Vpliv zaslanjanja primarnega polja na prejeto dozo pri izbranih preiskavah v splošni radiografiji : magistrsko delo

Vičar, Špela (author), Mekiš, Nejc (mentor), Alukić, Erna (comentor), Škrk, Damijan (reviewer)

Uvod: Sevalna zaščita je eden temeljnih principov v radiološki diagnostiki. Optimalno zaslanjanje primarnega slikovnega polja je ključno za zmanjšanje nepotrebne izpostavljenosti pacientov ionizirajočemu sevanju, vendar v klinični praksi še vedno prihaja do prekomernega večanja slikovnega polja, kar vpliva na višanje doze za radiosenzitivne organe in efektivno dozo. Namen: Namen raziskave je bil oceniti uporabo optimalnega zaslanjanja v izbrani bolnišnici ter raziskati njegov vpliv na dozne parametre pri rentgenskem slikanju vratne in ledvene hrbtenice ter prsnih organov. Metode dela: Raziskavo smo izvedli v Splošni bolnišnici dr. Jožeta Potrča Ptuj na dveh rentgenskih aparatih (Siemens Multitom Rax, aparat 1 in Siemens Ysio Max, aparat 2). Skupno smo izvedli 1200 meritev na aparatu 1 in 1120 na aparatu 2. Pri vsaki preiskavi smo uporabili enako velik vzorec pacientov z optimalnim in neoptimalnim zaslanjanjem. Zabeležili smo maso in višino pacientov, ekspozicijske pogoje, produkt doze in površine – DAP in velikost primarnega polja ter ovrednotili, ali je bilo zaslanjanje izvedeno optimalno. S programom PCXMC 2.0 smo izračunali efektivno in absorbirano dozo na sosednje organe. Rezultati: Pri vratni hrbtenici se je v AP smeri z zmanjšanjem velikosti primarnega polja do 74,37 % DAP znižal do 81,03 % in efektivna doza do 31,58 %. V stranski smeri pa je manjše polje (do 61,29 %) vplivalo na znižanje DAP do 60,50 % in efektivne doze do 41,9 %. Pri ledveni hrbtenici se je primarno polje ob optimalnem zaslanjanju v AP smeri zmanjšalo do 27,14?%, DAP do 56,98?% in efektivna doza do 55,47 %. V stranski smeri pa polje do 30,56?%, DAP do 41,05?% in efektivna doza do 42,26 %. Pri prsnih organih je bilo optimalno polje v PA smeri manjše do 10,54 % in DAP do 26,58 %. V stranski smeri je bilo optimalno polje manjše do 14,53 % in DAP do največ 26,58 %. Efektivna doza je bila pri optimalnem polju v stranski smeri nižja do največ 49,14 %, v PA smeri na aparatu 1 do 18,26 %. Na aparatu 2 v PA smeri pa je bila nekoliko nižja pri neoptimalno zaslonjenem polju (2,34 %), brez statistične značilnosti. Razprava in zaključek: Optimalno mehansko zaslanjanje je dokazano znižalo dozne parametre in obremenitev radiosenzitivnih organov. Rezultati potrjujejo potrebo po dosledni uporabi optimalnega zaslanjanja v klinični praksi, saj elektronsko obrezovanje ne more nadomestiti fizičnega zaslanjanja.

• Language: Slovenian
• Keywords: magistrska dela, radiološka tehnologija, DAP, doza, efektivna doza, FOV, optimalno, primarno slikovno polje, radiosenzitivni organi, zaslanjanje
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: ZF - Faculty of Health Sciences
• Place of publishing: Ljubljana
• Publisher: [Š. Vičar]
• Year: 2025
• Number of pages: 117, [6] str.
• PID: 20.500.12556/RUL-175125
• UDC: 616-07
• COBISS.SI-ID: 253576963
• Publication date in RUL: 17.10.2025

Secondary language

• Language: English
• Title: The impact of the primary beam size on the radiation dose for selected procedures in general radiography : master thesis

Abstract

Introduction: Radiation protection is one of the fundamental principles in radiological diagnostics. Optimal collimation of the primary X-ray field is essential for reducing unnecessary patient exposure to ionising radiation. However, in clinical practice, excessive field enlargement still occurs, resulting in higher doses to radiosensitive organs and increased effective dose. Purpose: The purpose of this study was to evaluate the use of collimation in a selected hospital and to investigate its impact on dose parameters during radiographic imaging of the cervical spine, lumbar spine, and chest. Methods: The study was conducted at the General Hospital dr. Jožeta Potrča Ptuj on two X-ray units (Siemens Multitom Rax, device 1 and Siemens Ysio Max, device 2). In total, 1200 measurements were performed on device 1 and 1120 on device 2. For each examination, equal sample sizes of patients were included for optimal and non-optimal collimation. Patient weight and height, exposure conditions, Dose Area Product – DAP, and field size – FOV were recorded, and images were evaluated for collimation adequacy. Effective dose and organ doses were calculated using the PCXMC 2.0 program. Results: For the cervical spine, reducing the FOV by up to 74.37 % in the AP projection lowered DAP by up to 81.03 % and effective dose by 31.58 %. In the lateral projection, reducing FOV by up to 61.29 % decreased DAP by 60.50 % and effective dose by 41.9 %. For the lumbar spine, optimal collimation reduced FOV in the AP projection by up to 27.14 %, DAP by 56.98 %, and effective dose by 55.47 %. In the lateral projection, FOV reduction of up to 30.56 % resulted in a DAP decrease of 41.05 % and an effective dose reduction of 42.26 %. For chest imaging, the PA projection showed a reduction of FOV by up to 10.54 % and DAP by 26.58 % while in the lateral projection FOV was reduced by up to 14.53 % and DAP by 26.58 %. Effective dose was lower with optimal collimation in the lateral projection by up to 49.14 % and in the PA projection on device 1 by 18.26 %. On device 2 in the PA projection, effective dose was slightly lower with non-optimal collimation (2.34 %), without statistical significance. Discussion and Conclusion: The study confirmed that mechanical collimation significantly reduced dose parameters and radiation burden to radiosensitive organs. Results support the need for consistent use of collimation in clinical practice, as electronic cropping cannot substitute for physical collimation.

• Keywords: master's theses, radiologic technology, DAP, dose, effective dose, FOV, optimal, primary X-ray field, radiosensitive organs, collimation