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Wyświetlanie 1-14 z 14
Tytuł:
Compact cyclotrons for the production of tracers and radiopharmaceuticals
Autorzy:
Paans, A.
Powiązania:
https://bibliotekanauki.pl/articles/146155.pdf
Data publikacji:
2003
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
positron emission tomography (PET)
cyclotron
radionuclide production
Opis:
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.
Źródło:
Nukleonika; 2003, 48,suppl.2; 169-172
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization of soft X-ray tomography on the COMPASS tokamak
Autorzy:
Imríšek, M.
Mlynář, J.
Löffelmann, V.
Weinzettl, V.
Odstrčil, T.
Odstrčil, M.
Tomeš, M.
Powiązania:
https://bibliotekanauki.pl/articles/146251.pdf
Data publikacji:
2016
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
soft X-ray
tomography
Tikhonov regularization
tokamak
Opis:
The COMPASS tokamak is equipped with the soft X-ray (SXR) diagnostic system based on silicon photodiode arrays shielded by a thin beryllium foil. The diagnostic is composed of two pinhole cameras having 35 channels each and one vertical pinhole camera with 20 channels, which was installed recently to improve tomographic inversions. Lines of sight of the SXR detectors cover almost complete poloidal cross section of the COMPASS vessel with a spatial resolution of 1–2 cm and temporal resolution of about 3 s. Local emissivity is reconstructed via Tikhonov regularization constrained by minimum Fisher information that provides reliable and robust solution despite limited number of projections and ill-conditionality of this task. Improved border conditions and numerical differentiation matrices suppressing artifacts in reconstructed radiation were implemented in the code. Furthermore, a fast algorithm eliminating iterative processes was developed, and it is foreseen to be tested in real-time plasma control.
Źródło:
Nukleonika; 2016, 61, 4; 403-408
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation, quality control and biodistribution studies of [61Cu]-oxinate for PET tumor imaging
Autorzy:
Jalilian, A. R.
Zolghadri, S.
Faghihi, R.
Yousefnia, H.
Garousi, J.
Shafaii, K.
Bolourinovin, F.
Powiązania:
https://bibliotekanauki.pl/articles/148094.pdf
Data publikacji:
2009
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
copper-61
8-hydroxyquinoline
positron emission tomography
fibrosarcoma
Opis:
Targeting apoptosis is an interesting issue in molecular imaging and various modalities have been presented. However, recent experiences in nuclear pharmacy demonstrated the application of small tracer molecules is more desired. This work was conducted for production of a radiolabeled copper complex, i.e. 61Cu-oxinate as a potential PET tracer for apoptosis imaging in oncology. Cu-61 was prepared by natural zinc target irradiation with 22 MeV protons (150 miA) via the natZn(p, xn)61Cu nuclear reaction with a yield of 3.33 mCi/miAh. In order to obtain the best labeling method, optimization reactions were performed for pH, temperature and concentration followed by solid phase extraction. Biodistribution of the tracer was studied in wild-type and fibrosarcoma bearing mice. Under the optimized conditions, radio-thin-layer chromatography (RTLC) and HPLC showed radiochemical purities of 99.99% and 97% respectively (with a minimum specific activity of 16 Ci/mM). Biodistribution of the tracer in fibrosarcoma bearing mice demonstrated a significant tumor uptake after 3 h. Tumor:blood and tumor:muscle ratios were 2.0 and 6.0 after 3 h, respectively.
Źródło:
Nukleonika; 2009, 54, 3; 175-179
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of the compress sensing theory for improvement of the TOF resolution in a novel J-PET instrument
Autorzy:
Raczyński, L.
Moskal, P.
Kowalski, P.
Wiślicki, W.
Bednarski, T.
Białas, P.
Czerwiński, E.
Gajos, A.
Kapłon, Ł.
Kochanowski, A.
Korcyl, G.
Kowal, J.
Kozik, T.
Krzemień, W.
Kubicz, E.
Niedźwiecki, S.
Pałka, M.
Rudy, Z.
Salabura, P.
Gupta-Sharma, N.
Silarski, M.
Słomski, A.
Smyrski, J.
Strzelecki, A.
Wieczorek, A.
Zieliński, M.
Zoń, N.
