Dynamic Magnetic Resonance Selective Angiography

动态磁共振选择性血管造影

• 批准号: 7032281
• 负责人: ROBERT M JUDD
• 金额: $ 37.6万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-01 至 2008-03-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7032281
• 关键词: angiography; artery stenosis; bioimaging /biomedical imaging; clinical research; coronary disorder; diagnosis design /evaluation; dogs; heart disorder diagnosis; heart imaging /visualization /scanning; human subject; image enhancement; magnetic resonance imaging; noninvasive diagnosis; ultrasound blood flow measurement

DESCRIPTION (provided by applicant): Heart disease and stroke are caused primarily by arterial stenoses. Since the 1950's X-ray angiography has been the primary method of diagnosing the presence and significance of arterial stenoses. While extremely useful, x-ray angiography is invasive and often requires large doses of nephrotoxic contrast agents. We have developed a new MRI technique which produces cine movie analogous to those of x-ray angiography noninvasively and without a contrast agent. The technique involves specific changes to the well-known steady state free precession (SSFP) MRI pulse sequence. This new technique, which we term "Dynamic Magnetic Resonance Selective Angiography" (DMRSA), involves exciting protons within moving blood as they travel through a slice in space and, simultaneously, acquiring two-dimensional projection images which allow direct visualization of the blood as it fills the distal vasculature and its branches. The efficiency of the technique is intrinsically high both because excitation and imaging are performed simultaneously and because new spins are continuously "pumped" into the distal vasculature as blood flows through the excitation slice. The images are acquired in cine (movie) format such that pulsatile blood flow is directly visualized. Like invasive angiography, DMRSA allows specific blood vessels to be selectively interrogated. We show preliminary data demonstrating that blood can be visualized after traveling up to 16 cm outside the excitation slice, and that temporal filling of branch vessels is directly observed. We show that we have developed an understanding of the underlying physical principles sufficient to allow us to modify the basic DMRSA pulse sequence in such a way that artifacts characteristic of our early implementations of the technique are eliminated. We show example images in a patient in which the aorta and renal arteries are visualized in the same manner as in x-ray angiography. We show large animal data strongly suggesting that that DMRSA can be used to noninvasively determine the functional significance of arterial stenoses. Based on our preliminary data we believe this technique has wide potential application. We propose to optimize DMRSA image quality (Aim 1), to test the hypothesis that the functional significance of arterial stenoses can be determined by comparing vessel filling distances under pharmacologic stress to those at rest (Aim 2), and to evaluate the ability of DMRSA to non-invasively detect coronary artery disease (Aim 3).

描述（由申请人提供）： 心脏病和中风主要由动脉狭窄引起。自1950年代以来，X射线血管造影是诊断动脉狭窄的存在和意义的主要方法。 X射线血管造影虽然非常有用，但却具有侵入性，通常需要大剂量的肾毒性对比剂。我们已经开发了一种新的MRI技术，该技术产生了类似于X射线血管造影术的Cine电影，没有造影剂。该技术涉及对众所周知的稳态无稳态进动（SSFP）MRI脉冲序列的特定变化。我们称这种新技术为“动态磁共振选择性血管造影”（DMRSA），涉及令人兴奋的质子在移动的血液中穿过太空中的片段，同时，同时获得了二维投影图像，从而使血液直接可视化，从而填充远端血管及其分支。该技术的效率在本质上都很高，因为激发和成像是同时执行的，并且由于血液通过激发切片流动时，新的旋转被连续地“泵送”到远端脉管系统中。这些图像以电影（电影）格式获取，以使脉冲血流直接可视化。像侵入性血管造影一样，DMRSA允许对特定的血管进行选择性审查。我们显示的初步数据表明，在激发切片外达16厘米后，可以看到血液，并且直接观察到分支血管的时间填充。我们表明，我们已经对基本的物理原理有了足够的理解，可以使我们修改基本的DMRSA脉冲序列，从而消除了我们早期实现该技术的伪像特征。我们在患者中显示了示例图像，其中主动脉和肾动脉以与X射线血管造影相同的方式可视化。我们显示了大量动物数据，表明DMRSA可用于非侵入性地确定动脉伸卵的功能意义。根据我们的初步数据，我们认为该技术具有广泛的潜在应用。我们建议优化DMRSA图像质量（AIM 1），以检验以下假设：可以通过将药理学应力下的血管填充距离与静止人员进行比较（AI​​M 2），并评估DMRSA与非耐酸检测冠状动脉疾病（AIM AIM 3）来确定动脉伸展的功能意义。