scholarly journals Interdependence of Regional and Global Cerebral Blood Flow during Visual Stimulation: An O-15-Butanol Positron Emission Tomography Study

2001 ◽  
Vol 21 (6) ◽  
pp. 664-670 ◽  
Author(s):  
Lars J. Kemna ◽  
Stefan Posse ◽  
Lutz Tellmann ◽  
Thomas Schmitz ◽  
Hans Herzog
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Visual Stimulation ◽  
Emission Tomography ◽  
Global Flow ◽  
Positron Emission ◽  
Global Cerebral Blood Flow ◽  
Flow Changes ◽  
O 15

The authors investigated the influence of variations in global cerebral blood flow (gCBF) on regional flow changes during visual stimulation. Global flow was varied using different end-expiratory CO2 values (Petco2) between 20 and 70 mm Hg. Visual stimulation was performed with a red LED-array flashing at 8 Hz. Blood flow was measured with O-15-butanol, continuous arterial blood sampling, and positron emission tomography (PET). Global flow changes surpassed the published values of O-15-H2O studies, better fitting the results of the inert gas technique (gCBF at 20, 40, and 70 mm Hg Petco2 ± SD was 31 ± 4, 48 ± 13, and 160 ± 50 mL 100 g−1 min−1, respectively). The relation between Petco2 and CBF in the current study was best described by an exponential rather than a linear function. At low Petco2, the activation-induced flow changes are moderately damped, whereas at high Petco2, they are nearly lost (ΔCBF (±SD): 52% ± 25%, 68% ± 22%, 16% ± 25% at Petco2 = 20, 40, 70 mm Hg, respectively).

scholarly journals Phase contrast mapping MRI measurements of global cerebral blood flow across different perfusion states – A direct comparison with 15O-H2O positron emission tomography using a hybrid PET/MR system

2018 ◽  
Vol 39 (12) ◽  
pp. 2368-2378 ◽  
Author(s):  
Oriol Puig ◽  
Mark B Vestergaard ◽  
Ulrich Lindberg ◽  
Adam E Hansen ◽  
Annette Ulrich ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Strong Correlation ◽  
Phase Contrast ◽  
Young Male ◽  
Emission Tomography ◽  
Easy Access ◽  
Positron Emission ◽  
Global Cerebral Blood Flow

Phase-contrast mapping (PCM) magnetic resonance imaging (MRI) provides easy-access non-invasive quantification of global cerebral blood flow (gCBF) but its accuracy in altered perfusion states is not established. We aimed to compare paired PCM MRI and 15O-H2O positron emission tomography (PET) measurements of gCBF in different perfusion states in a single scanning session. Duplicate combined gCBF PCM-MRI and 15O-H2O PET measurements were performed in the resting condition, during hyperventilation and after acetazolamide administration (post-ACZ) using a 3T hybrid PET/MR system. A total of 62 paired gCBF measurements were acquired in 14 healthy young male volunteers. Average gCBF in resting state measured by PCM-MRI and 15O-H2O PET were 58.5 ± 10.7 and 38.6 ± 5.7 mL/100 g/min, respectively, during hyperventilation 33 ± 8.6 and 24.7 ± 5.8 mL/100 g/min, respectively, and post-ACZ 89.6 ± 27.1 and 57.3 ± 9.6 mL/100 g/min, respectively. On average, gCBF measured by PCM-MRI was 49% higher compared to 15O-H2O PET. A strong correlation between the two methods across all states was observed (R2 = 0.72, p < 0.001). Bland–Altman analysis suggested a perfusion dependent relative bias resulting in higher relative difference at higher CBF values. In conclusion, measurements of gCBF by PCM-MRI in healthy volunteers show a strong correlation with 15O-H2O PET, but are associated with a large and non-linear perfusion-dependent difference.

scholarly journals Comparison of global cerebral blood flow measured by phase-contrast mapping MRI with 15 O-H2 O positron emission tomography

2016 ◽  
Vol 45 (3) ◽  
pp. 692-699 ◽  
Author(s):  
Mark Bitsch Vestergaard ◽  
Ulrich Lindberg ◽  
Niels Jacob Aachmann-Andersen ◽  
Kristian Lisbjerg ◽  
Søren Just Christensen ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Phase Contrast ◽  
Emission Tomography ◽  
Positron Emission ◽  
Global Cerebral Blood Flow

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 Absolute Cerebral Blood Flow and Blood Volume Measured by Magnetic Resonance Imaging Bolus Tracking: Comparison with Positron Emission Tomography Values

1998 ◽  
Vol 18 (4) ◽  
pp. 425-432 ◽  
Author(s):  
Leif Østergaard ◽  
Donald F. Smith ◽  
Peter Vestergaard-Poulsen ◽  
SørenB. Hansen ◽  
Antony D. Gee ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Magnetic Resonance ◽  
Blood Volume ◽  
Emission Tomography ◽  
Resonance Imaging ◽  
Positron Emission ◽  
O 15

The authors determined cerebral blood flow (CBF) with magnetic resonance imaging (MRI) of contrast agent bolus passage and compared the results with those obtained by O-15 labeled water (H215O) and positron emission tomography (PET). Six pigs were examined by MRI and PET under normo- and hypercapnic conditions. After dose normalization and introduction of an empirical constant ΦGd, absolute regional CBF was calculated from MRI. The spatial resolution and the signal-to-noise ratio of CBF measurements by MRI were better than by the H215O-PET protocol. Magnetic resonance imaging cerebral blood volume (CBV) estimates obtained using this normalization constant correlated well with values obtained by O-15 labeled carbonmonooxide (C15O) PET. However, PET CBV values were approximately 2.5 times larger than absolute MRI CBV values, supporting the hypothesized sensitivity of MRI to small vessels.

[O-15]H2O Positron Emission Tomography Determination of Cerebral Blood Flow Reserve after Intravenous Acetazolamide during Balloon Test Occlusion of the Internal Carotid Artery

1998 ◽  
Vol 4 (1) ◽  
pp. 57-62 ◽  
Author(s):  
K.J. Murphy ◽  
J.P. Deveikis ◽  
J.A. Brunberg ◽  
D.A. Jamadar ◽  
K.A. Frey
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Carotid Artery ◽  
Internal Carotid ◽  
Balloon Occlusion ◽  
Emission Tomography ◽  
Balloon Test Occlusion ◽  
Positron Emission ◽  
O 15

The purpose of this paper was to evaluate the effects of acetazolamide on cerebral blood flow (CBF) measured by [O-15] H2O positron emission tomography (PET) during balloon test occlusion (BTO) of the internal carotid artery (ICA). [O-15] H2O PET cerebral blood flow studies were completed in 20 patients undergoing BTO. CBF determinations were obtained without carotid occlusion as a baseline, following balloon occlusion, and as a third scan with balloon occlusion after an intravenous acetazolamide bolus. The balloon was left deflated between scans, and was only inflated immediately before and during the 90 second period of time needed for CBF determination. Significance was determined at the P<0.05 level. Two of twenty studies were technical failures. Prior to acetazolamide there was a significant decrease in CBF (P<0.0007) ipsilateral to the occlusion. After acetazolamide administration there was no statistically significant change in flow on the occluded side (P<0.3047); however, there was a significant increase in cerebral blood flow (P<0.0002) on the non-occluded side. In this patient population, there was no acetazolamide-induced CBF decompensation (steal) phenomenon or haemodynamically significant risk in CBF ipsilateral to the occlusion.

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