MEASUREMENT OF CBF AND CBV IN HUMANS USING WASHOUT OF HYPEROXIC CONTRAST

使用高氧对比冲洗法测量人体 CBF 和 CBV

• 批准号: 8361982
• 负责人: David Pilkinton
• 金额: $ 2.31万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-06-01 至 2012-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8361982
• 关键词: Arteries; Blood Volume; Blood flow; Brain; Breathing; Cerebrovascular Circulation; Cerebrum; Exhibits; Funding; Grant; Human; Hyperoxia; Image; Magnetic Resonance; Magnetic Resonance Imaging; Measurement; Measures; Molecular; National Center for Research Resources; Oxygen; Plasma; Predisposition; Principal Investigator; Relative (related person); Research; Research Infrastructure; Resources; Signal Transduction; Source; Time; United States National Institutes of Health; Weight; cost; experience; feeding; hemodynamics; optical imaging; theories

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. It is typically assumed that hyperoxia substantially alters the hemodynamics of the brain, confounding attempts to measure hemodynamic quantities with hyperoxic contrast. However, studies have recently shown that cerebral blood flow (CBF) experiences only a small (<4%) reduction upon breathing low to moderate oxygen concentrations (FiO2d0.5) -- flow changes that are too low to be produce signal changes that can be detected by typical BOLD T2*-weighted EPI. Hyperoxic contrast has been shown to exhibit fast washout times, which make feasible the accurate measurements of dynamic parameters  such as blood flow -- using hyperoxic contrast. We have recently observed substantial negative contrast enhancement in T2*-weighted images near arteries in the brain that we believe is due to excess dissolved paramagnetic molecular oxygen in the plasma. This negative contrast enhancement provides the means to infer the relative excess oxygen content in the arteries feeding the brain and thereby measure an arterial input function (AIF) necessary for quantitative flow values. In addition, hyperoxic contrast can be used to measure cerebral blood volume (CBV) using hyperoxic contrast enhancement measured during steady-state. We are currently investigating the accuracy of measurements of CBV and CBF made dynamically during the washout of hyperoxic contrast using indicator-dilution theory in a manner akin to dynamic susceptibility contrast MRI (DSC-MRI)measurements.

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 通常认为，高氧大大改变了大脑的血液动力学，混淆了 尝试用高氧造影剂测量血液动力学量。 然而研究 最近表明，脑血流量（CBF）仅经历小的（<4%）减少， 呼吸低至中等氧气浓度（FiO2d0.5）-流量变化太低，无法 产生的信号变化可以通过典型的BOLD T2* 加权EPI检测到。 高氧造影剂 已经显示出快速的冲洗时间，这使得精确测量 动态参数  比如血流--使用高氧造影剂。 我们最近观察到 在T2* 加权图像中，我们发现脑内动脉附近有明显的负对比度增强， 认为是由于血浆中过量溶解的顺磁性分子氧。 这种负面 对比增强提供了推断动脉中相对过量氧含量的手段 从而测量定量血流所需的动脉输入功能（AIF 价值观 此外，高氧造影剂可用于测量脑血容量（CBV）， 在稳态期间测量的高氧对比度增强。 我们目前正在调查 高氧洗脱期间动态测量CBV和CBF的准确性 以类似于动态磁化率对比MRI的方式使用指示剂稀释理论进行对比 （DSC-MRI）测量。