Naprava male površine velikog naboja za otkrivanje radioizotopa

Objective: Radionuclide imaging is used to determine the distribution of radioactively labelled radiopharmaceuticals following application to establish the anatomy affected by a variety of neoplastic, metabolic and inflammatory conditions. This is accomplished through recording radioactive emissions using a gamma camera of a SPECT system, neither of which provides high resolution. The purpose o f this investigation was to determine whether a charge-coupled device designed for intraoral radiography could be modified to detect high energy emissions made by radiopharmaceutical agents. Methods: A RadioVisioGraphy (RVG) 32000 (Trophy Radiologie, Vincennes, France) with an unsealed sensor was employed so that the scintillator could be varied. The system was further modified to be activated by a CCX timer (Trophy Radiologie, Vincennes, France) disassociated from an x-ray generator. Radionuclides tested included 125I, 133Xe, 99mTc, 1311 and 60Co. Images were attempted of metallic test objects of known outline. Images were stored in a PC-compatible computer using the proprietary software provided by Trophy Radiologie for digital dental radiography. Results: Discernible images were found with Tc-99m calibrated at 900-925 mCi. No deterioration o f the sensor occured despite the high energy of the source, hence the tungsten glass fiberoptic prism of the RVG 32000 was effective in protecting the change-coupled device (CCD) from radiation damage. Conclusions: While further studies are needed, this preliminary study shows that there is a potential fo r using small surface CCDs for the detection of radiopharmaceuticals and, hence, to better localize the distribution of deposition within small cavities such as the mouth.Ciljevi: Slikanje radionukleidima uporabljeno je da bi se odredila distribucija radioaktivno označenih radiofarmaceutskih preparata nakon njihove primjene, s namjerom da se utvrdi područje zahvaćeno tumorom, metaboličkim ili upalnim procesom. To je ostvareno tako da je biljezeno radioaktivno zračenje gama kamerom ili SPECT sustavom od kojih ni jedan ne osigurava visoku rezoluciju. Svrha ovog istraživanja bila je odrediti, da li naprava male površine velikog naboja za intraoralnu radiografiju može biti modificirana za otkrivanje zračenja jake snage stvorenog radiofarmaceutskim preparatima. Metode. Radioviziograf (RVG) naprava tipa 32000 (Trophy Radiologie, Vincennes, Francuska) s nazaštićenim senzorom rabio se, da bi se omogućilo variranje scintilatora. Sustav se i dalje modificirao da se može aktivirati putem CCX timera (Trophy Radiologie, Vincennes, Francuska) koji nije povezan s generatorom x-zraka. Testirani su radionukleidi 125I, 133Xe, 99mTc, 1311 and 60Co. Učinjene su probne slike metalnih probnih objakata poznatog obrisa. Slike su se pohranile u PC- -kompatibilnom računalu koristeći program od Trophy Radiologie za digitalnu dentalnu radiografiju. Rezultati: Vidljive slike su nađene s 99mTc kalibriranim na 900-925 mCi. Nije došlo do smanjene kakvoće senzora bez obzira na visoku energiju izvora, dakle RVG 32000 tungsten staklena fiberoptička prizma bila je efikasna u štićenju naprave male površine velikog naboja od oštećenja zračenjem. Zaključci: Iako je potrebno dalje istraživanje, ovo je preliminarno istraživanje pokazalo, da postoji mogućnost uporaba naprave male površine velikog naboja za otkrivanje radiofarmaceutika te zato do bolje lokalizacije i distribucije njihova odlaganja unutar malih šupljina poput usne šupljine

Geophysics From Terrestrial Time-Variable Gravity Measurements

In a context of global change and increasing anthropic pressure on the environment, monitoring the Earth system and its evolution has become one of the key missions of geosciences. Geodesy is the geoscience that measures the geometric shape of the Earth, its orientation in space, and gravity field. Time-variable gravity, because of its high accuracy, can be used to build an enhanced picture and understanding of the changing Earth. Ground-based gravimetry can determine the change in gravity related to the Earth rotation fluctuation, to celestial body and Earth attractions, to the mass in the direct vicinity of the instruments, and to vertical displacement of the instrument itself on the ground. In this paper, we review the geophysical questions that can be addressed by ground gravimeters used to monitor time-variable gravity. This is done in relation to the instrumental characteristics, noise sources, and good practices. We also discuss the next challenges to be met by ground gravimetry, the place that terrestrial gravimetry should hold in the Earth observation system, and perspectives and recommendations about the future of ground gravity instrumentation