE脑MRA是3D-Time-Of 飞行(TOF)方法，这是众所周知的有限的血管造影覆盖范围和较差的慢流描绘。 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 动脉动态充盈的磁共振血管成像。ASL方法的缺点是信号效率降低， 由于减去标记和未标记血液信号所需的两次采集而延长了扫描时间， 以及对运动引起的配准错误的敏感性。我们最近证明了一种新型速度的可行性- 用于3T脑部应用的选择性(VS)MRA方法，这是一种非减影技术，允许 覆盖面大，描绘慢流。旨在结合TOF和ASL MRA的优点 方法：我们提出了VS MRA的许多技术进展，用于显示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 在流动模体和健康受试者(目标1)中，然后评估3D和MR动脉造影在 脑静脉窦患者的颈动脉或颅内狭窄(AIM 2)和3D与MR静脉成像 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)。 被提议的NCE VS MRA技术预计将不仅显示出对大脑的临床价值，而且 对身体的其他部分也有好处，特别是对 儿童、孕妇和糖尿病患者或 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 .