scholarly journals Surgical Results in Patients with Unruptured Asymptomatic Cerebral Aneurysms: Significance of Evaluation of Neuropsychological Function, Magnetic Resonance Images and Cerebral Blood Flow

2006 ◽  
Vol 34 (6) ◽  
pp. 434-439
Author(s):  
Yoshiaki KUMON ◽  
Hideaki WATANABE ◽  
Keiji IGASE ◽  
Shigeyuki NAGATO ◽  
Shinya FUKUMOTO ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Magnetic Resonance ◽  
Cerebral Aneurysms ◽  
Magnetic Resonance Images ◽  
Surgical Results ◽  
Neuropsychological Function

Cerebral blood flow velocity underestimates cerebral blood flow during modest hypercapnia and hypocapnia

2014 ◽  
Vol 117 (10) ◽  
pp. 1090-1096 ◽  
Author(s):  
Nicole S. Coverdale ◽  
Joseph S. Gati ◽  
Oksana Opalevych ◽  
Amanda Perrotta ◽  
J. Kevin Shoemaker
Keyword(s):  
Carbon Dioxide ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Magnetic Resonance ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Cerebral Blood Flow Velocity ◽  
Intraclass Correlation ◽  
Magnetic Resonance Images ◽  
Carbon Dioxide Partial Pressure

To establish the accuracy of transcranial Doppler ultrasound (TCD) measures of middle cerebral artery (MCA) cerebral blood flow velocity (CBFV) as a surrogate of cerebral blood flow (CBF) during hypercapnia (HC) and hypocapnia (HO), we examined whether the cross-sectional area (CSA) of the MCA changed during HC or HO and whether TCD-based estimates of CBFV were equivalent to estimates from phase contrast (PC) magnetic resonance imaging. MCA CSA was measured from 3T magnetic resonance images during baseline, HO (hyperventilation at 30 breaths/min), and HC (6% carbon dioxide). PC and TCD measures of CBFV were measured during these protocols on separate days. CSA and TCD CBFV were used to calculate CBF. During HC, CSA increased from 5.6 ± 0.8 to 6.5 ± 1.0 mm2 ( P < 0.001, n = 13), while end-tidal carbon dioxide partial pressure (PetCO2) increased from 37 ± 3 to 46 ± 5 Torr ( P < 0.001). During HO, CSA decreased from 5.8 ± 0.9 to 5.3 ± 0.9 mm2 ( P < 0.001, n = 15), while PetCO2 decreased from 36 ± 4 to 23 ± 3 Torr ( P < 0.001). CBFVs during baseline, HO, and HC were compared between PC and TCD, and the intraclass correlation coefficient was 0.83 ( P < 0.001). The relative increase from baseline was 18 ± 8% greater ( P < 0.001) for CBF than TCD CBFV during HC, and the relative decrease of CBF during HO was 7 ± 4% greater than the change in TCD CBFV ( P < 0.001). These findings challenge the assumption that the CSA of the MCA does not change over modest changes in PetCO2.

scholarly journals 19F Magnetic Resonance Imaging of Cerebral Blood Flow with 0.4-cc Resolution

1994 ◽  
Vol 14 (4) ◽  
pp. 656-663 ◽  
Author(s):  
J. Pekar ◽  
L. Ligeti ◽  
T. Sinnwell ◽  
C. T. W. Moonen ◽  
J. A. Frank ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Standard Deviation ◽  
Magnetic Resonance ◽  
Imaging Techniques ◽  
Magnetic Resonance Images ◽  
Repeated Measurements ◽  
Resonance Imaging ◽  
Average Standard Deviation

19F magnetic resonance imaging techniques were used to determine “wash-in” and “wash-out” curves of the inert, diffusible gas CHF3 from 0.4-cc voxels in the cat brain, and mass spectrometer gas detection was used to determine the CHF3 concentration in expired air. These two sets of data were used to calculate cerebral blood flow values in the 0.4-cc voxels, and the blood flow images were registered with high-resolution 1H magnetic resonance images. Data were collected both during the wash-in and wash-out phases of the experiment, but the two sets of data were analyzed separately to obtain independent estimates of the blood flow during the two phases, i.e., Qin and Qout. Repeated determinations of cerebral blood flow images were performed in individual animals, and the entire protocol was repeated on five different animals. The average values of Qin and Qout for a typical 0.4-cc voxel in the parietal cortex were 83 ml 100 g−1 min−1 and 72 ml 100 g−1 min−1, respectively. Monte Carlo calculations utilizing the noise in the 19F NMR signal from this voxel predict an average standard deviation for Qin and Qout of ± 10%. The average standard deviation for repeated measurements (in the same animal) of Qin and Qout in this voxel was ± 14%. We conclude that 19F magnetic resonance imaging approaches have the potential to image cerebral blood flow in humans.

Hemoglobin, hematocrit, and changes in cerebral blood flow: the Second Manifestations of ARTerial disease-Magnetic Resonance study

2015 ◽  
Vol 36 (3) ◽  
pp. 1417-1423 ◽  
Author(s):  
Pieternella H. van der Veen ◽  
Majon Muller ◽  
Koen L. Vincken ◽  
Jan Westerink ◽  
Willem P.T.M. Mali ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Magnetic Resonance ◽  
Arterial Disease ◽  
Magnetic Resonance Study

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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