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We describe a novel technique for characterizing regional cerebral gray and white matter differences in structural magnetic resonance images by the application of methods derived from functional imaging. The technique involves automatic scalp-editing of images followed by segmentation, smoothing, and spatial normalization to a symmetrical template brain in(More)
Using high-resolution positron emission tomography and the oxygen 15 continuous inhalation method, we examined the changes in cerebral metabolic rate of oxygen, blood flow, blood volume, and oxygen extraction fraction as a function of age in 25 optimally healthy, unmedicated volunteers who ranged in age from 20 to 68 years. Subjects were strictly selected(More)
We characterized, in vivo, using positron emission tomography in baboons, the kinetics and specific binding of i.v. injected [11C]PK 11195 to omega 3 sites in the brain. Following immediate access to brain tissue, the brain kinetics of [11C] K 11195 showed a slow elimination for the 60 min of study. Both coinjection and pulse-chase (at t = 8 min) with(More)
BACKGROUND AND PURPOSE Recent reports have shown an increase in specific binding (in vitro) of [3H]PK 11195 to peripheral-type benzodiazepine receptors in both experimental animals and humans, reflecting a glial/macrophagic reaction within and around focal ischemic insults. We have evaluated by positron emission tomography the time course of changes in(More)
We have determined the rate constants (ki*) of 18F-fluorodeoxyglucose (FDG) in the unlesioned baboon brain, for use in positron emission tomography (PET) measurements of glucose utilization. In contrast to earlier reports, we used a radiosynthesis which guarantees production of FDG essentially uncontaminated by fluorodeoxymannose, and an improved(More)
Studies of central benzodiazepine receptors in the human brain in vivo are now possible using positron emission tomography (PET) and [11C]flumazenil. With the aim of measuring Bmax and Kd in brain regions, we used a two-injection [11C]flumazenil (at high and low specific radioactivity, respectively) pseudo-equilibrium paradigm to evaluate, in seven(More)
This study was conducted to delineate the pattern of the writing impairments in 12 patients with Alzheimer type dementia. The patients performed writing tasks involving regular and irregular words and nonwords given by dictation as well as a decision test composed of printed words and pictures requiring phonologic, lexical, and semantic processing. Writing(More)
We describe a method for identification of brain structures from MRI data sets. The bulk of the paper concerns an automatic system for finding the anterior and posterior commissures [(AC) and (PC)] in the midsagittal plane. These landmarks are key for the definition of the Talairach space, commonly used in stereotactic neurosurgery, in the definition of(More)
In addition to motor impairment, non-demented patients with Parkinson's disease (PD) exhibit a variable degree of cognitive impairment which could indicate dysfunction in the central executive of working memory. In this study, we have employed positron emission tomography measurements of resting brain glucose metabolism (CMRglc) to investigate the neural(More)
The architecture and implementation of VoxeLine, a new interactive environment for display and analysis of 2D and 3D images in real-time, is discussed. This modular software project comprises two main parts: a user part (without programming expertise) and a programming part which permits its adaptation to specific problems. VoxeLine has the ability to deal(More)