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A technique has been developed for proton magnetic resonance imaging (MRI) of perfusion, using water as a freely diffusable tracer, and its application to the measurement of cerebral blood flow (CBF) in the rat is demonstrated. The method involves labeling the inflowing water proton spins in the arterial blood by inverting them continuously at the neck(More)
Herein, we present a theoretical framework and experimental methods to more accurately account for transit effects in quantitative human perfusion imaging using endogenous magnetic resonance imaging (MRI) contrast. The theoretical transit time sensitivities of both continuous and pulsed inversion spin tagging experiments are demonstrated. We propose(More)
This paper compares the statistical power of BOLD and arterial spin labeling perfusion fMRI for a variety of experimental designs within and across subjects. Based on theory and simulations, we predict that perfusion data are composed of independent observations in time under the null hypothesis, in contrast to BOLD data, which possess marked(More)
Measurement of tissue perfusion is important for the functional assessment of organs in vivo. Here we report the use of 1H NMR imaging to generate perfusion maps in the rat brain at 4.7 T. Blood water flowing to the brain is saturated in the neck region with a slice-selective saturation imaging sequence, creating an endogenous tracer in the form of(More)
The hippocampus has been proposed as the site of neural representation of large-scale environmental space, based upon the identification of place cells (neurons with receptive fields for current position in the environment) within the rat hippocampus and the demonstration that hippocampal lesions impair place learning in the rat. The inability to identify(More)
Written informed consent was obtained prior to all human studies after the institutional review board approved the protocol. A continuous arterial spin-labeling technique with an amplitude-modulated control was implemented by using a single coil at 3.0 T. Adiabatic inversion efficiency at 3.0 T, comparable to that at 1.5 T, was achieved by reducing the(More)
Functional magnetic resonance imaging (fMRI) has become the most widely used modality for visualizing regional brain activation in response to sensorimotor or cognitive tasks. While the majority of fMRI studies have used blood oxygenation level-dependent (BOLD) contrast as a marker for neural activation, baseline drift effects result in poor sensitivity for(More)
Arterial spin labeling (ASL) is capable of noninvasively measuring blood flow by magnetically tagging the protons in arterial blood, which has been conventionally achieved using instantaneous (PASL) or continuous (CASL) RF pulses. As an intermediate method, pseudocontinuous ASL (pCASL) utilizes a train of discrete RF pulses to mimic continuous tagging that(More)
Increasing effort has been devoted to understanding the neural mechanisms underlying decision making during risk, yet little is known about the effect of voluntary choice on risk taking. The Balloon Analog Risk Task (BART), in which subjects inflate a virtual balloon that can either grow larger or explode [Lejuez, C.W., Read, J.P., Kahler, C.W., Richards,(More)
Functional magnetic resonance imaging (fMRI) was used to estimate neural activity while subjects viewed strings of consonants, digits, and shapes. An area on or near the left fusiform gyrus was found that responded significantly more to letters than digits. Similar results were obtained when consonants were used whose visual features were matched with the(More)