A preliminary evaluation of the scanditronix PC2048-15B brain scanner

Holte, S.; Eriksson, Lars; Dahlbom, Magnus

doi:10.1007/bf00631763

Cited by 91 publications

(33 citation statements)

References 4 publications

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“…Patients and healthy volunteers were examined with radiotracers in the order 15 O-H 2 O, DED and FDG on the same day after at least a 4-h fasting period before PET. In severely demented patients, it was found necessary to perform PET during propofol anaesthesia.…”

Section: Methodsmentioning

confidence: 99%

Multitracer study with positron emission tomography in Creutzfeldt-Jakob disease

Engler

Lundberg

Ekbom

et al. 2003

European Journal of Nuclear Medicine and Molecular Imaging

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During the period February 1997 to April 2000, 15 patients with clinical symptoms of Creutzfeldt-Jakob disease (CJD) were referred to Uppsala University PET Centre. Positron emission tomography (PET) was performed to detect characteristic signs of the disease, e.g. neuronal death and/or astrocytosis in the brain. The examinations were performed in one session starting with oxygen-15 labelled water scan to measure regional cerebral blood flow, followed by imaging with the monoamine oxidase B inhibitor N-[(11)C-methyl]- L-deuterodeprenyl (DED) to assess astrocytosis in the brain and finally imaging with fluor-18 2-fluorodeoxyglucose (FDG) to assess regional cerebral glucose metabolism (rCMR(glu)) [corrected]. Nine of the patients fulfilled the clinical criteria of probable CJD. In eight of them, FDG and DED imaging revealed, in comparison with normal controls, a typical pattern characterized by a pronounced regional decrease (<2SD) in glucose brain metabolism, indicative of neuronal dysfunction; this was accompanied by a similar increase (>2SD) in DED binding, indicating astrocytosis. These changes were most pronounced in the cerebellum and the frontal, occipital and parietal cortices, whereas the pons, the thalamus and the putamen were less affected and the temporal cortex appeared unaffected. The cerebral blood flow showed a pattern similar to that observed with FDG. In the ninth patient, analysis with DED was not possible. The diagnosis of definite CJD according to international consensus criteria was confirmed in six of these patients. In one patient with probable CJD, protease-resistant prion protein (PrPres) could not be demonstrated. In two patients with probable CJD, autopsy was not allowed. Computed tomography and magnetic resonance imaging, performed in four and seven of these nine patients respectively, showed unspecific, mainly atrophic changes. In six other patients, the PET examinations gave a different pattern. In three of them, high rCMR(glu) was noticed in parts of the brain, particularly in the temporal lobes and basal ganglia, which could suggest encephalitis. One of the patients had Sjögren's syndrome, one had paraneoplastic limbic encephalitis and the third recovered spontaneously. In the other three patients, the DED binding was normal despite a hypometabolic glucose pattern. In conclusion, the PET findings obtained using DED and FDG paralleled neuropathological findings indicating neuronal dysfunction and astrocytosis, changes that are found in CJD.

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Section: Methodsmentioning

confidence: 99%

Multitracer study with positron emission tomography in Creutzfeldt-Jakob disease

Engler

Lundberg

Ekbom

et al. 2003

European Journal of Nuclear Medicine and Molecular Imaging

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“…The scanners enable simultaneous measurement of the radioactivity from 15 transaxial slices 6.8 mm apart with an in-plane resolution of 5 mm (Holte et al, 1989) and 6 mm (GE4096-15WB) (Kops et al, 1990) full-width half-maximum, respectively. Correction for tissue attenuation of 511 keV gamma radiation was measured with an external 68 Ge ring.…”

Section: Radiochemistry and Petmentioning

confidence: 99%

L-DOPA modulates striatal dopaminergic function in vivo: Evidence from PET investigations in nonhuman primates

