[en] This volume presents coverage of the use of positron emission tomography (PET) to study the human brain. The contributors assess new developments in high-resolution positron emission tomography, cyclotrons, radiochemistry, and tracer kinetic models, and explore the use of PET in brain energy metabolism, blood flow, and protein synthesis measurements, receptor analysis, and pH determinations, In addition, they discuss the relevance and applications of positron emission tomography from the perspectives of physiology, neurology, and psychiatry

No abstract available

No abstract available

No abstract available

[en] The average number of prompt neutrons per ²³⁵U and ²³⁹Pu fission are being measured at the fast zero-power reactor (FRO) at Studsvik, Sweden. Special attention is paid to the fission resonance region where earlier measurements with good energy resolution have given different ν-bar-values for different groups of resonances. As fission neutron detector a large liquid scintillator is used. The reactor neutron energy spectrum is measured in separate time-of-flight and proton-recoil detector experiments. The experimental technique is described, and preliminary ν-bar-values averaged over the fast reactor spectrum from 0-70 keV are given. (author)

[en] Five patients with cerebrospinal fluid (CSF) rhinorrhea were investigated with computed tomography (CT) and positron emission tomography (PET) to localize the site of a CSF fistula. After intrathecal injection of 10 MBq of ⁶⁸Ga-EDTA, radioactivity was demonstrated in the basal cisterns. In three cases, the site of the fistula was visualized with PET. It is not always possible to demonstrate a CSF leakage with CT cisternography (CTC) using metrizamide, particularly in cases with minute fistulas or intermittent CSF rhinorrhea. With further experience and improved PET techniques, it may be possible to detect even very small fistulas

[en] Our group is at the time trying to acquire the necessary resources for physiological investigations. A 4-dimensional instrument is being constructed and efficient methods of labeling carbon hydrates and polypeptides have been devised. (orig./VJ)

[en] Brief item

[en] The diagnostic value of positron emission tomography (PET) was evaluated in 41 examinations of 40 patients. ⁶⁸Ga-EDTA was used as a positron source. The findings were correlated with those of conventional CT scanning. A clearly pathologic accumulation of ⁶⁸Ga-EDTA was detected in 29 of 41 PET scans. The precontrast CT scans were negative in 11 and non-conclusive in one patient. CT after administration of contrast medium was performed in 29 patients. Of these 21 had a clearly pathologic PET scan and 14 had visible contrast enhancement on CT examination. The injury of the blood-brain barrier thus was better demonstrated with PET than with CT. The topologic diagnosis was, however, better demonstrated at CT. It seems that CT and PET are supplementary examinations and that PET is superior to CT in the detection of injury of or absence of the blood-brain barrier. (Auth.)

[en] We used D-[U-11C]glucose to evaluate transport and metabolism of glucose in the brain in eight nondiabetic and six insulin-dependent diabetes mellitus (IDDM) subjects. IDDM subjects were treated by continuous subcutaneous insulin infusion. Blood glucose was regulated by a Biostator-controlled glucose infusion during a constant insulin infusion. D-[U-11C]-glucose was injected for positron emission tomography studies during normoglycemia as well as during moderate hypoglycemia [arterial plasma glucose 2.74 +/- 0.14 in nondiabetic and 2.80 +/- 0.26 mmol/l (means +/- SE) in IDDM subjects]. Levels of free insulin were constant and similar in both groups. The tracer data were analyzed using a three-compartment model with a fixed correction for 11CO2 egression. During normoglycemia the influx rate constant (k1) and blood-brain glucose flux did not differ between the two groups. During hypoglycemia k1 increased significantly and similarly in both groups (from 0.061 +/- 0.007 to 0.090 +/- 0.006 in nondiabetic and from 0.061 +/- 0.006 to 0.093 +/- 0.013 ml.g-1.min-1 in IDDM subjects). During normoglycemia the tracer-calculated metabolism of glucose was higher in the whole brain in the nondiabetic than in the diabetic subjects (22.0 +/- 1.9 vs. 15.6 +/- 1.1 mumol.100 g-1.min-1, P less than 0.01). During hypoglycemia tracer-calculated metabolism was decreased by 40% in nondiabetic subjects and by 28% in diabetic subjects. The results indicate that uptake of glucose is normal, but some aspect of glucose metabolism is abnormal in a group of well-controlled IDDM subjects