scholarly journals Cortical layer-dependent dynamic blood oxygenation, cerebral blood flow and cerebral blood volume responses during visual stimulation

NeuroImage ◽  
2008 ◽  
Vol 43 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Tao Jin ◽  
Seong-Gi Kim
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Visual Stimulation ◽  
Cortical Layer ◽  
Blood Oxygenation

scholarly journals Changes in Human Regional Cerebral Blood Flow and Cerebral Blood Volume during Visual Stimulation Measured by Positron Emission Tomography

2001 ◽  
Vol 21 (5) ◽  
pp. 608-612 ◽  
Author(s):  
Hiroshi Ito ◽  
Kazuhiro Takahashi ◽  
Jun Hatazawa ◽  
Seong-Gi Kim ◽  
Iwao Kanno
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Visual Stimulation ◽  
Emission Tomography ◽  
Neural Activation ◽  
Positron Emission ◽  
Stimulation Of

The hemodynamic mechanism of increase in cerebral blood flow (CBF) during neural activation has not been elucidated in humans. In the current study, changes in both regional CBF and cerebral blood volume (CBV) during visual stimulation in humans were investigated. Cerebral blood flow and CBV were measured by positron emission tomography using H215O and 11CO, respectively, at rest and during 2-Hz and 8-Hz photic flicker stimulation in each of 10 subjects. Changes in CBF in the primary visual cortex were 16% ± 16% and 68% ± 20% for the visual stimulation of 2 Hz and 8 Hz, respectively. The changes in CBV were 10% ± 13% and 21% ± 5% for 2-Hz and 8-Hz stimulation, respectively. Significant differences between changes in CBF and CBV were observed for visual stimulation of 8 Hz. The relation between CBF and CBV values during rest and visual stimulation was CBV = 0.88CBF0.30. This indicates that when the increase in CBF during neural activation is great, that increase is caused primarily by the increase in vascular blood velocity rather than by the increase in CBV. This observation is consistent with reported findings obtained during hypercapnia.

scholarly journals Temporal Dynamics and Spatial Specificity of Arterial and Venous Blood Volume Changes during Visual Stimulation: Implication for Bold Quantification

2010 ◽  
Vol 31 (5) ◽  
pp. 1211-1222 ◽  
Author(s):  
Tae Kim ◽  
Seong-Gi Kim
Keyword(s):  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Temporal Dynamics ◽  
Visual Stimulation ◽  
Magnetization Transfer ◽  
Venous Blood ◽  
Cortical Layer ◽  
Blood Oxygenation ◽  
Order Of Magnitude ◽  
The Difference

Determination of compartment-specific cerebral blood volume ( CBV) changes is important for understanding neurovascular physiology and quantifying blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI). In isoflurane-anesthetized cats, we measured the spatiotemporal responses of arterial CBV ( CBVa) and total CBV ( CBVt) induced by a 40-second visual stimulation, using magnetization transfer (MT)-varied BOLD and contrast-agent fMRI techniques at 9.4 T. To determine the venous CBV ( CBVv) change, we calculated the difference between CBVt and CBVa changes. The dynamic response of CBVa was an order of magnitude faster than that of CBVv, while the magnitude of change under steady-state conditions was similar between the two. Following stimulation offset, Δ CBVa showed small poststimulus undershoots, while Δ CBVv slowly returned to baseline. The largest CBVa and CBVt response occurred after 10 seconds of simulation in cortical layer 4, which we identified as the stripe of Gennari by T1-weighted MRI. The CBVv response, however, was not specific across the cortical layers during the entire stimulation period. Our data indicate that rapid, more-specific arterial vasodilation is followed by slow, less-specific venous dilation. Our finding implies that the contribution of CBVv changes to BOLD signals is significant for long, but not short, stimulation periods.

scholarly journals Hemodynamic Changes after Visual Stimulation and Breath Holding Provide Evidence for an Uncoupling of Cerebral Blood Flow and Volume from Oxygen Metabolism

2008 ◽  
Vol 29 (1) ◽  
pp. 176-185 ◽  
Author(s):  
Manus J Donahue ◽  
Robert D Stevens ◽  
Michiel de Boorder ◽  
James J Pekar ◽  
Jeroen Hendrikse ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Cerebral Blood Volume ◽  
Visual Stimulation ◽  
Functional Neuroimaging ◽  
Oxygen Metabolism ◽  
Blood Oxygenation ◽  
Breath Holding ◽  
Breath Hold ◽  
Bold Signal

Functional neuroimaging is most commonly performed using the blood-oxygenation-level-dependent (BOLD) approach, which is sensitive to changes in cerebral blood flow (CBF), cerebral blood volume (CBV), and the cerebral metabolic rate of oxygen (CMRO2). However, the precise mechanism by which neuronal activity elicits a hemodynamic response remains controversial. Here, visual stimulation (14 secs flashing checkerboard) and breath-hold (4 secs exhale + 14 secs breath hold) experiments were performed in alternating sequence on healthy volunteers using BOLD, CBV-weighted, and CBF-weighted fMRI. After visual stimulation, the BOLD signal persisted for 33 ± 5 secs (n = 9) and was biphasic with a negative component (undershoot), whereas CBV and CBF returned to baseline without an undershoot at 20 ± 5 and 20 ± 3 secs, respectively. After breath hold, the BOLD signal returned to baseline (23 ±7 secs) at the same time ( P < 0.05) as CBV (21 ± 6 secs) and CBF (18 ±3 secs), without a poststimulus undershoot. These data suggest that the BOLD undershoot after visual activation reflects a persistent increase in CMRO2. These observations support the view that CBV and CBF responses elicited by neuronal activation are not necessarily coupled to local tissue metabolism.

