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Phase changes in blood oxygenation-level dependent (BOLD) fMRI have been observed in humans; however, their exact origin has not yet been fully elucidated. To investigate this issue, we acquired gradient-echo (GE) BOLD and cerebral blood volume (CBV)-weighted fMRI data in anesthetized cats during visual stimulation at 4.7T and 9.4T, before and after(More)
In functional magnetic resonance imaging (fMRI), the cerebral blood volume (CBV) based approach with exogenous contrast agent has been found to have better spatial specificity than the widely applied blood oxygenation level-dependent (BOLD) method. Recently, an endogenous CBV-based contrast, vascular space occupancy-dependent (VASO) technique, was developed(More)
The cerebral blood volume (CBV) is a crucial physiological indicator of tissue viability and vascular reactivity. Thus, noninvasive CBV mapping has been of great interest. For this, ultrasmall superparamagnetic iron oxide (USPIO) nanoparticles, including monocrystalline iron oxide nanoparticles, can be used as long-half-life, intravascular susceptibility(More)
The amide proton transfer (APT) effect has emerged as a unique endogenous molecular imaging contrast mechanism with great clinical potentials. However, in vivo quantitative mapping of APT using the conventional asymmetry analysis is difficult due to the confounding nuclear Overhauser effect (NOE) and the asymmetry of the magnetization transfer effect. Here,(More)
The mechanism behind previously observed changes in the apparent diffusion coefficient (ADC) during brain activation is not well understood. Therefore, we investigated the signal source and spatial specificity of functional magnetic resonance imaging (fMRI) ADC changes systematically in the visual cortex of cats using diffusion-weighted (DW) spin-echo (SE)(More)
Uptake of administered D-glucose (Glc) or 2-deoxy-D-glucose (2DG) has been indirectly mapped through the chemical exchange (CE) between glucose hydroxyl and water protons using CE-dependent saturation transfer (glucoCEST) magnetic resonance imaging (MRI). We propose an alternative technique-on-resonance CE-sensitive spin-lock (CESL) MRI-to enhance responses(More)
BACKGROUND This study was aimed to examine circadian variations of hepatic antioxidant components, including the Nrf2- pathway, the glutathione (GSH) system, antioxidant enzymes and metallothionein in mouse liver. METHODS AND RESULTS Adult mice were housed in light- and temperature-controlled facilities for 2 weeks, and livers were collected every 4 h(More)
PURPOSE Amide-proton transfer (APT) and amine-water proton exchange (APEX) MRI can be viable to map pH-decreasing ischemic regions. However, their exact contributions are unclear. METHODS We measured APEX- and APT-weighted magnetization transfer ratio asymmetry (denoted as APEXw and APTw), apparent diffusion coefficient, T2 , and T1 images and localized(More)
The protective effects of Rooibos tea (RT), Aspalathus linearis, against damage to the central nervous system (CNS) accompanying aging were examined by both the thiobarbituric acid reaction (TBA) and magnetic resonance imaging (MRI) methods in brains of chronically RT-treated rats. Ad libitum administration of RT was begun with 3-month-old Wistar female(More)