Functional Magnetic Resonance Angiography (fMRA) of the Brain

脑部功能磁共振血管造影 (fMRA)

基本信息

批准号：
7860440
负责人：
PATRICK Alan TURSKI
金额：
$ 21.82万
依托单位：
UNIVERSITY OF WISCONSIN-MADISON
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-06-15 至 2011-09-30
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): During the past decade our group has developed highly accelerated MR angiographic techniques based on undersampled radial acquisition, constrained reconstruction, and phase contrast imaging. Three basic modes of functional MRA (fMRA) will be implemented using 3D radial acquisition (VIPR). These are: 1. Contrast-enhanced (CE) time-resolved angiography with highly constrained reconstruction (HYPR) 2. Undersampled phase contrast imaging 3. HYPR processed CE-MRA using the phase contrast data for the composite image (HYPR FLOW) See Figure 1 in specific aims for an overview of the three modes. The first mode typically provides acceleration factors of 20 to 200 relative to non-accelerated, Nyquist- satisfying Cartesian acquisition with noise factors an order of magnitude less than for parallel imaging. The phase contrast mode provides a method for non-CE angiography with excellent isotropic spatial resolution. This information permits the measurement of flow and pressure gradients in small vessels, adding a new dimension to non-invasive angiography. In the third mode, which also provides flow derived information, undersampling factors of up to 1000 relative to the Nyquist requirements have been achieved, providing voxel volumes an order of magnitude smaller than competing techniques, with temporal resolution of about 0.75 seconds. We propose to optimize these acquisition and reconstruction methods and to begin preliminary investigations of the feasibility of new applications such as relative wall shear stress measurement and pressure gradients. We will use simulations, phantom studies, volunteers and patients to determine the range of spatial and temporal resolution required for various applications and the sampling and SNR requirements for accurate determination of flow-derived quantities. We will obtain pilot studies in patients with altered flow conditions related to intracranial arterial stenosis, aneurysm and arteriovenous malformations. The data will be processed to provide a temporal series, displays of velocity, volume flow, relative wall shear stress and pressure gradients. PUBLIC HEALTH RELEVANCE: Functional Magnetic Resonance Angiography (fMRA) is a method to visualize the vascular structures of the brain. The technique has benefits over current methods in that it covers the entire brain and provides temporal information, high spatial resolution and flow dynamics. It is of minimal risk compared to conventional catheter based angiography and is thus better suited for the evaluation of atherosclerotic disease in elderly patients. It is a major advance in the evaluation of patients with atherosclerotic disease, brain aneurysms and vascular malformations, which are the leading causes of stoke in the US.

描述（由申请人提供）：在过去的十年中，我们的小组基于不足采样的径向采集，受限的重建和相比造影剂成像开发了高度加速的MR血管造影技术。将使用3D径向采集（VIPR）实施三种基本功能MRA（FMRA）。这些是：1。具有高度约束重建（HYPR）2的对比度增强（CE）时间分辨血管造影。使用复合图像（HYPR流）的相对造影剂数据（HYPR流）在特定的三种模式概述的特定目的中，使用图1参见图1。第一种模式通常提供20至200的加速度因子，相对于未加速的，令人满意的笛卡尔采集，噪声因子比平行成像小于噪声因子的数量级。相位造影剂模式为具有出色的各向同性空间分辨率的非CES造影术提供了一种方法。该信息允许在小血管中测量流量和压力梯度，从而为非侵入性血管造影增加了新的维度。在第三个模式下，还提供了流量导出的信息，相对于Nyquist要求，最多可提供1000个的采样因子，从而提供比竞争技术小的数量级，而时间分辨率约为0.75秒。我们建议优化这些采集和重建方法，并开始对新应用的可行性进行初步研究，例如相对壁剪应力测量和压力梯度。我们将使用模拟，幻影研究，志愿者和患者来确定各种应用所需的空间和时间分辨率的范围以及准确确定流量衍生数量的采样和SNR要求。我们将获得与颅内动脉狭窄，动脉瘤和动静脉畸形有关的流动条件改变患者的试点研究。数据将被处理以提供时间系列，速度，体积流量，相对壁剪应力和压力梯度的显示。公共卫生相关性：功能磁共振血管造影（FMRA）是一种可视化大脑血管结构的方法。该技术比当前方法具有好处，因为它涵盖了整个大脑，并提供时间信息，高空间分辨率和流动动态。与传统的基于导管的血管造影相比，它的风险很小，因此更适合评估老年患者的动脉粥样硬化疾病。这是评估动脉粥样硬化疾病，脑动脉瘤和血管畸形的患者的重大进步，这是美国斯托克的主要原因。