Quantitative BOLD: Mapping of human cerebral deoxygenated blood volume and oxygen extraction fraction: Default state
Quantitative BOLD: Mapping of human cerebral deoxygenated blood volume and oxygen extraction fraction: Default state
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DOI：
10.1002/mrm.21108
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发表时间：
2007-01-01
影响因子：
3.3
通讯作者：
Yablonskiy, Dmitriy A.
中科院分区：
文献类型：
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作者：
He, Xiang;Yablonskiy, Dmitriy A.
自从Ogawa等人（Proc Natl Acad Sci USA 1990;87：9868-9872）基本发现了MRI中的血氧水平依赖性（BOLD）对比，大多数努力都指向动态BOLD（即，在脑活动变化期间MRI信号的时间变化）。然而，在阐明大脑休息或基线状态期间BOLD对比度的性质方面取得的进展很少，这对于理解正常人类表现很重要，因为它占了大脑巨大能量预算的大部分。这也是至关重要的破译脑血管疾病的基线状态损害的后果。本研究的目的是开发一种基于BOLD MR的方法，可以定量评价组织血流动力学参数，如血容量，脱氧血红蛋白浓度和氧提取分数（OEF）。所提出的方法，我们称之为定量BOLD（qBOLD），是基于一个MR信号模型，该模型结合了有关脑组织成分的先验知识，并考虑了来自灰质（GM）、白色物质（WM）、脑脊液（CSF）和血液的信号。自旋回波（GESSE）脉冲序列的2D梯度回波采样用于采集MRI信号。应用该方法对正常人脑基线状态下的血流动力学参数进行了估计。
Since Ogawa et al. (Proc Natl Acad Sci USA 1990;87:9868-9872) made the fundamental discovery of blood oxygenation level-dependent (BOLD) contrast in MRI, most efforts have been directed toward the study of dynamic BOLD (i.e., temporal changes in the MRI signal during changes in brain activity). However, very little progress has been made in elucidating the nature of BOLD contrast during the resting or baseline state of the brain, which is important for understanding normal human performance because it accounts for most of the enormous energy budget of the brain. It is also crucial for deciphering the consequences of baseline-state impairment by cerebral vascular diseases. The objective of this study was to develop a BOLD MR-based method that allows quantitative evaluation of tissue hemodynamic parameters, such as the blood volume, deoxyhemoglobin concentration, and oxygen extraction fraction (OEF). The proposed method, which we have termed quantitative BOLD (qBOLD), is based on an MR signal model that incorporates prior knowledge about brain tissue composition and considers signals from gray matter (GM), white matter (WM), cerebrospinal fluid (CSF), and blood. A 2D gradient-echo sampling of spin-echo (GESSE) pulse sequence is used for the acquisition of the MRI signal. The method is applied to estimate the hemodynamic parameters of the normal human brain in the baseline state.