Powiązania:
https://bibliotekanauki.pl/articles/146280.pdf
Data publikacji:
2016
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
compressed sensing
positron emission tomography
time-of-flight
Opis:
Nowadays, in positron emission tomography (PET) systems, a time of fl ight (TOF) information is used to improve the image reconstruction process. In TOF-PET, fast detectors are able to measure the difference in the arrival time of the two gamma rays, with the precision enabling to shorten signifi cantly a range along the line-of-response (LOR) where the annihilation occurred. In the new concept, called J-PET scanner, gamma rays are detected in plastic scintillators. In a single strip of J-PET system, time values are obtained by probing signals in the amplitude domain. Owing to compressive sensing (CS) theory, information about the shape and amplitude of the signals is recovered. In this paper, we demonstrate that based on the acquired signals parameters, a better signal normalization may be provided in order to improve the TOF resolution. The procedure was tested using large sample of data registered by a dedicated detection setup enabling sampling of signals with 50-ps intervals. Experimental setup provided irradiation of a chosen position in the plastic scintillator strip with annihilation gamma quanta.
Źródło:
Nukleonika; 2016, 61, 1; 35-39
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and biological evaluation of [61Cu]bleomycin complex as a possible PET radiopharmaceutical in normal and fibrosarcoma-bearing animals
Autorzy:
Jalilian, A. R.
Zandi, H.
Sardari, D.
Akhlaghi, M.
Kamali-Dehghan, M.
Shafaei, K.
Majdabadi, A.
Powiązania:
https://bibliotekanauki.pl/articles/148090.pdf
Data publikacji:
2009
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
radiopharmaceutical
copper-61
bleomycin
positron emission tomography
fibrosarcoma
Opis:
[61Cu]bleomycin ([61Cu]BLM) was prepared using [61Cu]CuCl2 produced via natZn(p,x)61Cu. [61Cu]BLM was prepared under optimized conditions (room temperature, 45 min, 0.1 mg bleomycin for 92.5–370 MBq 61CuCl2) with radiochemical purity over 98% shown by HPLC and RTLC. [61Cu]BLM was administered into normal and tumor bearing rodents up to 210 min followed by biodistribution and co-incidence imaging studies. A significant tumor/non tumor accumulation was observed either by animal sacrification or an imaging method. [61Cu]BLM can be a potential PET radiotracer for tumor imaging.
Źródło:
Nukleonika; 2009, 54, 2; 135-141
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A virtual laboratory for radiotracer and sealed-source applications in industry
Autorzy:
Mohammed, Mohammed Siddig H.
Banoqitah, Essam M.
Elmoujarkach, Ezzat
Alhawsawi, Abdulsalam M.
Djouider, Fathi
Powiązania:
https://bibliotekanauki.pl/articles/1841639.pdf
Data publikacji:
2021
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
sealed sources
radiotracers
industrial gamma tomography
simulation
GATE
Opis:
Radioactive sealed sources and radiotracer techniques are used to diagnose industrial process units. This work introduces a workspace to simulate four sealed sources and radiotracer applications, namely, gamma scanning of distillation columns, gamma scanning of pipes, gamma transmission tomography, and radiotracer fl ow rate measurements. The workspace was created in Geant4 Application for Tomographic Emission (GATE) simulation toolkit and was called Industrial Radioisotope Applications Virtual Laboratory. The fl exibility of GATE and the fact that it is an open-source software render it advantageous to radioisotope technology practitioners, educators, and students. The comparison of the simulation results with experimental results that are available in the literature showed the effectiveness of the virtual laboratory.
Źródło:
Nukleonika; 2021, 66, 1; 21-27
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of [66Ga]oxine complex; a possible PET tracer
Autorzy:
Jalilian, A.
Rowshanfarzad, P.
Sabet, M.
Rahiminejad-Kisomi, A.
Rajamand, A.
Powiązania:
https://bibliotekanauki.pl/articles/146276.pdf
Data publikacji:
2006
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
gallium-66
oxine
positron emission tomography
blood cell labeling
stability
Opis:
The aim of this work is development of a possible blood cell labeling agent for ultimate use in PET. Gallium-66 (T1/2 = 9.49 h) is an interesting radionuclide that has a potential for positron emission tomography (PET) imaging of biological processes with intermediate to slow target tissue uptake. Oxine has been labeled with this radionuclide in the form of [66Ga]gallium chloride for its possible diagnostic properties. In this study, 66Ga was produced at a 30 MeV cyclotron (IBA-Cyclone 30) via the 66Zn(p,n)66Ga reaction. The production yield was 445.5 MBq/mAh. The [66Ga]oxine complex was obtained at pH = 5 in phosphate buffer medium at 37°C in 10 min. Radio-TLC showed a radiochemical purity of more than 98 š 2%. The chemical stability of the complex was checked in vitro with a specific activity of 1113 GBq/mmol. The serum stability and log P of the complex were calculated. The produced [66Ga]oxine can be used for diagnostic studies, due to its desirable physico-chemical properties both in vitro and in vivo according to internationally accepted limits.