Tedroff

Torstenson

Hartvig

et al. 1997

Synapse

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Significant increases in striatal L-[11C]DOPA retention were observed in adult female rhesus monkeys with positron emission tomography (PET) following administration of drugs that increase cerebral L-DOPA concentrations. The monkeys were scanned twice: at baseline (using 10-50 micrograms of tracer substance) and during continuous administration of L-DOPA (3 or 15 mg/kg/h) and 6-R-Erythro-4,5,6,7-tetrahydrobiopterin (6R-BH4) (5 mg/kg/h) and during combined administration of both drugs. PET scans of L-[11C]DOPA distribution were obtained in GE2048-15B or GE4096-15WB Plus positron tomographs. In all studies the specific striatal L-[11C]DOPA influx rate increased by an average of 17-20%. These increases were significantly higher than the retest variability obtained with saline infusions under identical experimental conditions. In individual monkeys the magnitude of increase in the striatal L-[11C]DOPA influx rate varied from no effect of the drug infusion to a 45% increase. Taken together, the results of this study demonstrate that L-DOPA in itself can affect dopaminergic neurotransmission in vivo and also adds further evidence that the neuromodulatory effects of the amino acid are predominantly autoreceptor antagonist-like. The findings most likely have importance for the further understanding of the dopaminergic system in neurodegenerative and psychiatric disorders.

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“…The PET investigations were performed on a GEMS 2048-15B scanner (General Electric Medical Systems) 20 as described in detail earlier. 9 A computerized reorientation procedure was used to accurately align the consecutive PET studies to enable exact intraindividual comparisons.…”

Section: Positron Emission Tomographymentioning

confidence: 99%

Middle Cerebral Artery Occlusion and Reperfusion in Primates Monitored by Microdialysis and Sequential Positron Emission Tomography

Enblad

Frykholm²,

Valtysson³

et al. 2001

Stroke

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Background and Purpose-In a previous investigation concerning the hemodynamic and metabolic changes over time displayed by sequential positron emission tomography (PET) in a middle cerebral artery (MCA) occlusion/reperfusion primate model, a metabolic threshold for irreversible ischemia could be identified (reduction of metabolic rate of oxygen [CMRO 2 ] to Ϸ60% of the contralateral hemisphere). To evaluate the potential of microdialysis (MD) as an instrument for chemical brain monitoring, the aim of this subsequent study was to relate the chemical changes in MD levels directly to the regional metabolic status (CMRO 2 above or below the metabolic threshold) and the occurrence of reperfusion, as assessed by PET. Methods-Continuous MD (2 probes in each brain) and sequential PET measurements were performed during MCA occlusion (2 hours) and 18 hours (mean) of reperfusion in 8 monkeys (Macaca mulatta). Energy-related metabolites (lactate, pyruvate, and hypoxanthine) and glutamate were analyzed. The MD probe regions were divided into 3 categories on the basis of whether CMRO 2 was below or above 60% of the contralateral region (metabolic threshold level) during MCA occlusion and whether reperfusion was obtained: severe ischemia with reperfusion (nϭ4), severe ischemia without reperfusion (nϭ4), and penumbra with reperfusion (nϭ5). Results-The lactate/pyruvate ratio, hypoxanthine, and glutamate showed similar patterns. MD probe regions with severe ischemia and reperfusion and probe regions with severe ischemia and no reperfusion displayed high and broad peaks, respectively, during MCA occlusion, and the levels almost never decreased to baseline. Penumbra MD probe regions displayed only slight transient increases during MCA occlusion and returned to baseline. Conclusions-This experimental study of focal ischemia showed that the extracellular changes of energy-related metabolites and glutamate differed depending on the ischemic state of the brain during MCA occlusion and depending on whether reperfusion occurred. If MD proves to be beneficial in clinical practice, it appears important to observe relative changes over time.

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A preliminary evaluation of the scanditronix PC2048-15B brain scanner

Cited by 91 publications

References 4 publications

Multitracer study with positron emission tomography in Creutzfeldt-Jakob disease

Multitracer study with positron emission tomography in Creutzfeldt-Jakob disease

L-DOPA modulates striatal dopaminergic function in vivo: Evidence from PET investigations in nonhuman primates

Middle Cerebral Artery Occlusion and Reperfusion in Primates Monitored by Microdialysis and Sequential Positron Emission Tomography

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