Doza, ki jo prejme pacient pri slikanju ledvene hrbtenice pri horizontalnem poteku centralnega žarka : diplomsko delo

Ropič, Anja (author), Širovnik, Nina (author), Mekiš, Nejc (mentor), Fujan, Maja (comentor), Medič, Mojca (reviewer)

Uvod: Rentgensko slikanje ledvene hrbtenice je ena izmed najpogostejših preiskav v splošni radiografiji, pri kateri bolnik prejme relativno visoko dozo ionizirajočega sevanja. Doza ionizirajočega sevanja, ki jo dobi pacient pri stranski projekciji ledvene hrbtenice, je opisana kot ekvivalent 50 slikanj prsnega koša Namen: Namen diplomskega dela je bil ugotoviti, kako oddaljenost pacienta od slikovnega sprejemnika vpliva na dozo, ki jo prejme pacient pri stranskem slikanju ledvene hrbtenice pri horizontalnem poteku centralnega žarka. Metode dela: Raziskavo smo izvedli v dveh delih. V prvem delu naloge smo merili doze na dveh antropomorfnih fantomih ledvene hrbtenice PBU 60 in RS-113T z različnimi atenuacijskimi koeficienti v treh različnih položajih. V drugem delu naloge smo doze ionizirajočega sevanja primerjali glede na različne atenuacijske koeficiente prej omenjenih fantomov, ter ugotovili ali se doza spreminja glede na priležnost slikovnega sprejemnika k pacientu oz. fantomu. Na obeh fantomih smo odčitali izmerjeno vrednost produkta doze in površine (DAP). Prav tako smo izračunali vstopno kožno dozo (VKD), efektivno dozo (E), SNR, CNR in dozo ionizirajočega sevanja na organe. Rezultati: V raziskavi smo dokazali statistično značilne razlike v dozi ionizirajočega sevanja pri slikanju ledvene hrbtenice pri vseh treh položajih, ki smo jih izvajali ter pri obeh antropomorfnih fantomih PBU 60 in RS-113T. Vrednosti DAP, VKD ter efektivne doze so bili pri obeh fantomih, torej PBU 60 ter RS-113T najmanjše pri položaju kjer je slikovni sprejemnik ob mizi, fantom ob slikovnem sprejemniku (položaj 3), največje pa pri položaju kjer je slikovni sprejemnik v osnovnem položaju, fantom na sredini preiskovalne mize (položaj 1). Razlika v DAP-u med omenjenima položajema pri fantomu PBU 60 je 25,15 ?Gy m2, pri fantomu RS-113T pa 122,97 ?Gy m2. Razlika v VKD med omenjenima položajema pri fantomu PBU 60 je 5,21 mGy, pri fantomu RS-113T pa 11,98 mGy. Razlika v efektivni dozi med omenjenima položajema pri fantomu PBU 60 je 42,72 ?Sv, pri fantomu RS-113T pa 144,76 ?Sv. Razprava in zaključek: V naši raziskavi je bilo dokazano da oddaljenost pacienta od slikovnega sprejemnika vpliva na dozo ionizirajočega sevanja. Razlika v povprečju med položajem 3 in položajem 1 pri fantomu PBU 60 za DAP je 23,1 %, VKD 62,5% in efektivna doza 25,0 %. Razlika v povprečju med položajem 3 in položajem 1 pri fantomu RS-113T za DAP je 45,4 %, VKD 75,2 % in efektivna doza 47,4 %. Za nadaljnje raziskave v prihodnosti priporočamo optimizacijo ekspozicijskih pogojev, pri posameznem položaju ter izvedbo meritev na pacientih.

• Language: Slovenian
• Keywords: diplomska dela, radiološka tehnologija, ledvena hrbtenica, stranska projekcija, doza ionizirajočega sevanja, horizontalen potek žarka, optimizacija protokola
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: ZF - Faculty of Health Sciences
• Place of publishing: Ljubljana
• Publisher: [A. Ropič, N. Širovnik]
• Year: 2021
• Number of pages: 31 str., [3] str. pril.
• PID: 20.500.12556/RUL-130427
• UDC: 616-07
• COBISS.SI-ID: 76446723
• Publication date in RUL: 15.09.2021

Secondary language

• Language: English
• Title: Dose recieved by the patient when the lumbar spine is imaged with a horizontal course of the central beam : diploma work

Abstract

Introduction: X-ray imaging of the lumbar spine is the most common examination in general radiography, in which the patient has a relatively high dose of ionizing radiation. The dose of ionizing radiation recieved by the patient from the lateral projection of the lumbar spine is described as the equivalent of 50 chest imaging. Purpose: The purpose of this diploma work was to determine how the distance of the patient from the image reciever affects the dose recieved by the patient in lateral imaging of the lumbar spine, in the horizontal course of the central beam. Methods: The research was conducted in two parts. In the first part of the thesis, doses were measured on two anthropomorphic lumbar spine phantoms PBU 60 and RS-113T with different attenuation coefficients in three different positions. In the second part of the task, the doses of ionizing radiation were compared according to different attenuation coefficients of the previously mentioned phantoms, and it was determined whether the dose changes according to proximity of the image reciever to the patient or to the phantom. Measured dose and surface area (DAP) values were read on both phantoms. We also calculated the input skin dose (VKD), effective dose (E), SNR, CNR and dose of ionizing radiation to the organs. Results: In the study, we demonstrated statistically significant differences in the dose of ionizing radiation in the imaging of the lumbar spine in all three positions with both anthropomorfic phantoms PBU 60 and RS-113T. The values of DAP, VKD and effective dose were the lowest in both phantoms PBU 60 and RS-113T in the position where the image reciever is by the table, the phantom next to the image reciever (position 3), and the highest in the position where the image reciever is in the basic position, phantom in the middle of the examination table (position 1). The difference in DAP between theese two positions in the PBU 60 phantom is 25.15 µGy m2, and in the RS-113T phantom 122.97 µGy m2. The difference in VKD between theese two positions in the PBU 60 phantom is 5.21 mGy, and in the RS-113T phantom 11.98 mGy. The difference in effective dose between theese two positions in the phantom PBU 60 is 42.72 µSv, and in the phantom RS-113T 144.76 µSv. Discussion and conclusion: In our study, we demonstrated that the distance of the patient from the image reciever effects the dose of ionizing radiation. The mean difference in phantom PBU 60 between position 3 and position 1 for DAP is 23.1 %, for VKD 62.5 % and for effective dose 25.0 %. The mean difference in phantom RS-113T between position 3 and position 1 for DAP is 45.4 %, for VKD 75.2 % and for effective dose 47.4 %. For further research in the future, we recommend optimization of exposition protocol at each positions and the measure performance on patients.

• Keywords: diploma theses, radiologic technology, lumbar spine, lateral projection, dose of ionizing radiation, horizontal beam course, protocol optimization