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）： 心脏病和中风主要是由动脉狭窄引起的。自 20 世纪 50 年代以来，X 射线血管造影一直是诊断动脉狭窄是否存在及其严重程度的主要方法。虽然 X 射线血管造影非常有用，但它是侵入性的，并且通常需要大剂量的肾毒性造影剂。我们开发了一种新的 MRI 技术，可以无创且无需造影剂地生成类似于 X 射线血管造影的电影影片。该技术涉及对众所周知的稳态自由进动 (SSFP) MRI 脉冲序列的特定更改。这项新技术，我们称之为“动态磁共振选择性血管造影”（DMRSA），涉及在移动的血液中穿过空间切片时激发质子，同时获取二维投影图像，从而可以直接可视化血液填充远端脉管系统及其分支时的情况。该技术的效率本质上是高的，因为激发和成像是同时进行的，并且因为当血液流过激发切片时新的旋转被连续地“泵入”远端脉管系统。图像以电影（电影）格式采集，以便直接可视化脉动血流。与侵入性血管造影一样，DMRSA 允许选择性地检查特定血管。我们显示的初步数据表明，血液在激励切片外行进 16 厘米后可以可视化，并且可以直接观察到分支血管的暂时充盈。我们表明，我们已经对基本物理原理有了足够的理解，足以允许我们修改基本 DMRSA 脉冲序列，从而消除我们早期实现该技术的伪影特征。我们展示了患者的示例图像，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。我们展示的大型动物数据强烈表明 DMRSA 可用于无创地确定动脉狭窄的功能意义。根据我们的初步数据，我们相信该技术具有广泛的潜在应用。我们建议优化 DMRSA 图像质量（目标 1），检验动脉狭窄的功能意义可以通过比较药物应激下与休息时的血管充盈距离来确定的假设（目标 2），并评估 DMRSA 无创检测冠状动脉疾病的能力（目标 3）。