Ocena frekvence nastavitve primarnega polja pri izbranih rentgenskih preiskavah v splošni radiološki diagnostiki

Hozjan, Doroteja (author), Mekiš, Nejc (mentor)

Uvod: V splošni radiološki diagnostiki je ustrezno zaslanjanje primarnega rentgenskega snopa pomemben del optimizacije, saj omejuje nepotrebno izpostavljenost pacienta in zmanjšuje količino sipanega sevanja. Pri digitalni radiografiji lahko elektronsko zaslanjanje oz. obrezovanje slike naknadno zmanjša prikazano slikovno polje in s tem prikrije dejansko velikost obsevanega področja. Namen: Namen magistrskega dela je bil oceniti učinkovitost nastavitve primarnega slikovnega polja pri izbranih rentgenskih preiskavah v splošni radiološki diagnostiki. Želeli smo ugotoviti pogostost neustreznega zaslanjanja, oceniti razlike med primarno eksponiranim in elektronsko zaslonjenim slikovnim poljem ter primerjati vrednosti produkta doze in površine (DAP) in ocenjenega nepotrebnega DAP med dobro in slabo zaslonjenimi rentgenogrami. Metode dela: Izvedli smo retrospektivno raziskavo, v katero smo vključili 603 rentgenograme vratne, torakalne in ledvene hrbtenice, rame ter kolka. Rentgenograme smo glede na odstopanje med primarno eksponiranim in elektronsko zaslonjenim slikovnim poljem razvrstili med dobro in slabo zaslonjene. Analizirali smo velikost obeh slikovnih polj, odstopanje v horizontalni in vertikalni smeri, DAP ter ocenjeni nepotrebni DAP. Podatke smo statistično analizirali s programom IBM SPSS Statistics. Rezultati: Med 603 analiziranimi rentgenogrami je bilo 444 (73,6 %) slabo in 159 (26,4 %) dobro zaslonjenih. Neustrezno zaslanjanje je prevladovalo pri vseh analiziranih projekcijah. Z elektronskim zaslanjanjem je bilo v povprečju odstranjenih 25,55 % primarno eksponiranega slikovnega polja. Pri večini projekcij so bile vrednosti DAP višje pri slabo zaslonjenih rentgenogramih, statistično značilne razlike pa smo ugotovili pri šestih od devetih primerljivih projekcij. Ocenjeni nepotrebni DAP je bil pri vseh devetih primerljivih projekcijah statistično značilno višji pri slabo zaslonjenih rentgenogramih. Razprava in zaključek: Rezultati kažejo na pogosto neustrezno nastavitev primarnega slikovnega polja in uporabo elektronskega zaslanjanja za zmanjševanje končnega prikazanega polja. Večji ocenjeni nepotrebni DAP pri slabo zaslonjenih rentgenogramih poudarja pomen ustreznega primarnega zaslanjanja pri optimizaciji izpostavljenosti pacientov. Z ustreznim zaslanjanjem lahko omejimo nepotrebno izpostavljenost pacienta, pri tem pa moramo zagotoviti prikaz vse anatomije, potrebne za diagnostično oceno. Elektronsko zaslanjanje lahko spremeni končni prikaz rentgenograma, ne more pa nadomestiti pravilne nastavitve primarnega rentgenskega polja pred ekspozicijo.

• Language: Slovenian
• Keywords: zaslanjanje, elektronsko zaslanjanje, digitalna radiografija, DAP, optimizacija
• Work type: Master's thesis/paper
• Organization: ZF - Faculty of Health Sciences
• Year: 2026
• PID: 20.500.12556/RUL-189345
• Publication date in RUL: 04.10.2026

Secondary language

• Language: English
• Title: Evaluation of the Frequency of Primary Beam Collimation in selected X-Ray Examinations in General Radiology

Abstract

Introduction: In general radiography, appropriate collimation of the primary X-ray beam is an important part of optimization, as it limits unnecessary patient exposure and reduces the amount of scattered radiation. In digital radiography, electronic collimation can subsequently reduce the displayed image field and thereby conceal the actual size of the irradiated area. Purpose: The purpose of this master's thesis was to evaluate the effectiveness of primary field collimation in selected X-ray examinations in general radiography. We aimed to determine the frequency of inadequate collimation, assess the differences between the primarily exposed and electronically collimated image fields, and compare the dose-area product (DAP) and estimated unnecessary DAP between adequately and inadequately collimated radiographs. Methods: A retrospective study was conducted, including 603 radiographs of the cervical, thoracic and lumbar spine, shoulder, and hip. Based on the deviation between the primarily exposed and electronically collimated image fields, the radiographs were classified as adequately or inadequately collimated. We analysed the size of both image fields, deviations in the horizontal and vertical directions, DAP, and estimated unnecessary DAP. Statistical analysis was performed using IBM SPSS Statistics. Results: Of the 603 analysed radiographs, 444 (73.6%) were inadequately collimated and 159 (26.4%) were adequately collimated. Inadequate collimation predominated in all analysed projections. On average, 25.55% of the primarily exposed image field was removed by electronic collimation. DAP values were higher in inadequately collimated radiographs for most projections, with statistically significant differences found in six of the nine comparable projections. Estimated unnecessary DAP was statistically significantly higher in inadequately collimated radiographs in all nine comparable projections. Discussion and conclusion: The results indicate a high frequency of inadequate primary field collimation and the use of electronic collimation to reduce the final displayed image field. The higher estimated unnecessary DAP in inadequately collimated radiographs emphasizes the importance of appropriate primary collimation in optimizing patient exposure. Appropriate collimation can limit unnecessary patient exposure while ensuring that all anatomy required for diagnostic evaluation is included. Electronic collimation can alter the final appearance of a radiograph but cannot replace appropriate primary X-ray field collimation before exposure.

• Keywords: collimation, electronic collimation, digital radiography, DAP, optimization