Neuroimaging With Calibrated fMRI

Neuroimaging with calibrated FMRI.

The conventional functional MRI (fMRI) map offers information indirectly about localized changes in neuronal activity because it reflects changes in blood oxygenation, not actual neuronal activity. To provide a neurophysiological basis of fMRI, researchers have used electrophysiology to show correlations of fMRI and electric signals. However, quantitative interpretation of the degree to which n...

Application of calibrated fMRI in Alzheimer's disease

Calibrated fMRI based on arterial spin-labeling (ASL) and blood oxygen-dependent contrast (BOLD), combined with periods of hypercapnia and hyperoxia, can provide information on cerebrovascular reactivity (CVR), resting blood flow (CBF), oxygen extraction fraction (OEF), and resting oxidative metabolism (CMRO2). Vascular and metabolic integrity are believed to be affected in Alzheimer's disease ...

Impact of tube hematocrit on calibrated fMRI

where (1 Y) is the blood deoxygenation term, b is the total blood volume fraction, and Hct is the blood hematocrit. While the systemic hematocrit (discharge or macrovessel Hct) does not change during functional activity, studies have not yet assessed the impact of tissue (or microvessel) hematocrit on BOLD signal. Tube hematocrit, defined as the instantaneous volume fraction of red blood cells ...

EEG-fMRI reciprocal functional neuroimaging.

OBJECTIVE Integration of electroencephalography (EEG) and functional magnetic resonance imaging (fMRI) has been pursued in an effort to achieve greater spatio-temporal resolution of imaging dynamic brain activity. We report a data-driven approach to image spatio-temporal features of neural oscillatory activity and event-related activity from continuously recorded EEG and fMRI signals. METHODS...

Perfusion fMRI for functional neuroimaging.