scholarly journals Intraoperative BOLD-fMRI Cerebrovascular Reactivity Assessment

2021 ◽  
pp. 139-143
Author(s):  
Giovanni Muscas ◽  
Christiaan Hendrik Bas van Niftrik ◽  
Martina Sebök ◽  
Giuseppe Esposito ◽  
Luca Regli ◽  
...  
Keyword(s):  
Cerebrovascular Diseases ◽  
Blood Oxygenation ◽  
Cerebrovascular Reactivity ◽  
Hemodynamic State ◽  
Neurosurgical Patients ◽  
Blood Oxygenation Level ◽  
Oxygenation Level ◽  
Ischemic Cerebrovascular Diseases ◽  
Brain Gliomas ◽  
The Brain

AbstractBlood oxygenation-level dependent cerebrovascular reactivity (BOLD-CVR) has gained attention in recent years as an effective way to investigate CVR, a measure of the hemodynamic state of the brain, with high spatial and temporal resolution. An association between impaired CVR and diverse pathologies has been observed, especially in ischemic cerebrovascular diseases and brain gliomas. The ability to obtain this information intraoperatively is novel and has not been widely tested. We report our first experience with this intraoperative technique in vascular and oncologic neurosurgical patients, discuss the results of its feasibility, and the possible developments of the intraoperative employment of BOLD-CVR.

scholarly journals Hemodynamic investigation of peritumoral impaired blood oxygenation-level dependent cerebrovascular reactivity in patients with diffuse glioma

2020 ◽  
Vol 70 ◽  
pp. 50-56
Author(s):  
Giovanni Muscas ◽  
Christiaan Hendrik Bas van Niftrik ◽  
Martina Sebök ◽  
Katharina Seystahl ◽  
Marco Piccirelli ◽  
...  
Keyword(s):  
Blood Oxygenation Level Dependent ◽  
Blood Oxygenation ◽  
Cerebrovascular Reactivity ◽  
Diffuse Glioma ◽  
Blood Oxygenation Level ◽  
Oxygenation Level

Impact of baseline CO 2 on Blood-Oxygenation-Level-Dependent MRI measurements of cerebrovascular reactivity and task-evoked signal activation

2018 ◽  
Vol 49 ◽  
pp. 123-130 ◽  
Author(s):  
Christiaan Hendrik Bas van Niftrik ◽  
Marco Piccirelli ◽  
Oliver Bozinov ◽  
Nicolai Maldaner ◽  
Catherine Strittmatter ◽  
...  
Keyword(s):  
Blood Oxygenation Level Dependent ◽  
Blood Oxygenation ◽  
Cerebrovascular Reactivity ◽  
Blood Oxygenation Level ◽  
Oxygenation Level ◽  
Mri Measurements ◽  
Signal Activation ◽  
And Task

scholarly journals Assessing Cerebrovascular Reactivity in Carotid Steno-Occlusive Disease Using MRI BOLD and ASL Techniques

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Renata F. Leoni ◽  
Kelley C. Mazzetto-Betti ◽  
Afonso C. Silva ◽  
Antonio C. dos Santos ◽  
Draulio B. de Araujo ◽  
...  
Keyword(s):  
Cerebrovascular Diseases ◽  
Blood Oxygenation ◽  
Occlusive Disease ◽  
Cerebrovascular Reactivity ◽  
Vascular Regulation ◽  
Oxygenation Level ◽  
Biochemical Mechanisms ◽  
Magnetic Resonance Imaging Mri ◽  
Source Of Information ◽  
Reliable Methods

