Functional magnetic resonance imaging (fMRI) provides an indirect reflection of neural activity change in the working brain through detection of blood oxygenation level dependent (BOLD) signal changes. Although widely used to map patterns of brain activation, fMRI has not yet met its potential for clinical and pharmacological studies due to difficulties in quantitatively interpreting the BOLD s...

Estimating placental oxygen transport capacity is highly desirable, as impaired placental function is associated with fetal growth restriction (FGR) and poor neonatal outcome. In clinical obstetrics, a noninvasive method to estimate the placental oxygen transport is not available, and the current methods focus on fetal well-being rather than on direct assessment of placental function. In this a...

fMRI does not measure neural activity directly. Instead, it measures small and variable changes in the ratio of oxygenated to deoxygenated blood in the brain when a particular task is performed or stimulus presented—the so-called BOLD, or blood oxygen level-dependent, response. Firing neurons, like working muscles, require oxygen; follow the trail of oxygenated hemoglobin, and you find neural a...

Background Blood Oxygen Level Dependent (BOLD) magnetic resonance (MR) is a novel imaging tool that is able to detect tissue oxygenation and has recently been utilized to evaluate renal function in patients with renal artery stenosis (RAS). Renal BOLD imaging is typically performed before and after a furosemide stimulus to assess kidney viability. Furosemide blocks the sodium-potassium2chloride...

Blood oxygen level-dependent (BOLD) MRI data of kidney, while indicative of tissue oxygenation level (Po2), is in fact influenced by multiple confounding factors, such as R2, perfusion, oxygen permeability, and hematocrit. We aim to explore the feasibility of extracting tissue Po2 from renal BOLD data. A method of two steps was proposed: first, a Monte Carlo simulation to estimate blood oxygen ...

Background BOLD CMR has been shown to be able to detect myocardial perfusion differences. However, validation of BOLD CMR against FFR is lacking. Aim of our study was to analyze the potential diagnostic accuracy of blood oxygen level-dependent (BOLD) cardiac magnetic resonance imaging (CMR) in comparison to invasively measured fractional flow reserve (FFR) which served as gold standard for a he...

Functional magnetic resonance imaging (fMRI) has become a leading tool in the evaluation of the human brain function. In fMRI the activation induced blood oxygenation changes in the brain can be detected with an inherent blood oxygen level dependent (BOLD) contrast. Even small blood oxygen fluctuations in a resting brain can be depicted with the BOLD contrast. This thesis focuses on characteriz...

Imaging of cerebral oxygen metabolism is useful for selecting and monitoring therapy, matching patients with interventions, and optimizing outcomes while reducing the incidence of hemorrhagic changes. We aimed to measure oxygen metabolism using magnetic resonance (MR) imaging. Because the magnetic susceptibility of hemoglobin varies with its redox status, the regional oxygen saturation should b...

We report Blood Oxygen Level Dependent (BOLD) signal changes recorded in the brain of an elite breath-hold diver during voluntary dry long by means fMRI. An independent component analysis (ICA) method was applied to extract areas that are putatively involved apnea process network. discuss hypothesis these BOLD variations express functional adaptive diving response under at rest. This is a preli...