With the idea of finding a more selective radiotracer for imaging herpes simplex virus type 1 thymidine kinase (HSV1-tk) gene expression by means of positron emission tomography (PET), a novel [¹⁸F]fluorine radiolabeled pyrimidine with 4-hydroxy-3-(hydroxymethyl)butyl side chain at N-1 (HHB-5-[¹⁸F]FEP) was prepared and evaluated as a potential PET probe. Unlabeled reference compound, HHB-5-FEP,...

The 5-hydroxytryptamine type 2a (5-HT(2A)) selective radiotracer [(18)F]altanserin has been subjected to a quantitative micro-positron emission tomography study in Lister Hooded rats. Metabolite-corrected plasma input modeling was compared with reference tissue modeling using the cerebellum as reference tissue. [(18)F]altanserin showed sufficient brain uptake in a distribution pattern consisten...

The in vivo regional distribution of [18F]GBR 13119 (1-[(4-[18F]fluorophenyl(phenyl)methoxy)ethyl]-4-(3-phenylpropyl) piperazine), a specific dopamine reuptake inhibitor, was examined in brains of C57BL/6 mice after MPTP treatment. At 2 weeks post MPTP the in vivo specific binding of [18F]GBR 13119 in striatum was decreased 63% relative to age and sex-matched controls. Animals studied at 6 and ...

Reactive oxygen species (ROS) are believed to play a major role in the proinflammatory, M1-polarized form of neuroinflammation. However, it has been difficult to assess the role of ROS and their role in neuroinflammation in animal models of disease because of the absence of probes capable of measuring their presence with the functional imaging technique positron emission tomography (PET). This ...

Radiotracer experiments are carried out in order to determine the mean residence time (MRT) as well as percentage of dead zone, V dead (%), in an integrated mixer consisting of Rushton and pitched blade turbine (PBT). Conventionally, optimization was performed by varying one parameter and others were held constant (OFAT) which lead to enormous number of experiments. Thus, in this study, a 4-fac...

Twelve patients with solitary autonomous thyroid nodules were scanned with [99mTc] pertechnetate and by fluorescent imaging. Nodular dimensions were essentially identical on the two types of scans, but the relative scan densities in the nodular versus extranodular areas demonstrated striking differences. In 11 of the 12 patients, the ratio of nodular-to-extranodular radiotracer accumulation was...

Dynamic positron emission tomography (PET) can monitor spatiotemporal distribution of radiotracer in vivo. The spatiotemporal information can be used to estimate parametric images of radiotracer kinetics that are of physiological and biochemical interests. Direct estimation of parametric images from raw projection data allows accurate noise modeling and has been shown to offer better image qual...

At the "Radiochemistry Laboratory" of Accelerators and Applied Superconductivity Laboratory, LASA, several production and quality assurance methods for short-lived and high specific activity radionuclides, have been developed. Presently, the irradiations are carried out at the Scanditronix MC40 cyclotron (K=38; p, d, He-4 and He3) of JRC-Ispra, Italy, of the European Community, while both chemi...