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Functional magnetic resonance imaging (fMRI) was used to investigate the changes in blood oxygenation level dependent (BOLD) signal, cerebral blood flow (CBF) and cerebral metabolic rate of oxygen consumption (CMR(O(2))) accompanying neuronal inhibition. Eight healthy volunteers performed a periodic right-hand pinch grip every second using 5% of their(More)
In view of the potential of global resting blood flow level to confound the interpretation of blood oxygenation level-dependent (BOLD) fMRI studies, we investigated the effect of pronounced elevation in baseline cerebral blood flow (CBF) on BOLD and CBF responses to functional activation. Twelve healthy volunteers performed bilateral finger apposition while(More)
To investigate the coupling between the hemodynamic and metabolic changes following functional brain activation as well as interictal epileptiform discharges (IEDs), blood oxygenation level dependent (BOLD), perfusion and oxygen consumption responses to a unilateral distal motor task and interictal epileptiform discharges (IEDs) were examined via continuous(More)
OBJECTIVE To evaluate the cerebral vasoreactivity using blood oxygenation level dependent functional MRI during carbogen inhalation with 7% CO(2) in Alzheimer's disease and amnestic mild cognitive impairment. PARTICIPANTS AND METHODS Thirty nine subjects were included to be investigated using blood oxygenation level dependent (BOLD) functional MRI at 1.5T(More)
To characterize peritumoral BOLD contrast disorders, 25 patients referred for resection of primary frontal or parietal neoplasms (low-grade glioma (LGG) (n=8); high-grade glioma (HGG) (n=7); meningioma (n=10)) without macroscopic tumoral infiltration of the primary sensorimotor cortex (SM1) were examined preoperatively using BOLD fMRI during simple motor(More)
Although the study of cerebral vasoreactivity using fMRI is mainly conducted through the BOLD fMRI modality, owing to its relatively high signal-to-noise ratio (SNR), ASL fMRI provides a more interpretable measure of cerebral vasoreactivity than BOLD fMRI. Still, ASL suffers from a low SNR and is hampered by a large amount of physiological noise. The(More)
Changes in cerebral perfusion and CO2 cerebrovascular reactivity during and immediately after a sojourn at high altitude remain unclear but may be critical for acclimatization. The aim of the present study was to assess the effects of 6days at 4350m on cerebral perfusion and cerebrovascular reactivity (CVR) to CO2 by arterial spin labeling (ASL) magnetic(More)
In many physiological or pathological situations, the interpretation of BOLD signals remains elusive as the intimate link between neuronal activity and subsequent flow/metabolic changes is not fully understood. During the past decades, a number of biophysical models of the neurovascular coupling have been proposed. It is now well-admitted that these models(More)
The aim of this work was to study cerebral vasoreactivity to hypercapnia in Parkinson's disease (PD) before and after levodopa administration. The prospective study was conducted in 20 patients presenting with PD, using 3T blood oxygenation level-dependent (BOLD) functional MRI (fMRI) covering the whole brain. The hypercapnic stimulus was block-designed(More)
fMRI retinotopic mapping usually relies upon Fourier analysis of functional responses to periodic visual stimuli that encode eccentricity or polar angle in the visual field. Generally, phase estimations are assigned to a surface model of the cerebral cortex and borders between retinotopic areas are eventually determined following ad hoc phase analysis on(More)