| Autor: |
T Q, Li, A, Kastrup, M E, Moseley, G H, Glover |
| Rok vydání: |
2000 |
| Předmět: |
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| Zdroj: |
Journal of magnetic resonance imaging : JMRI. 12(5) |
| ISSN: |
1053-1807 |
| Popis: |
The effect of changes in baseline regional cerebral blood flow (rCBF) values on the cerebral blood flow response during neuronal activation was studied with functional magnetic resonance imaging (fMRI). Using a breath-holding challenge as a hypercapnic stimulus, rCBF alterations during photic stimulation under normo- and hypercapnia were determined in nine volunteers. With breath-holding, baseline rCBF in areas corresponding to the visual cortex significantly increased from 54 +/- 5 ml/100 g/min to 85 +/- 9 ml/100 g/min (P0.001). Despite this significant change in baseline flow values, the rCBF increase during visual stimulation was very similar under normo- and hypercapnic conditions (28 +/- 8 ml/100 g/min versus 26 +/- 8 ml/100 g/min, respectively). This study supports the notion that within wide physiologic variations, task-induced cerebral blood flow changes are independent of baseline rCBF values. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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