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EN
The complexity of the hardware and the amount of data collected during the PET imaging process require application of modern methods of efficient data organization and processing. In this article, we will discuss the data structures and the flow of collected data from the novel TOF-PET medical scanner that is being developed at the Jagiellonian University. The developed data format reflects the registration process of the γ quanta emitted from positron electron annihilation, front-end electronic structure, and required input information for the image reconstruction. In addition, the system database fulfills possible demands of the evolving J-PET project.
EN
Preliminary design of a spherical brain PET (SBPET) using liquid xenon (LXe) as detector is considered in this research work. The major advantage of a spherical design is the large solid angle of acceptance which improves the sensitivity and increases signal-to-noise ratio (SNR) of the image. The use of a liquid active medium enabled us to design a spherical detector. LXe, due to the intrinsic physical properties, is an excellent liquid medium for accurate tracking of gamma rays in the relevant energy range. The performance of SBPET was evaluated by Monte Carlo simulation tools (GATE) and compared to ECAT HRRT. The numerical results showed the SBPET has a sensitivity of 1.14% and spatial resolution of ~2.7 mm FWHM which is superior to ECAT HRRT especially at high-count rates.
EN
A review of results on the design and operation of the new efficient Dense Plasma Focus device PF-6 of medium size (transportable) having bank energy of ca. 7 kJ and possessing a long lifetime is presented. New data on the interaction of the pulsed fast ion beams and dense plasma streams generated at this apparatus with various materials are given. These results are compared with the analogous information received at the biggest facility PF-1000. It is shown that it is possible to have about the same power flux density (in the range of 105 109 W/cm2) in both devices however in different areas. Doses of soft X-rays produced by the device within the resists for the goals of microlithography and micromachining appear to be several times less that it is with the conventional X-ray tube. In biological application of this device, medium- and hard-energy X-rays are exploited in the field of radioenzymology. It was found that the necessary dose producing activation/inactivation of enzymes can be by several orders of magnitude lower if used at a high-power flux density in comparison with those received with isotope sources. In medicine, short-life isotope production for the goals of the positron emission tomography (medicine diagnostics) is possible by means of the fast ions generated within DPF. All these experiments are discussed in the framework of pulsed radiation physics and chemistry in its perfect sense thereto the criteria are formulated.
EN
Positron Emission Tomography (PET) is a method for determining biochemical and physiological processes in vivo in a quantitative manner. The most commonly used radionuclides are 11C, 13N, 15O and 18F, with respective half-lives of approximately 20 min, 10 min, 2 min, and 110 min. 18F labeled FDG (fluoro-2-deoxy-D-glucose) is now the most frequently used radiopharmaceutical and finds its application prominently in the field of oncology. Originally, the production of these radionuclides was performed with the existing accelerators, designed for nuclear physics, but with increasing interest in the PET methodology specially designed PET-production cyclotrons became available. The nuclear reactions involved are (p,n), (d,n), (p,a) and (d,a) and the thresholds for the nuclear reactions involved are 5 to 6 MeV. Based on these values and on other parameters, a proton 15 to 20 MeV cyclotron is often chosen. Since the half-life of a radionuclide limits the production time, the maximum beam current is an important parameter, together with the target construction, for the ultimate yield obtainable. In the development of special PET production cyclotrons, attention has also been paid to improve the extraction efficiency and the possibility of multiple extractions by designing negative ion cyclotrons. Commercial cyclotrons can often be acquired as an easy to operate integrated radionuclide production unit including targetry and some units. Regional FDG factories are nowadays being created to fulfil the demand for PET radiopharmaceutics. The possible choices in commercially available cyclotrons for the production of PET radionuclides will be discussed.
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