Źródło:
Nukleonika; 2006, 51, 3; 155-159
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation of computed tomography (CT) images using a Monte Carlo approach
Autorzy:
Wysocka-Rabin, A. M.
Qamhiyeh, S.
Jäkel, O.
Powiązania:
https://bibliotekanauki.pl/articles/147601.pdf
Data publikacji:
2011
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
X-ray tomography
Monte Carlo (MC) method
treatment planning
hadrontherapy
Opis:
Heavy ion treatment planning uses an empirical scanner-dependent calibration relation between computed tomography (CT) numbers and ion range. Any deviation in the values of CT numbers will cause a drift in the calibration curve of the CT scanner, which can reduce the accuracy of treatment beam delivery. To reduce uncertainty in the empirical estimation of CT numbers, we developed a simulation that takes into consideration the geometry, composition, and physical process that underlie their measurement. This approach uses Monte Carlo (MC) simulations, followed by a simple filtered back-projection reconstruction. The MC code used is BEAMnrc/EGSnrc. With the manufacturer’s permission, we simulated the components (X-ray tube, associated filters and beam shapers) of a Siemens Emotion CT. We then generated an initial beam shape and spectra, and performed further simulations using the phantom with substitutes. We analyzed the resulting phase space file to calculate projections, taking into account the energy response of the CT detectors. Then, we applied a simple reconstruction algorithm to the calculated projections in order to receive the CT image.
Źródło:
Nukleonika; 2011, 56, 4; 299-304
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Monte Carlo calculated CT numbers for improved heavy ion treatment planning
Autorzy:
Qamhiyeh, S.
Wysocka-Rabin, A.
Jäkel, O.
Powiązania:
https://bibliotekanauki.pl/articles/148658.pdf
Data publikacji:
2014
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
X-ray tomography
Monte Carlo (MC) method
treatment planning
hadrontherapy
Opis:
Better knowledge of CT number values and their uncertainties can be applied to improve heavy ion treatment planning. We developed a novel method to calculate CT numbers for a computed tomography (CT) scanner using the Monte Carlo (MC) code, BEAMnrc/EGSnrc. To generate the initial beam shape and spectra we conducted full simulations of an X-ray tube, filters and beam shapers for a Siemens Emotion CT. The simulation output files were analyzed to calculate projections of a phantom with inserts. A simple reconstruction algorithm (FBP using a Ram-Lak filter) was applied to calculate the pixel values, which represent an attenuation coefficient, normalized in such a way to give zero for water (Hounsfield unit (HU)). Measured and Monte Carlo calculated CT numbers were compared. The average deviation between measured and simulated CT numbers was 4 ± 4 HU and the standard deviation σ was 49 ± 4 HU. The simulation also correctly predicted the behaviour of H-materials compared to a Gammex tissue substitutes. We believe the developed approach represents a useful new tool for evaluating the effect of CT scanner and phantom parameters on CT number values.
Źródło:
Nukleonika; 2014, 59, 1; 15-23
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preliminary design and simulation of a spherical brain PET system (SBPET) with liquid xenon as scintillator
Autorzy:
Moghaddam, N. M.
Karimian, A.
Mostajaboddavati, S. M.
Vondervoort, E.
Sossi, V.
Powiązania:
https://bibliotekanauki.pl/articles/146444.pdf
Data publikacji:
2009
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
positron emission tomography (PET)
Monte Carlo simulation
GATE
liquid xenon
brain imaging
Opis:
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.
Źródło:
Nukleonika; 2009, 54, 1; 33-38
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gamma-ray computed tomography as a tool to evaluate porosity changes along depth for surface crusted soils
Autorzy:
Pires, L. F.
Bacchi, O. O. S.
Reichardt, K.
Dias, N. M. P.
Powiązania:
https://bibliotekanauki.pl/articles/146838.pdf
Data publikacji:
2007
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
gamma-ray attenuation
soil density
soil structure
soil surface sealing
241 Am
applied nuclear physics
gamma tomography
Opis:
Assessment of changes in porosity (ö) along depth for soils with surface crusting is difficult because conventional soil physical investigation tools are destructive and usually require a long period of time for preparation and analysis of the samples. Computed tomography (CT) has frequently been used as a method to evaluate soil structure in a nondestructive, sensitive, and rapid manner. CT data can be used for measuring at a millimetric scale changes in ö along depth for soils with surface crusting. The main objective of this work was to investigate the sensibility of the gamma-ray CT to assess soil structural changes along depth in samples presenting structural crust. CT images were taken with a first generation scanner of 1.14 mm resolution along eight different soil layers within the 0 28 mm depth. Porosity increased along depth up to the 14 17.5 mm layer. Through the analysis of the ö distribution of each layer it was possible to show that the sealed surface layer presented ö values of approximately 30%, while the other layers were greater than 30% up to 60% (macropore regions). The sealing crust thickness was estimated to be in the range of 2.3 3.5 mm.
