MR fingerprinting (MRF) perfusion imaging in cerebral vascular disease

项目概要/摘要： 缺血性中风是世界范围内的主要健康问题。在美国，它是第四大原因， 死亡和主要残疾的主要原因。据估计，超过70万美国人经历了 每年新发或复发的中风。灌注成像在中风的几乎所有阶段都起着重要的作用 以及相关的脑血管疾病。 目前，大多数临床灌注成像需要使用造影剂，例如钆（Gd）， 核磁共振然而，由于各种原因，Gd灌注MRI不能用于或未能用于10-20%的患者。 原因，如过敏反应，肾小球滤过率低，难以放置静脉输液管， 适用于快速注射，或注射时机的人为错误。因此，一种替代技术， Gd灌注在临床实践中将使大量患者受益。 动脉自旋标记（ASL）MRI允许对脑血流量（CBF）进行非造影评价。然而，在这方面， 在其当前形式中，它不能提供与通过基于造影剂灌注获得的信息等效的信息 显像这是因为CBF在卒中描绘中的价值有限。在Gd中最有用的参数- 灌注是Tmax或推注到达时间（BAT），但它们不能用当前ASL方法可靠地测量。 本申请将开发一种新的非造影剂灌注技术，应用MR的新原理 指纹识别（MRF）到ASL。这种技术的主要优点是它允许同时估计 CBF、BAT、T1、B1+、血容量和动脉行程时间等六个参数。目标1是 MRF-ASL MRI技术的发展。我们将开发MRF-ASL序列时序， 灌注参数的编码。我们还将开发k空间欠采样策略，以获得高 空间分辨率灌注成像而不增加回波链长度。我们将对 使用基于Gd的灌注MRI技术。该项目的目标2将开发基于云的ASL分析 一个可以为研究人员和临床医生提供免安装、独立于操作系统的平台 ASL分析工具（MRF-ASL以及所有其他类型的ASL数据）。我们在约翰霍普金斯的临床团队 对亚急性中风的机制和治疗研究有着长期的兴趣。因此，目标3 目前的项目是证明该技术在亚急性卒中中的初步临床应用。 最后，应该强调的是，虽然本项目的重点是其临床应用， 虽然脑血管疾病，但开发的方法在其他脑疾病中也具有重要的实用性，例如 神经变性疾病（例如阿尔茨海默氏病、帕金森氏病、亨廷顿氏病）、精神疾病（例如阿尔茨海默氏病、帕金森氏病、亨廷顿氏病）、神经系统疾病（例如阿尔茨海默氏病、帕金森氏病、亨廷顿氏病）、神经系统疾病（例如阿尔茨海默氏病、帕金森氏病、亨廷顿氏病）、神经系统疾病（例如帕金森氏病、亨廷顿氏病）、神经系统疾病（例如阿尔茨海默氏病、亨廷顿氏病、亨廷顿氏病）、神经系统疾病（例如阿尔茨海默氏病、帕金森氏病、亨廷顿氏病、亨廷顿氏病）、神经系统疾病（例如阿尔茨海默氏病、帕金森氏病、亨廷顿氏病、亨廷顿氏病）、神经系统疾病（例如阿尔茨海默氏病、帕金森氏病、亨廷顿氏病、亨廷顿氏 精神分裂症、抑郁症、自闭症、ADHD）和肿瘤（原发性和转移性脑肿瘤）。因此， 这项技术有望产生广泛的临床影响。

Project Summary/Abstract: Ischemic stroke is a major health problem worldwide. In the United States, it is the fourth leading cause of death and the leading cause of major disability. It is estimated that more than 700,000 Americans experience new or recurrent stroke each year. Perfusion imaging plays an important role in virtually all stages of stroke and related cerebrovascular diseases. At present, most clinical perfusion imaging requires the use of contrast agents, e.g. gadolinium (Gd) in MRI. However, Gd perfusion MRI cannot be used or fails to be used in 10-20% of patients, due to a variety of reasons, such as allergic reactions, low glomerular filtration rate, difficulties in placing an intravenous line that is suitable for a rapid injection, or human errors in the timing of injection. Therefore, an alternative technique to Gd-perfusion will benefit a substantial number of patients in clinical practice. Arterial Spin Labeling (ASL) MRI allows for non-contrast evaluation of cerebral blood flow (CBF). However, in its current form, it cannot provide information equivalent to that obtained by contrast-agent-based perfusion imaging. This is because CBF is of limited value in stroke delineation. The most useful parameter in Gd- perfusion is Tmax or bolus-arrive-time (BAT), yet they cannot be measured reliably with current ASL methods. This application will develop a novel non-contrast perfusion technique that applies a new principle of MR fingerprinting (MRF) to ASL. The major strength of this technique is that it allows for simultaneous estimations of six parameters, CBF, BAT, T1, B1+, blood volume, and arterial travel time, in a single scan. Aim 1 is the development of the MRF-ASL MRI technique. We will develop MRF-ASL sequence timing for efficient encoding of perfusion parameters. We will also develop k-space undersampling strategies to obtain high spatial resolution perfusion imaging without increasing echo-train length. We will conduct validation of the technique using Gd-based perfusion MRI. Aim 2 of this project will develop a cloud-based ASL analysis platform that can provide researchers and clinicians with an installation-free, operating-system independent tool for ASL analysis (of MRF-ASL as well as all other types of ASL data). Our clinical team at Johns Hopkins has a long-standing interest in mechanistic and therapeutic studies of sub-acute stroke. Therefore, Aim 3 of the present project is to demonstrate the initial clinical utility of the technique in sub-acute stroke. Finally, it should be emphasized that, although the present project focuses on its clinical applications in cerebrovascular diseases, the method developed also has important utility in other brain diseases, such neurodegenerative diseases (e.g. Alzheimer’s, Parkinson’s, Huntington’s diseases), psychiatric diseases (e.g. schizophrenia, depression, autism, ADHD), and tumor (primary and metastatic brain tumor). Thus, this technique is expected to have a broad clinical impact.