Impaired cerebrovascular reactivity (CVR), a predictive factor of imminent stroke, has been shown to be associated with carotid steno-occlusive disease. Magnetic resonance imaging (MRI) techniques, such as blood oxygenation level-dependent (BOLD) and arterial spin labeling (ASL), have emerged as promising noninvasive tools to evaluate altered CVR with whole-brain coverage, when combined with a vasoactive stimulus, such as respiratory task or injection of acetazolamide. Under normal cerebrovascular conditions, CVR has been shown to be globally and homogenously distributed between hemispheres, but with differences among cerebral regions. Such differences can be explained by anatomical specificities and different biochemical mechanisms responsible for vascular regulation. In patients with carotid steno-occlusive disease, studies have shown that MRI techniques can detect impaired CVR in brain tissue supplied by the affected artery. Moreover, resulting CVR estimations have been well correlated to those obtained with more established techniques, indicating that BOLD and ASL are robust and reliable methods to assess CVR in patients with cerebrovascular diseases. Therefore, the present paper aims to review recent studies which use BOLD and ASL to evaluate CVR, in healthy individuals and in patients with carotid steno-occlusive disease, providing a source of information regarding the obtained results and the methodological difficulties.

scholarly journals Cerebrovascular Reactivity in the Brain White Matter: Magnitude, Temporal Characteristics, and Age Effects

2013 ◽  
Vol 34 (2) ◽  
pp. 242-247 ◽  
Author(s):  
Binu P Thomas ◽  
Peiying Liu ◽  
Denise C Park ◽  
Matthias JP van Osch ◽  
Hanzhang Lu
Keyword(s):  
White Matter ◽  
Magnetic Resonance ◽  
Structural Characteristics ◽  
Blood Oxygenation ◽  
Cerebrovascular Reactivity ◽  
Tissue Ischemia ◽  
Brain White Matter ◽  
Oxygenation Level ◽  
Magnetic Resonance Imaging Mri ◽  
The Brain

White matter (WM) comprises about half of the brain and its dysfunction is implicated in many brain disorders. While structural properties in healthy and diseased WM have been extensively studied, relatively little is known about the physiology underlying these structural characteristics. Recent advances in magnetic resonance (MR) technologies provided new opportunities to better understand perfusion and microvasculature in the WM. Here, we aim to evaluate vasodilatory capacity of the WM vasculature, which is thought to be important in tissue ischemia and autoregulation. Fifteen younger and fifteen older subjects performed a CO2 inhalation task while blood-oxygenation-level-dependent (BOLD) magnetic resonance imaging (MRI) images were continuously collected. The cerebrovascular reactivity (CVR) index showed that the value of CVR in the WM (0.03±0.002%/mm Hg) was positive, but was significantly lower than that in the gray matter (GM) (0.22±0.01%/mm Hg). More strikingly, the WM response showed a temporal delay of 19±3 seconds compared with GM, which was attributed to the longer time it takes for extravascular CO2 to change. With age, WM CVR response becomes greater and faster, which is opposite to the changes seen in the GM. These data suggest that characteristics of WM CVR are different from that of GM and caution should be used when interpreting pathologic WM CVR results.

scholarly journals Static and Dynamic Functional Connectivity Analysis of Cerebrovascular Reactivity: An fMRI Study

2019 ◽  
Author(s):  
N. Lewis ◽  
H. Lu ◽  
P. Liu ◽  
X. Hou ◽  
E. Damaraju ◽  
...  
Keyword(s):  
Vascular System ◽  
Network Connectivity ◽  
Cerebrovascular Diseases ◽  
Blood Oxygenation ◽  
Cerebrovascular Reactivity ◽  
Fmri Study ◽  
Oxygenation Level ◽  
Intrinsic Connectivity Networks ◽  
The One ◽  
Cerebrovascular System

ABSTRACTThe human brain, as a finely-tuned system, needs a constant flow of oxygen to function properly. To accomplish this, the cerebrovascular system ensures a steady stream of oxygenation to brain cells. One tool that the cerebrovascular system uses is cerebrovascular reactivity (CVR), which is the system’s ability to react to vasoactive stimuli. Understanding CVR can provide unique information about cerebrovascular diseases and general brain function. CVR can be evaluated by scanning subjects with blood-oxygenation-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) while they periodically inhale room air and CO2-enriched gas, a powerful and widely-used vasodilator. Our goal is to understand the effect of vasodilation on individual intrinsic connectivity networks (ICNs), as well as how functional network connectivity (FNC) adapts to the same vasodilation. To achieve this goal, we first developed an innovative metric to measure the effect of CVR on ICNs, which contrasts to the commonly used voxel-wise CVR. Furthermore, for the first time, we studied static (sFNC) and dynamic (dFNC) FNC in the context of CVR. Our results show that network connectivity is generally weaker during vascular dilation, and these results are more pronounced in dFNC analysis. dFNC analysis reveals that participants did not return to the pre-CO2 inhalation state, suggesting that the one-minute period of room-air inhalation is not enough for the CO2 effect to fully dissipate in humans. Overall, we see new relationships between CVR and ICNs, as well as how FNC adapts to vascular system changes.

