In vivo insights of small vessel changes with age using USPIO-enhanced MRI

项目摘要/摘要：微血管动脉系统在输送氧气和 葡萄糖，以满足大脑的高代谢需求。最近，微血管的异常已经被 越来越多地被认为是许多神经疾病的来源或基础，包括与年龄相关的痴呆症。 今天，衰老引起的结构和功能变化的机制在很大程度上仍然不清楚，而且 迫切需要活体表征小血管在生命过程中如何老化。 雄性和雌性成虫。尽管核磁共振成像能够在分辨率为 今天，它还没有被用来在平面分辨率下研究人体体内的微血管细节 为100μm或更小。我们已经开发出一种方法，通过这种方法来改变动脉的敏感性，使用 超小超顺磁性氧化铁(USPIO)，使其能够同时成像细小的动脉和静脉 磁化率加权成像(SWI)和定量磁化率图(QSM)观察微血管 不到100μm。我们对这项提议的兴趣是将各种医学和科学领域的专家聚集在一起 例如磁共振物理、图像处理和重建等领域，以开发一种我们所指的新技术 超高分辨率USPIO增强MR动脉和静脉造影(USPIO+-MRAV)。我们会带上 利用USPIO的绽放效应和敏感度的变化来创造新的成像手段 在3T和7T磁共振扫描上，小动脉和小静脉均位于50μm~100μm水平。我们希望有一个 临床上可行的方法，以3D血管为基础，创建大脑血管结构的“微血管指纹” 跟踪以评估常规成像所不具备的微血管拓扑和分布。我们 将开发血管密度和毛细血管密度的定量测量方法来评估与年龄相关的变化 一组年龄在18岁到85岁之间的健康志愿者。如果成功，这项创新技术有望 提供有关如何检测和解释与年龄相关的微血管改变的基本见解 活体脑成像。

Project Summary / Abstract: The microvascular arterial system plays a key role in delivering oxygen and glucose to fulfill the high metabolic demand of the brain. Recently, microvascular abnormalities have been increasingly identified as the source or basis of many neurologic disorders including age-related dementia. Today, the mechanisms of both structural and functional changes due to aging are still largely unclear, and there is an urgent need for in vivo characterization as to how small vessel ages over the life course in both male and female adults. Although MRI is able to image the structural aspects of the brain with a resolution of 1mm today, it has not yet been used to study microvascular details in humans in vivo at the in-plane resolution of 100μm or less. We have developed a means by which to modify the susceptibility of the arteries using an ultra-small-superparamagnetic-iron-oxide (USPIO) to make it possible to image both small arteries and veins with susceptibility weighted imaging (SWI) and quantitative susceptibility mapping (QSM) to see micro vessels less than 100μm. Our interest in this proposal is to bring together experts in a variety of medical and scientific areas such as MR physics, image processing and reconstruction to develop a new technique which we refer to ultra-high resolution USPIO-enhanced MR arteriogram and venogram (USPIO+-MRAV). We will take advantage of the blooming effect from the USPIO and the shift in susceptibility to create new means to image both arterioles and venules at the 50μm to 100μm level on both 3T and 7T MRI scanners. We expect to have a clinically viable method to create a “microvascular print” of the brain's angio-architecture based on 3D vascular tracking to assess micro-vessel topology and distribution that are not available on conventional imaging. We will develop quantitative measures of vascular density and capillary density to evaluate age-related changes in a cohort of healthy volunteers aged from 18 to 85 years. If successful, this innovative technology is expected to provide fundamental insights on how age-related microvascular alteration is detected and interpreted with in vivo brain imaging.