Hyperacute Stroke: Simultaneous Measurement of Relative Cerebral Blood Volume, Relative Cerebral Blood Flow, and Mean Tissue Transit Time

Radiology ◽  
1999 ◽  
Vol 210 (2) ◽  
pp. 519-527 ◽  
Author(s):  
A. Gregory Sorensen ◽  
William A. Copen ◽  
Leif Østergaard ◽  
Ferdinando S. Buonanno ◽  
R. Gilberto Gonzalez ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Blood Volume ◽  
Transit Time ◽  
Simultaneous Measurement ◽  
Cerebral Blood Volume ◽  
Hyperacute Stroke ◽  
Relative Cerebral Blood Volume

scholarly journals Effects of Acetazolamide on Cerebral Blood Flow, Blood Volume, and Oxygen Metabolism: A Positron Emission Tomography Study with Healthy Volunteers

2001 ◽  
Vol 21 (12) ◽  
pp. 1472-1479 ◽  
Author(s):  
Hidehiko Okazawa ◽  
Hiroshi Yamauchi ◽  
Kanji Sugimoto ◽  
Hiroshi Toyoda ◽  
Yoshihiko Kishibe ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Metabolic Rate ◽  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Capillary Blood ◽  
Emission Tomography ◽  
Positron Emission ◽  
Capillary Blood Volume

To evaluate changes in cerebral hemodynamics and metabolism induced by acetazolamide in healthy subjects, positron emission tomography studies for measurement of cerebral perfusion and oxygen consumption were performed. Sixteen healthy volunteers underwent positron emission tomography studies with15O-gas and water before and after intravenous administration of acetazolamide. Dynamic positron emission tomography data were acquired after bolus injection of H215O and bolus inhalation of15O2. Cerebral blood flow, metabolic rate of oxygen, and arterial-to-capillary blood volume images were calculated using the three-weighted integral method. The images of cerebral blood volume were calculated using the bolus inhalation technique of C15O. The scans for cerebral blood flow and volume and metabolic rate of oxygen after acetazolamide challenge were performed at 10, 20, and 30 minutes after drug injection. The parametric images obtained under the two conditions at baseline and after acetazolamide administration were compared. The global and regional values for cerebral blood flow and volume and arterial-to-capillary blood volume increased significantly after acetazolamide administration compared with the baseline condition, whereas no difference in metabolic rate of oxygen was observed. Acetazolamide-induced increases in both blood flow and volume in the normal brain occurred as a vasodilatory reaction of functioning vessels. The increase in arterial-to-capillary blood volume made the major contribution to the cerebral blood volume increase, indicating that the raise in cerebral blood flow during the acetazolamide challenge is closely related to arterial-to-capillary vasomotor responsiveness.

Early changes measured by magnetic resonance imaging in cerebral blood flow, blood volume, and blood-brain barrier permeability following dexamethasone treatment in patients with brain tumors

1999 ◽  
Vol 90 (2) ◽  
pp. 300-305 ◽  
Author(s):  
Leif Østergaard ◽  
Fred H. Hochberg ◽  
James D. Rabinov ◽  
A. Gregory Sorensen ◽  
Michael Lev ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Magnetic Resonance ◽  
Brain Tumors ◽  
Mr Imaging ◽  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Clinical Effects ◽  
Content Type ◽  
Fine Print

Object. In this study the authors assessed the early changes in brain tumor physiology associated with glucocorticoid administration. Glucocorticoids have a dramatic effect on symptoms in patients with brain tumors over a time scale ranging from minutes to a few hours. Previous studies have indicated that glucocorticoids may act either by decreasing cerebral blood volume (CBV) or blood-tumor barrier (BTB) permeability and thereby the degree of vasogenic edema.Methods. Using magnetic resonance (MR) imaging, the authors examined the acute changes in CBV, cerebral blood flow (CBF), and BTB permeability to gadolinium-diethylenetriamine pentaacetic acid after administration of dexamethasone in six patients with brain tumors. In patients with acute decreases in BTB permeability after dexamethasone administration, changes in the degree of edema were assessed using the apparent diffusion coefficient of water.Conclusions. Dexamethasone was found to cause a dramatic decrease in BTB permeability and regional CBV but no significant changes in CBF or the degree of edema. The authors found that MR imaging provides a powerful tool for investigating the pathophysiological changes associated with the clinical effects of glucocorticoids.

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