Primerjava dozne obremenitve pri slikanju skolioze v anteroposteriorni in posteroanteriorni projekciji - študija na fantomu : diplomsko delo

Homar, Klara (author), Zavodnik, Katja (author), Starc, Tina (mentor), Mekiš, Nejc (comentor)

Uvod: Slikanje skolioze spada med visokodozne preiskave, ker zajema kar nekaj radiosenzitivnih organov in v večini primerov zajema mlajšo populacijo. Namen: Namen diplomske naloge je bil ugotoviti, ali obstajajo razlike v dozni obremenitvi pacienta glede na položaj slikanja (anteroposteriorna ali posteroanteriorna projekcija). Metode dela: Raziskavo smo izvedli na fantomu. Naredili smo 20 rentgenogramov, pri čemer smo fantom slikali 5-krat v AP projekciji in 5-krat v PA projekciji za področje vratne in prsne hrbtenice do 10. prsnega vretenca, nato pa smo postopek 10-krat ponovili še za področje ledvene hrbtenice. Vsako meritev smo ponovili petkrat, pri čemer smo pred vsako meritvijo fantom in dozimeter na novo postavili zato, da smo v meritev vključili napako zaradi postavitve aparata, fantoma in dozimetra. Rezultati: Iz pridobljenih rezultatov lahko razberemo, da sta DAP in VKD višji pri PA projekciji. V vratnem in prsnem predelu slikanja znaša razlika pri VKD 24,8 % v prid AP projekciji, enako je tudi pri slikanju ledvenega predela, kjer je v PA projekciji VKD večja za 17,8 %. Efektivna in absorbirana doza na organe pa sta v PA projekciji nižji, kar pa je najpomembneje. Efektivna doza prikazuje statistično značilne razlike med AP in PA projekcijo slikanja. Pri uporabi PA projekcije je v vratnem in prsnem predelu ta razlika znašala 75 %, v ledvenem predelu pa je razlika povprečnih efektivnih doz za 25 % manjša. Absorbirana doza se je v PA projekciji zmanjšala približno za polovico. Razprava in sklep: Rezultati raziskave so pokazali, da je izbira PA projekcije za slikanje celotne hrbtenice skolioze metoda izbora. Pri PA projekciji ležijo radioobčutljivi organi bližje slikovnemu sprejemniku in tako prejmejo nižjo dozo, v AP projekciji pa so le-ti bolj izpostavljeni sevanju. Ugotovili smo, da je efektivna doza v PA projekciji nižja kot v AP projekciji, kljub temu da je VKD v PA projekciji večja kot v AP projekciji. Razlog za to je položaj hrbtenice, ki je v PA projekciji bližje izvoru rentgenskih žarkov, radiosenzitivni organi pa ležijo bližje stativu in na ta način prejmejo nižjo dozo, ker se veliko žarkov absorbira že v hrbtenici.

• Language: Slovenian
• Keywords: skolioza, rentgensko slikanje skolioze, ledvena hrbtenica, radiosenzitivni organi, AP in PA projekcija, zmanjšanje doze
• Work type: Bachelor thesis/paper
• Organization: ZF - Faculty of Health Sciences
• Year: 2018
• PID: 20.500.12556/RUL-102536
• COBISS.SI-ID: 5473131
• Publication date in RUL: 01.09.2018

Secondary language

• Language: English
• Title: Comparison of dose in scoliosis imaging in anteroposterior and posteroanterior projection - study on phantom : diploma work

Abstract

Introduction: The X-ray of scoliosis is a high-dose research because it involves quite a few radiosensitive organs. At the PA projection, the radiosensitive bodies lie closer to the image receiver, thus receiving a lower dose. In the AP projection, they are more exposed to radiation. Aim: The purpose of the thesis is to determine whether there are differences in the dosage load relative to the position of imaging (the AP or the PA projection) and what the dose for the selected radio sensing organs in both of these projections is. Method: We conducted the survey on the phantom. We made 20 X-ray diagrams where we photographed the phantom 5 times in the AP projection and 5 times in the PA projection for the area of the neck and chest spine to the 10 thoracic vertebrae. We then repeated the procedure for the lumbar spine. Each measurement was repeated five times. Before each measurement, the phantom, and the dosimeter were repositioned beforehand in order to include the error in the measurement due to the installation of the apparatus, the phantoms and the dosimeter. Results: We can see from the results that the input skin dose and DAP are higher in the PA projection. In the neck and chest area of the imaging, the difference in input skin dose is 24.8 % in favor of the AP projection and the same as in the lumbar region where the PA projection of VKD is 17.8 % higher. The effective dose and absorbed dose are lower in the PA projection and that is the most important. The effective dose shows the statistically significant difference between the AP and the PA projection. When using PA projections, this difference was 75 % in the neck and chest area, and in the lumbar region, the difference in mean effective doses was 25 % lower. The absorbed dose in the PA projection decreased by about half. Discussion and conclusion: The results have shown that the choice of the PA projection for imaging the entire scoliosis is the selection method. We found that the effective dose in the PA projection is lower than in the AP projection. However, the VKD in the PA projection is bigger than in the AP projection. The reason for this is the position of the spine which is closer to the source of x-rays in the PA projection. In addition, the radiosensitive organs lie closer to the tripod. Thus they receive a lower dose because many rays are already absorbed in the spine.

• Keywords: scoliosis, X-ray of scoliosis, lumbar spine, radiosensitive organs, AP and PA projection, dose reduction