Development of a practical quantitative non-contrast approach for cerebrovascular MRI

颈动脉Gd增强前后的多对比MRI序列 与单纯斑块相比，斑块可以显著提高中风风险的确定 颈动脉狭窄测量。而改进的斑块特征描述与 MRI可以用来更好地个体化治疗患有颈动脉疾病的退伍军人，它的使用 一直受到限制，因为它需要基于Gd的造影剂，延长检查时间 时代，以及广泛的口译培训。要解决这些剩余的限制，并 将我们的领域推向临床应用，我们的多中心研究团队将 结合我们在颈动脉MRI方面的广泛集体经验，开发一种新的快速非 自动准确识别颈动脉显像剂对比定量方法 易受攻击的斑块成分。我们的目标是建立一种准确的颈动脉检测方法 用1到3个磁共振序列可以获得斑块映射，需要10分钟的≤ 总的斑块检查。为了实现这一目标，我们将巩固我们不同的 定量颈动脉MRI序列分为两种不同的测量方法 定量参数(NEW1和NEW2)。然后我们将对这两种方法进行比较 相互对比和对照传统的多序列对比度增强 颈动脉磁共振成像方法(COV)在100例退伍军人颈动脉疾病中的应用 重复访问的扫描将用于测试参数的重复性 并将使用高性能颈型专用(NSS)进行测量 颈动脉线圈。我们的假设是易损的颈动脉斑块成分(斑块内 出血、富含脂质的坏死灶、钙化、斑块总体积、细小或 纤维帽破裂)可以使用快速获得的定量MRI准确地识别 参数(弛豫时间、扩散系数和质子密度信号强度)。 具体地说，在测量斑块方面，NEW1或NEW2或两者都不比CONV差 成分与组织学相当或比Conv更准确。目标1将 确定NEW1和NEW2中哪一个更具可重复性，目标2将决定 在斑块成分测定中，其中一种或两种方法都不逊于Conv，目标3 将确定NEW1、NEW2和CONV三种方法的相对精度 与组织学相比。这项研究将提供快速可靠的定量 进行全面的颈动脉检查。这将使面临风险的退伍军人受益 中风，但目前未得到充分治疗，因为直径缩小不符合 干预的标准。它将使其他有狭窄但稳定的斑块的人避免 做手术。经过演示，该方法可以自动识别斑块特征 如果没有5个学术VAMC的专家监督，这项技术将直接 适用于社区医院环境。尽管这项技术已经 在单一供应商的MRI平台上开发的NSS线圈和相关脉冲 开发的序列将可传输到任何MRI扫描仪硬件并适用 对其他血管区域和非血管组织进行成像。这种快速的非对比磁共振成像 该方案将从根本上改变脑血管疾病的临床管理。

Multi-contrast MRI sequences before and after gadolinium enhancement of the carotid plaque can significantly improve determination of stroke risk compared with simple carotid stenosis measurements. While the improved depiction of plaque features with MRI can be used to better individualize therapy for veterans with carotid disease, its use has been limited because it requires gadolinium-based contrast agents, extended exam times, and extensive interpretive training. To address these remaining limitations and move our field forward into clinical application, our multicenter team of investigators will combine our extensive collective experience in carotid MRI to develop a novel rapid non- contrast quantitative carotid imaging method to automatically and accurately identify vulnerable plaque components. Our goal is to establish a method for accurate carotid plaque mapping that can be obtained with 1 to 3 MRI sequences taking ≤10 minutes for the total plaque exam. To accomplish this goal, we will consolidate our different quantitative carotid MRI sequences into two different methods of measuring these quantitative parameters (NEW1 and NEW2). We will then compare these two methods against each other and against the conventional multi-sequence contrast enhanced carotid MRI method (CONV) in a study of 100 veterans with carotid disease at our 5 VAMC’s. Scans from repeat visits will be used to test repeatability of the parametric measurements and will be performed with high-performance neck-shape-specific (NSS) carotid coils. Our hypothesis is that vulnerable carotid plaque components (intraplaque hemorrhage, lipid rich necrotic core, calcification, total plaque volume, and thin or ruptured fibrous cap) can be accurately identified using rapidly acquired quantitative MRI parameters (relaxation times, diffusion coefficient, and proton density signal intensity). Specifically, that NEW1 or NEW2 or both are non-inferior to CONV in measuring plaque components and equivalent or more accurate than CONV relative to histology. Aim 1 will determine whether NEW1 or NEW2 is more repeatable, Aim 2 will determine whether either or both are non-inferior to CONV in plaque component determination, and Aim 3 will determine the relative accuracy of the three methods, NEW1, NEW2, and CONV compared with histology. This research will provide a rapid and reliable quantitative approach for a comprehensive carotid artery exam. This will benefit veterans at risk for stroke but presently under-treated because the diameter narrowing does not meet criteria for intervention. It will spare others with stenotic but stable plaque the risk of surgery. After demonstrating this method can automatically identify plaque features without expert oversight at the 5 academic VAMCs, this technique will be directly applicable in the community hospital setting. Although the technology has been developed on a single vendor’s MRI platform, the NSS coils and related pulse sequences developed will be transferrable to any MRI scanner hardware and applicable to imaging other vascular territories and nonvascular tissue. This rapid non-contrast MRI protocol will fundamentally change the clinical management of cerebrovascular disease.