scholarly journals Time delay processing of hypercapnic fMRI allows quantitative parameterization of cerebrovascular reactivity and blood flow delays

2016 ◽  
Vol 36 (10) ◽  
pp. 1767-1779 ◽  
Author(s):  
Manus J Donahue ◽  
Megan K Strother ◽  
Kimberly P Lindsey ◽  
Lia M Hocke ◽  
Yunjie Tong ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cross Correlation ◽  
Blood Oxygenation Level Dependent ◽  
Blood Oxygenation ◽  
Intracranial Stenosis ◽  
Peak Time ◽  
Surgical Revascularization ◽  
Blood Oxygenation Level ◽  
Oxygenation Level ◽  
The Brain

Blood oxygenation level-dependent fMRI contrast depends on the volume and oxygenation of blood flowing through the circulatory system. The effects on image intensity depend temporally on the arrival of blood within a voxel, and signal can be monitored during the time course of such blood flow. It has been previously shown that the passage of global endogenous variations in blood volume and oxygenation can be tracked as blood passes through the brain by determining the strength and peak time lag of their cross-correlation with blood oxygenation level-dependent data. By manipulating blood composition using transient hypercarbia and hyperoxia, we can induce much larger oxygenation and volume changes in the blood oxygenation level-dependent signal than result from natural endogenous fluctuations. This technique was used to examine cerebrovascular parameters in healthy subjects (n = 8) and subjects with intracranial stenosis (n = 22), with a subgroup of intracranial stenosis subjects scanned before and after surgical revascularization (n = 6). The halfwidth of cross-correlation lag times in the brain was larger in IC stenosis subjects (21.21 ± 14.22 s) than in healthy control subjects (8.03 ± 3.67), p < 0.001, and was subsequently reduced in regions that co-localized with surgical revascularization. These data show that blood circulatory timing can be measured robustly and longitudinally throughout the brain using simple respiratory challenges.

scholarly journals Cerebrovascular blood oxygenation level dependent pulsatility at baseline and following acute exercise among healthy adolescents

2018 ◽  
Vol 39 (9) ◽  
pp. 1737-1749 ◽  
Author(s):  
Athena E Theyers ◽  
Benjamin I Goldstein ◽  
Arron WS Metcalfe ◽  
Andrew D Robertson ◽  
Bradley J MacIntosh
Keyword(s):  
Acute Exercise ◽  
Physiological Stress ◽  
Blood Oxygenation Level Dependent ◽  
Blood Oxygenation ◽  
Moderate Intensity ◽  
Efficient Detection ◽  
Blood Oxygenation Level ◽  
Oxygenation Level ◽  
Repetition Time ◽  
The Brain

Arterial stiffness is linked to cerebral small vessel damage and neurodegeneration, but barriers to accessing deep cerebrovascular anatomy limit our ability to assess the brain. This study describes an adaptation of a cardiac-related scrubbing method as a means of generating blood oxygenation level-dependent pulsatility maps based on the cardiac cycle. We examine BOLD pulsatility at rest, based on the non-parametric deviation from null metric, as well as changes following acute physiological stress from 20 min of moderate-intensity cycling in 45 healthy adolescents. We evaluate the influence of repetition time (TR) and echo time (TE) using simulated and multi-echo empirical data, respectively. There were tissue-specific and voxel-wise BOLD pulsatility decreases 20 min following exercise cessation. BOLD pulsatility detection was comparable over a range of TR and TE values when scan volumes were kept constant; however, short TRs (≤500 ms) and TEs (∼14 ms) acquisitions would yield the most efficient detection. Results suggest cardiac-related BOLD pulsatility may represent a robust and easily adopted method of mapping cerebrovascular pulsatility with voxel-wise resolution.

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