Analiza vpliva debeline pacienta pri rentgenskem slikanju medenice na prejeto dozo in kakovost slike : magistrsko delo

Kisilak, Tanja (avtor), Mekiš, Nejc (mentor), Dolenc, Laura (komentor), Škrk, Damijan (recenzent)

Uvod: Rentgensko slikanje medenice je ena najpogosteje uporabljenih preiskav v splošni radiografiji in spada med najbolj dozno obremenjujoče preiskave. Zaradi naraščajočih težav s prekomerno telesno težo in debelostjo je pomembno prilagoditi protokole slikanja, da se ujame ravnotežje med kakovostjo slike in prejeto dozo sevanja pri močnejših pacientih. Namen: Namen raziskave je preučiti vpliv povečane debeline telesa v predelu medenice na ekspozicijske pogoje, kakovost slike in prejeto dozo (DAP, efektivno dozo in dozo na izbrane organe) pri rentgenskem slikanju medenice. Metode dela: Raziskava je bila izvedena v dveh delih. Prvi del je obsegal meritve na fantomu, z dodajanjem plasti živalske maščobe do debeline 15 cm za simulacijo povečane debeline telesa. Izmerjeni so bili DAP, velikost polja, tokovni sunek (mAs), anodna napetost (kV) ter razdalja med goriščem in objektom, iz katerih smo izračunali efektivno dozo. V drugem delu so bile meritve izvedene na 100 pacientih, napotenih na rentgensko slikanje medenice in naključno razdeljenih v dve skupini. Ena skupina je bila slikana po trenutnem protokolu (81 kV), druga pa po novem (85 kV). Pri vseh so bile izmerjene telesna višina in masa, DAP, velikost polja, razdalja med goriščem in objektom, tokovni sunek (mAs) in anodna napetost (kV). Iz meritev so bili izračunani debelina predela, indeks telesne mase in efektivna doza. V obeh delih smo kakovost rentgenogramov objektivno ocenili s SNR in CNR. Rezultati: Rezultati meritev na fantomu so pokazali, da se DAP in efektivna doza povečujeta z naraščajočo debelino maščobe pri nespremenjeni anodni napetosti, medtem ko se ob povišanju anodne napetosti pri enaki debelini maščobe DAP in efektivna doza eksponentno zmanjšujeta. Višja debelina maščobe poslabšuje SNR in CNR, a ti ostaneta nad optimalno vrednostjo. V drugi fazi raziskave na pacientih smo ugotovili, da je nov protokol zmanjšal povprečno vrednost DAP za 7,6 %, vendar razlika ni bila statistično značilna (p = 0,280). Prav tako se je efektivna doza z novim protokolom zmanjšala za 4,1 %, vendar je tudi ta razlika statistično neznačilna (p = 0,413). Kakovost slike se med obema protokoloma ni statistično značilno razlikovala niti pri SNR (p = 0,165) niti pri CNR (p = 0,124). Največjo povprečno dozo so prejeli testisi. Kljub opaznim razlikam v dozah med organi, ni bilo statistično značilnih razlik med protokoloma za noben organ. Razprava in zaključek: Debelina predela telesa vpliva na DAP, efektivno dozo in objektivno kakovost slike. Pri rentgenskem slikanju pacientov z večjo debelino predela telesa, je priporočljivo razmisliti o uporabi višjih anodnih napetosti, da se zmanjša izpostavljenost sevanju in ohrani optimalna kakovost slike.

• Jezik: Slovenski jezik
• Ključne besede: magistrska dela, radiološka tehnologija, rentgensko slikanje medenice, debelina telesa, doza, kakovost slike
• Vrsta gradiva: Magistrsko delo/naloga
• Tipologija: 2.09 - Magistrsko delo
• Organizacija: ZF - Zdravstvena fakulteta
• Kraj izida: Ljubljana
• Založnik: [T. Kisilak]
• Leto izida: 2024
• Št. strani: 59 str., [6] str. pril.
• PID: 20.500.12556/RUL-165303
• UDK: 616-07
• COBISS.SI-ID: 217172995
• Datum objave v RUL: 30.11.2024

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Analysis of patient thickness in pelvic radiography and its impact on radiation dose and image quality : master thesis

Izvleček

Introduction: Pelvic radiography is one of the most commonly used examinations in general radiography and is one of the most dose-intensive examinations. Due to the increasing problems of overweight and obesity, it is important to adjust protocols to capture the balance between image quality and radiation dose received in overweight patients. Purpose: The aim of the study was to determine the effect of increased body thickness in the pelvic region on the exposure conditions, image quality and dose received (DAP, effective dose and dose to selected organs) in pelvic radiography. Methods: The study was divided into two parts. The first part consisted of measurements on a phantom, adding a layer of animal fat up to 15 cm thick to simulate increased body thickness. The DAP, primary field size, mAs, kV and source-to-skin distance were measured, from which the effective dose was calculated. In the second part, measurements were conducted on 100 patients referred for pelvic radiography and randomly divided into two groups. One group was imaged using the current protocol (81 kV) and the other group was imaged using the new protocol (85 kV). Body height and mass, DAP, primary field size, source-to-skin distance, mAs and kV were measured in all patients. Body part thickness, BMI and effective dose were calculated from the measurements. In both parts, the quality of the radiographs was objectively evaluated by SNR and CNR. Results: The results of the phantom measurements showed that DAP and effective dose increase with increasing fat thickness at constant anodic voltage, while DAP and effective dose decrease exponentially with increasing anodic voltage at the same fat thickness. Higher fat thickness decreases SNR and CNR, but these remain above the optimum value. In the second phase of the patient study, we found that the new protocol decreased DAP by 7.6%, but the difference was not statistically significant (p = 0.280). Also, the effective dose decreased by 4.1% with the new protocol, but this difference was again not statistically significant (p = 0.413). The difference in image quality between the two protocols was not statistically significant for either SNR (p = 0.165) or CNR (p = 0.124). The testicles received the highest mean dose. Despite the noticeable differences in doses between organs, there were no statistically significant differences between the protocols for any organ. Discussion and conclusion: The thickness of the pelvic region affects the DAP, the effective dose and the objective image quality. When x-ray imaging patients with a higher body part thickness, it is recommended to consider the use of higher anode voltages to reduce radiation exposure and maintain optimal image quality.

• Ključne besede: master's theses, radiologic technology, pelvis, body part thickness, dose, image quality