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Uvod: Rentgensko slikanje je proces, kjer z uporabo ionizirajočega sevanja oziroma rentgenske svetlobe prikažemo želeni organ ali del telesa. Ionizirajoče sevanje lahko povzroči škodljive učinke na zdravje izpostavljene osebe, zaradi tega uporabljamo različne načine, da bi prejeto dozo izpostavljene osebe zmanjšali. Namen: Z diplomsko nalogo smo želeli ugotoviti, kako sprememba anodne napetosti in uporaba dodatne filtracije aluminija in bakra, vpliva na dozo pacienta pri slikanju pljuč v dveh projekcijah. Metode dela: Izvedli smo slikanje pljuč v PA in stranski projekciji z lastno filtracijo rentgenske cevi, nato smo dodajali dodatne filtre iz bakra in aluminija. Pri tem smo merili produkt doze in površine slikovnega polja (DAP). Izračunali smo še efektivno dozo (ED) in dozo na organe s programom PCXMC 2.0, ki uporablja Monte Carlo simulacijo. To smo naredili z namenom, da ugotovimo zvezo med DAP-om in efektivno dozo ter dozo na organe. Rezultati: Na podlagi rezultatov meritev smo ugotovili, da se ob povečevanju anodne napetosti, poveča tudi DAP. Ugotovili smo tudi, da se ob povečevanju debeline dodatne filtracije bakra, DAP zmanjša, doza na organe pa se poveča. Prav tako se prispevek k efektivni dozi poveča. Največ doze v PA projekciji prejmejo pljuča, požiralnik, nadledvične žleze in vranica. Največ doze v stranski projekciji prejmejo dojke, nadledvične žleze in vranica. Najmanj doze v obeh projekcijah prejmejo jajčniki in moda. Pri računanju prispevkov k efektivni dozi, smo ugotovili, da največ k efektivni dozi prispevajo pljuča in nadledvične žleze v PA projekciji, ter pljuča, dojke, vranica in želodec v stranski projekciji. Razprava in zaključek: Z diplomsko nalogo smo dokazali, da se ob večanju anodne napetosti veča tudi DAP. Prav tako smo dokazali, da se ob uporabi večje debeline dodatne filtracije DAP zmanjšuje, doza na organe pa se povečuje. Pri PA projekciji se je ED, ob uporabi dodatne filtracije Cu, pri 0,1 mm povečala, pri 0,2 mm in 0,3 mm pa zmanjšala. Pri stranski projekciji pa se je povečala pri 0,1 mm in 0,2 mm, pri 0,3 mm pa se ni bistveno spremenila. Ob podanih podatkih meritve lahko zaključimo, da bi dodatno filtracijo bilo smiselno uporabljati z ozirom na dozo sevanja, ki jo prejme pacient. Introduction: X-ray imaging is a process where the desired organ or part of the body is shown using ionizing radiation or X-rays. Ionizing radiation can cause harmful effects on the health of the exposed person, therefore we use various methods to reduce the received radiation dose. Purpose: With this diploma thesis, we want to find out how the change of tube voltage and use of additional filtration of aluminum and copper, affects the patient's dose when imaging the lungs in two projections. Methods: We performed PA lung imaging and lateral projection with the inherent X-ray tube filtration, after which additional copper and aluminum filters were added. The product of dose and surface area of the image field (DAP) was measured. Also, we calculated the effective dose and the dose to the organs with the PCXMC 2.0 program, which uses the Monte Carlo simulation. This was done in order to determine if there are any relations between the DAP and the effective dose and the dose to the organs. Results: Based on the measurement results, we found that DAP also increases by increaseing the tube voltage. We also found that as the thickness of the additional copper filtration increases, DAP decreases, while the dose to the organs increases. The contribution to the effective dose is also increased. The lungs, esophagus, adrenal glands, and spleen receive the highest doses in the PA projection. The breast, adrenal glands and spleen receive the highest doses in lateral projection. Meanwhile, the ovaries and testicles receive the least dose in both projections. When calculating the contributions to the effective dose, we found that the lungs and adrenal glands in the PA projection, and the lungs, breast, spleen and stomach in the lateral projection contribute the most to the effective dose. Discussion and conclusion: With the diploma thesis we proved that DAP increases by increasing the tube voltage. We have also shown that using a greater thickness of additional filtration reduces DAP and increases the dose to the organs. In the PA projection, ED was increased at 0,1 mm using additional Cu filtration, while it was decreased at 0,2 mm and 0,3 mm filtration. In the lateral projection, however, it increased at 0,1 mm and 0,2 mm, but did not change significantly at 0,3 mm. In the lateral projection, DAP and the dose on the organs increase. Given the measurement data, we can conclude that the use of additional filtration would make sense, with regard to the radiation dose received by the patient. |
