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OBJECTIVE The ECAT EXACT HR is a newly designed CTI-Siemens PET scanner with high spatial resolution. Its physical performance with respect to resolution, count rate efficiency, and scatter was investigated and evaluated with phantom studies. MATERIALS AND METHODS The new tomograph consists of three rings of 112 BGO block detectors (50 mm x 23 mm x 30 mm(More)
[11C]Raclopride binding to central D2-dopamine receptors in humans has previously been examined by positron emission tomography (PET). Based on the rapid occurrence of binding equilibrium, a saturation analysis has been developed for the determination of receptor density (Bmax) and affinity (Kd). For analysis of PET measurements obtained with other ligands,(More)
An adjustable computerized atlas of the human brain has been developed, which can be adapted to fit individual anatomy. It is primarily intended for positron emission tomography (PET) but may also be used for single photon emission CT, transmission CT, magnetic resonance imaging, and neuroimaging-based procedures, such as stereotactic surgery and(More)
Previous studies have shown that sensory stimulation and voluntary motor activity increase regional cerebral glucose consumption and regional cerebral blood flow (rCBF). The present study had 3 purposes: (1) to examine whether pure mental activity changed the oxidative metabolism of the brain and, if so, (2) to examine which anatomical structures were(More)
1. We used functional positron emission tomography (PET), measuring regional cerebral blood flow (rCBF) as an index of neuronal activity, to investigate the central processing of itch in 10 healthy volunteers subjected to intracutaneous injections of histamine. 2. The study has unraveled a central representation that depicts a motor intention of the urge to(More)
The computerized brain atlas programme (CBA) provides a powerful tool for the anatomical analysis of functional images obtained with positron emission tomography (PET). With a repertoire of simple transformations, the data base of the CBA is first adapted to the anatomy of the subject's brain represented as a set of magnetic resonance (MR) or computed(More)
The Cologne Special is a prototype of the ECAT EXACT (model 921), a new generation of Siemens-CTI PET scanners. It consists of three rings of 48 BGO block detectors each, covering an axial field of view of 16.2 cm with a patient port of 56.2 cm diameter. This results in a total of 24 rings with 384 crystals each, giving 47 contiguous image planes in(More)
We investigated with PET the cerebral activation pattern elicited by the perceptual maze test (PMT), a neuropsychological test used to evaluate organic brain injury. The PMT examines visuospatial skill, general intelligence, visually guided motor planning, and the ability to obey rules. Eight right-handed volunteers were examined with PET using the tracer(More)
A new dopamine receptor antagonist, Raclopride (S-(-)-3,5-dichloro-N-[(1-ethyl-2-pyrrolidinyl)]methyl-2-hydroxy- 6-methoxybenzamide, FLA 870) (1), has been labelled using [11C]ethyl iodide for alkylation of the nitrogen of the pyrrolidine ring in the corresponding secondary amine (5). The synthesis of 5 and an efficient method for the preparation of(More)
Positron emission tomographic measurements of regional cerebral blood flow (rCBF) were used to investigate central nervous system correlates of fear and anxiety. Volunteers with symptomatic snake phobia were studied while exposed to visual phobogenic, aversive, and neutral stimuli. Anxiety ratings and the number of nonspecific electrodermal fluctuations(More)