Non-contrast 4-D Dynamic MRA in Arteriovenous Malformation (AVM)

动静脉畸形 (AVM) 中的非对比 4-D 动态 MRA

• 批准号: 8598085
• 负责人: Danny JJ WANG
• 金额: $ 44.66万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-12-14 至 2016-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8598085
• 关键词: Aftercare; Anatomy; Angiography; Architecture; Arteries; Arteriovenous malformation; Blood; Blood Vessels; Blood Volume; Blood flow; Bolus Infusion; Brain; Bypass; Cerebral Aneurysm; Cerebrovascular Disorders; Cessation of life; Clinical; Contrast Media; Detection; Development; Diagnostic; Digital Subtraction Angiography; Disease; Evaluation; Goals; Gold; Hemorrhage; Image; Imagery; Injury; Intracranial Hemorrhages; Ionizing radiation; Kinetics; Label; Lead; Magnetic Resonance Imaging; Measurement; Measures; Methods; Modeling; Neurologic; Patients; Perfusion; Phase; Physiologic pulse; Procedures; Radial; Reference Standards; Resolution; Risk; Roentgen Rays; Sampling; Scanning; Scheme; Shunt Device; Speed; Spin Labels; Steno; Stress; Techniques; Testing; Time; Tracer; Validation; Veins; Venous; Water; Weight; base; blood flow measurement; brain tissue; feeding; hemodynamics; improved; malformation; public health relevance; research clinical testing; spatiotemporal; time use

DESCRIPTION (provided by applicant): An arteriovenous malformation (AVM) is a congenital vascular abnormality in the brain with direct connections between arteries and veins such that blood bypasses brain tissue. The primary presentation of AVM is intracranial hemorrhage which occurs in as many as 40-70% of patients and may lead to permanent injury or death. As the gold standard for the detection and evaluation of vascular malformations, conventional digital subtraction angiography (DSA) is an invasive procedure bearing risks of neurological complications, as well as risks of ionizing radiation and iodinated contrast. While superior for th delineation of vascular anatomy, DSA is not capable of providing quantitative assessments of blood flow or degree of shunt in an AVM. Existing MR techniques are suboptimal for quantifying the hemodynamics of vascular malformation, and the complexity of the vascular architecture is often inadequately demonstrated. Arterial spin labeling (ASL) is a noninvasive MRI technique that utilizes magnetically labeled blood water as an endogenous tracer for perfusion measurements. Due to the direct shunt between arteries and veins in AVMs, the labeled blood spins behave as an intravascular contrast agent, and can be utilized for visualizing the dynamic blood flow through feeding arteries, nidus and draining veins of an AVM. Furthermore, hemodynamic parameters such as blood flow, blood volume and mean transit time can be quantified by adapting the standard tracer kinetic model. We have recently developed such an entirely noninvasive and quantitative 4-D time-resolved dMRA technique by combining ASL with a segmented cine multiphase TrueFISP sequence. The goal of the present proposal is to further develop, validate and evaluate the clinical utility of 4-D non-contrast dMRA in assessing both the vascular architecture and hemodynamics of AVMs. In Aim 1, further technical development and optimization of 4-D non-contrast dMRA will be performed, including implementation of multi-bolus pulsed and pseudo-continuous ASL (pCASL) with vessel selective labeling; Cartesian sampling with view sharing; dynamic golden angle radial acquisition with k-space weighted image contrast (KWIC); in conjunction with parallel imaging and potentially compressed sensing. In Aim 2, validation of methods for quantifying blood flow and degree of shunt through AVMs using 4- D dMRA will be carried out by comparison with phase-contrast (PC) MRI and pCASL perfusion MRI. Finally in Aim 3, the clinical utility of the proposed 4-D dMRA technique will be evaluated in AVM patients by comparison with the reference standard of DSA, time-of-flight (TOF) MRA and T2 weighted MRI. Furthermore, repeated scans will be performed to test whether 4-D dMRA is able to detect changes of blood flow and degree of shunt through AVMs pre and post treatments. The proposed 4-D dMRA is expected to provide alternative and complementary approaches for conventional DSA and MRA/MRI techniques in quantitative assessments of hemodynamics in AVMs. It will be useful not only for evaluation of AVMs, but also for other cerebrovascular disorders such as steno-occlusive diseases and cerebral aneurysms. !

描述（由申请人提供）：动静脉畸形（AVM）是大脑中的一种先天性血管异常，动脉和静脉之间有直接连接，导致血液绕过脑组织。 AVM 的主要表现是颅内出血，多达 40-70% 的患者会发生颅内出血，并可能导致永久性损伤或死亡。作为检测和评估血管畸形的金标准，传统的数字减影血管造影（DSA）是一种侵入性手术，存在神经并发症的风险以及电离辐射和碘造影剂的风险。虽然 DSA 能够很好地描绘血管解剖结构，但它无法对 AVM 中的血流或分流程度进行定量评估。现有的 MR 技术对于量化血管畸形的血流动力学并不是最理想的，而且血管结构的复杂性往往没有得到充分的证明。动脉自旋标记 (ASL) 是一种无创 MRI 技术，利用磁性标记的血液作为内源性示踪剂进行灌注测量。由于 AVM 中动脉和静脉之间的直接分流，标记的血液自旋充当血管内造影剂，可用于可视化通过 AVM 的供血动脉、病灶和引流静脉的动态血流。此外，可以通过采用标准示踪剂动力学模型来量化血流动力学参数，例如血流量、血容量和平均通过时间。我们最近通过将 ASL 与分段电影多相 TrueFISP 序列相结合，开发了这种完全无创且定量的 4-D 时间分辨 dMRA 技术。本提案的目标是进一步开发、验证和评估 4-D 非对比 dMRA 在评估 AVM 的血管结构和血流动力学方面的临床效用。在目标 1 中，将进行 4-D 非对比 dMRA 的进一步技术开发和优化，包括实施具有血管选择性标记的多次推注脉冲和伪连续 ASL (pCASL)；具有视图共享的笛卡尔采样；具有 k 空间加权图像对比度 (KWIC) 的动态黄金角径向采集；与并行成像和潜在的压缩传感相结合。在目标 2 中，将通过与相位对比 (PC) MRI 和 pCASL 灌注 MRI 进行比较，对使用 4-D dMRA 量化通过 AVM 的血流和分流程度的方法进行验证。最后，在目标 3 中，将通过与 DSA、飞行时间 (TOF) MRA 和 T2 加权 MRI 的参考标准进行比较，评估所提出的 4-D dMRA 技术在 AVM 患者中的临床效用。此外，还将进行重复扫描，以测试4-D dMRA是否能够检测治疗前后AVM的血流变化和分流程度。所提出的 4-D dMRA 有望为 AVM 血流动力学定量评估中的传统 DSA 和 MRA/MRI 技术提供替代和补充方法。它不仅可用于评估动静脉畸形，还可用于其他脑血管疾病，例如狭窄闭塞性疾病和脑动脉瘤。 ！