Vpliv optimalnega zaslanjanja na dozo ionizirajočega sevanja pri rentgenskem slikanju ledvene in torakalne hrbtenice v splošni diagnostiki : magistrsko delo

Pažanin, Anamaria (author), Škrk, Damijan (mentor), Mekiš, Nejc (co-mentor)

Uvod: Radiografija ledvene in torakalne hrbtenice sta področji, ki sta v samem vrhu preiskav, ki povzročajo največje sevalne obremenitve v splošni radiograifiji. Z ustrezno uporabo zaslonke po navodilih podanih v literaturi lahko močno vplivamo na zmanjšanje dozne obremenitve pacientov. Namen: Namen naloge je preveriti vpliv optimalne uporabe radiografske zaslonke na obsevanost pacientov in kakovost rentgenogramov. Metode dela: V raziskavi je sodelovalo 110 pacientov napotenih na rentgensko preiskavo ledvene in 84 pacientov napotenih na rentgensko preiskavo torakalne hrbtenice. V prvem delu raziskave je polovica pacientov slikana glede na trenutni protokol zaslanjanja, ki se uporablja v Splošni bolnišnici Dubrovnik. V drugem delu raziskave je druga polovica pacientov slikana glede na smernice za optimalno zaslanjanje primarnega polja, ki so podane v strokovni literaturi. Pri vseh pacientih smo beležili maso in višino (za izračun indeksa telesne mase), ekspozicijske pogoje, DAP in velikost primarnega polja. Iz pridobljenih podatkov pa smo z uporabo programa PCXMC izračunali efektivno dozo in absorbirano dozo na posamezne organe. Na koncu sta kakovost rentgenogramov ocenila dva zdravnika radiologa in en radiološki inženir. Rezultati in razprava: Ugotovili smo, da se z optimalno uporabo zaslonke velikost primarnega polja pri slikanju ledvene hrbtenice v AP projekciji zmanjša za 35,5 % in v stranski projekciji za 40,3 %. Kot posledica tega je bilo zmanjšanje DAP vrednosti v AP projekciji za 45,7 % ter zmanjšanje efektivne doze za 47,7 %. Pri STR projekciji nismo našli statistično značilnih razlik med skupinami pri meritvah DAP–a in efektivne doze, kar je bila posledica napačne postavitve centralnega žarka pred optimizacijo zaslanjanja. Absorbirana doza na izbrane radiosenzitivne organe se je v AP projekciji zmanjšala za povprečno 40,9 % v stranski projekciji pa za 9,5 %. Z optimalno uporabo zaslonke smo pri slikanju torakalne hrbtenice ugotovili, da je velikost primarnega polja v AP projekciji manjša za 45,4 %, v stranski projekciji pa za 40,7 %. Dokazali smo tudi nižje vrednosti DAP-a pri AP projekciji za 33,5 % in pri STR za 23,3 %. Efektivno dozo smo pri AP projekciji znižali za 53,8 % ter pri STR projekciji za 29,2 %. Povprečna absorbirana doza na izbrane organe se je v AP projekciji zmanjšala za 25,7 % in v stranski projekciji za 28,4 %. Poleg tega smo pri vseh projekcijah razen pri slikanju ledvene hrbtenice v AP projekciji ugotovili, da se z optimalno uporabo zaslonke izboljša tudi kakovost rentgenograma. Zaključek: Z izvedbo raziskave smo dokazali, da z optimalno uporabo zaslonke pri slikanju ledvene in torakalne hrbtenice vplivamo na izpostavljenost pacientov. Na ta način lahko vplivamo tudi na kakovost rentgenogramov, ki jo ne samo ohranimo, ampak še izboljšamo.

• Language: Slovenian
• Keywords: ledvena hrbtenica, torakalna hrbtenica, optimalna uporaba zaslonke, zmanjšanje doze, DAP, kakovost slike
• Work type: Master's thesis/paper
• Organization: ZF - Faculty of Health Sciences
• Year: 2019
• PID: 20.500.12556/RUL-107334
• COBISS.SI-ID: 5599083
• Publication date in RUL: 30.03.2019

Secondary language

• Language: English
• Title: The influence of optimal collimation on radiation dose in lumbar and thoracic spine in general radiography : master thesis

Abstract

Introduction: Radiography of lumbar and thoracic spine are classified as examinations which cause the greatest radiation burden in classical radiography. By the optimal usage of collimator according to the instructions given in the professional literature it's possible to greatly influence the reduction of the patients dose load. Purpose: The purpose of the research is to determine the influence of the optimal usage of collimator on patient irradiation and the image quality. Methods: The study was performed on 110 patients that were referred to the lumbar spine radiography and 84 patients that were referred to the thoracic spine radiography. For the first part of the study, half of the patients were imaged with the current collimation protocol used in the General Hospital Dubrovnik. For the second part of the study, the other half of the patients were imaged with the collimation protocol mentioned in the professional literature. For each patient DAP, image field size, exposure condtions, weight and height (for calculating the body mass index) were measured. From that data using the PCXMC program the effective dose and the absorbed organ doses were calculated. At the end, the image quality was evaluated by two radiologist and one radiologic technologist. Results and discussion: With the optimal use of the collimatior for the lumbal spine radiography we found out that the size of the primary field for the AP projection was reduced by 35,5 % and the LAT projection by 40,3 %. As a consequence, DAP value was reduced by 45,7 % and the effective dose by 47,7 % for AP projection. Regarding the LAT projection we did not find statistically different results between the groups in the DAP and the effective dose measurements which was caused by the incorrect positioning of the central beam before the optimization of collimation. The absorbed dose to selected radiosensitive organs decreased in the AP projection by an average of 40,9 % and in the LAT projection by 9,5 %. With the optimal usage of collimator in the imaging of the thoracic spine we found that the size of the primary field in the AP projection was reduced by 45,4 % and in the LAT projection by 40,7 %. The study also showed reduced values of DAP for AP projection by 33,5 % and for LAT projection by 23,3 %. The effective dose was reduced by 53,8 % for AP projection and 29,2 % for LAT projection. The mean absorbed dose to the selected organs decreased by 25,7 % in the AP projection and 28,4 % in the LAT projection. In addition, in all projections, except for the AP projection of the lumbar spine, it was found that the optimal usage of collimator improves the image quality. Conclusion: By carrying out the research we have demonstrated that optimal usage of collimator in lumbar and thoracic spine imaging has an influence on patient exposure to radiation. It also affects the image quality, which is not only preseved but rather improved.

• Keywords: lumbar spine, thoracic spine, optimal use of collimator, dose reduction, DAP, image quality