Źródło:
Nukleonika; 2007, 52, 3; 125-131
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
PF-6 an effective plasma focus as a source of ionizing radiation and plasma streams for application in material technology, biology and medicine
Autorzy:
Gribkov, V.
Dubrovsky, A.
Scholz, M.
Jednorog, S.
Karpiński, L.
Tomaszewski, K.
Paduch, M.
Miklaszewski, R.
Pimenov, V.
Ivanov, L. I.
Dyomina, E. V.
Maslyaev, S. A.
Orlova, M. A.
Powiązania:
https://bibliotekanauki.pl/articles/147424.pdf
Data publikacji:
2006
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
dense plasma focus (DPF)
ion beam
plasma beam
X-ray beams
surface damage
microlithography
radioenzymology
positron emission tomography (PET)
Opis:
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.
Źródło:
Nukleonika; 2006, 51, 1; 55-62
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gamma-ray computed tomography SCANNERS for applications in multiphase system COLUMNs
Autorzy:
Calvo, W. A. P.
Hamada, M. M.
Sprenger, F. E.
Vasquez, P. A. S.
Rela, P. R.
Martins, J. F. T.
de Matos Pereira, J. C. S.
Omi, N.
de Mesquita, C. H.
Powiązania:
https://bibliotekanauki.pl/articles/148082.pdf
Data publikacji:
2009
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
industrial computed tomography
multiphase flow systems
non-destructive testing
gas absorption column
industrial process optimization
packed distillation columns
scanning systems
Opis:
Gamma-ray tomography experiments have been carried out to detect spatial patterns in the porosity, in a 0.27 m diameter packed steel column using a first generation computed tomography (CT) system. The CT scanner consists of a NaI(Tl) detector 5.08 cm in diameter, and an encapsulated 137Cs (3.7 GBq) radioactive source, located opposite to the center of the detector. The detector and the source, mounted on a fixed support and the column, can rotated and dislocate by two stepping motors controlled through a microprocessor. Different sizes of stainless steel Raschig rings (12.6, 37.9 and 76 mm) have been examined. The primary objective of this work is to detect spatial patterns and statistical information on porosity variation in packed distillation columns. Horizontal scans, at different vertical positions of the packed bed were made for each size of Raschig rings. Radial porosity variation within the packed bed has been determined. This study has demonstrated that the porosity and its spatial distribution in a metallic packed column can be measured with adequate spatial resolution using the gamma-ray tomography technique. After validation of this first generation CT, the turntable design to rotate and dislocate the 60Co or 137Cs sealed gamma-ray sources and multidetector array for the third generation industrial computed tomography was also developed.
Źródło:
Nukleonika; 2009, 54, 2; 129-133
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
X-ray techniques in the investigation of a Gothic sculpture : the risen Christ
Autorzy:
Mikołajska, A.
Walczak, M.
Kaszowska, Z.
Urbańczyk-Zawadzka, M.
Powiązania:
https://bibliotekanauki.pl/articles/146866.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
cultural heritage
X-ray image
X-ray dual source computed tomography (DSCT)
scanning electron microscopy energy dispersed X-ray spectroscopy (SEM-EDX)
Opis:
For over a century, X-ray radiation has played an important role in the area of the conservation and restoration of cultural heritage objects. X-ray techniques are amongst the most fundamental and helpful methods used in the investigation of art works. This paper reviews the application of traditional radiography, X-ray dual source computed tomography (DSCT) and scanning electron microscopy combined with energy dispersed X-ray spectroscopy (SEM-EDX) to the investigation of a wooden, Gothic sculpture, The risen Christ. Thanks to the properties of X-ray radiation (different absorption by various materials) first two methods allow the assessment of the preservation state and the observation of the internal structure of an object in 3-D. While SEM-EDX analysis permits the elemental analysis of the polychrome layers. As a result 2-D and 3-D images, permitting the full volume inspection of an object, were taken in a totally non-destructive way. The morphological and physical information about the inner structure of the investigated wooden sculpture was obtained, revealing changes related to previous restorations, as well as ageing effects. Employing the SEM-EDX, painting materials (pigments and filers), were identified. Gained data is essential for restorers to understand the whole structure of the studied object and to decide which further investigation and restoration steps have to be undertaken.
Źródło:
Nukleonika; 2012, 57, 4; 627-631
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-14 z 14

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