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Measuring the morphology of the cerebral microvasculature by vessel-size imaging (VSI) is a promising approach for clinical applications, such as the characterization of tumor angiogenesis and stroke. Despite the great potential of VSI, this method has not yet found widespread use in practice due to the lack of experience in testing it on healthy humans.(More)
Functional magnetic resonance imaging (fMRI) in auditory experiments is a challenge, because the scanning procedure produces considerable noise that can interfere with the auditory paradigm. The noise might either mask the auditory material presented, or interfere with stimuli designed to evoke emotions because it sounds loud and rather unpleasant.(More)
Several studies have shown that obesity is associated with changes in human brain function and structure. Since women are more susceptible to obesity than men, it seems plausible that neural correlates may also be different. However, this has not been demonstrated so far. To address this issue, we systematically investigated the brain's white matter (WM)(More)
Functional MRI (fMRI) by means of spin-echo (SE) techniques provides an interesting alternative to gradient-echo methods because the contrast is based primarily on dynamic averaging associated with the blood oxygenation level-dependent (BOLD) effect. In this article the contributions from different brain compartments to BOLD signal changes in SE echo planar(More)
Emphysema is a pulmonary disease characterized by alveolar wall destruction, resulting in enlargement of gas exchange spaces without fibrosis. This condition is a part of chronic obstructive pulmonary disease (COPD), which causes 3.5% of deaths worldwide [Anonymous (1990) World Health Stat. Q. Special, 1-51] and contributes greatly to the global burden of(More)
Magnetic resonance imaging studies in patients with phenylketonuria (PKU) revealed white matter alterations that correlated to most recent blood phenylalanine (Phe) concentrations as well as to brain Phe concentrations measured by magnetic resonance spectroscopy. The clinical significance of these changes is unknown. Magnetic resonance imaging data thus(More)
INTRODUCTION Various biomarkers have been reported in recent literature regarding imaging abnormalities in different types of dementia. These biomarkers have helped to significantly improve early detection and also differentiation of various dementia syndromes. In this study, we systematically applied whole-brain and region-of-interest (ROI) based support(More)
In vivo proton magnetic resonance spectroscopy was used to investigate intracerebral phenylalanine (Phe) concentrations in nine patients with classical phenylketonuria (PKU). The study included serial examinations (n = 31; plasma Phe levels: 0.47-2.24 mmol/l) of patients either receiving a Phe-restricted diet (200 mg Phe per day; four patients) or a diet(More)
The transverse relaxation time, T *(2), of hyperpolarized (HP) gas in the lung in vivo is an important parameter for pulse sequence optimization and image contrast. We obtained T *(2) maps of HP (3)He and (129)Xe in guinea pig lungs (n = 17) and in human lungs. Eight different sets of (3)He guinea pig studies were acquired, with variation of slice(More)
In imaging of hyperpolarized noble gases, a knowledge of the diffusion coefficient (D) is important both as a contrast mechanism and in the design of pulse sequences. We have made diffusion coefficient maps of both hyperpolarized (3)He and (129)Xe in guinea pig lungs. Along the length of the trachea, (3)He D values were on average 2.4 cm(2)/sec, closely(More)