Primerjava doz pri slikanju reber v anteroposteriorni in posteroanteriorni projekciji : diplomsko delo

Rajnar, Anamarija (author), Žekš, Anita (author), Medič, Mojca (mentor), Alukić, Erna (comentor), Mekiš, Nejc (reviewer)

Uvod: Rebra slikamo v anteroposteriorni, posteroanteriorni, redko v polstranski projekciji. Slikamo lahko stoje ali leže, pri slikanju pa je pomembno, da pacient ne diha, saj to lahko povzroči neostrino anatomskih struktur na rentgenogramu. Pri diagnostičnih preiskavah z ionizirajočim sevanjem se ravnamo po načelu ALARA. Doze, o katerih se pogovarjamo v radiologiji so absorbirana, efektivna in ekvivalentna doza. Praktične dozimetrične količine, ki so pogosto merjene v klasični radiologiji so vstopna kožna doza ter produkt doze in površine. Namen: Namen diplomske naloge je primerjati produkt doze in površine in efektivne doze pri slikanju reber v AP in PA projekciji ter razliko v dozni obremenitvi organov. Metode dela: V laboratoriju Zdravstvene fakultete smo slikali antropomorfni fantom z rentgenskim aparatom Multifix/Vertix, na katerem smo merili produkt absorbirane doze in ploščine slikovnega polja. Fantom smo slikali v AP in PA projekciji na preiskovalni mizi. Naredili smo 20 rentgenogramov, 10 v AP projekciji in 10 v PA projekciji. Velikost slikovnega polja je bila 35×43 cm, RGS pa 115 cm. Dozo ionizirajočega sevanja smo merili z DAP metrom. Z računalniškim programom PCXMC smo izračunali podatke o dozi na organe v prsnem košu in njegovi neposredni bližini (kostni mozeg, dojke, srce, jetra, pljuča, limfatično tkivo, požiralnik, trebušna slinavka, vranica, želodec, priželjc in ščitnica). Rezultati: Na podlagi pridobljenih rezultatov smo ugotovili, da je razlika povprečne vrednosti DAP v AP in PA projekciji 21,76 % in razlika v efektivni dozi 60,38 %, oboje v prid PA projekcije. Primerjali smo podatke o dozni obremenitvi na izbrane organe, kjer le kostni mozeg in vranica prejmeta nižjo povprečno dozo v AP projekciji, dojke, srce, jetra, pljuča, limfatično tkivo, požiralnik, trebušna slinavka, želodec, priželjc in ščitnica pa prejmejo nižjo dozo v PA projekciji. Razprava in zaključek: Dokazali smo, da je PA projekcija metoda izbora, ko želimo zmanjšati dozno obremenitev na organe, saj se izognemo direktnemu obsevanju radiosenzitivnih organov. Slikanje v PA projekciji je enostaven način za zmanjševanje doze.

• Language: Slovenian
• Keywords: diplomska dela, radiološka tehnologija, rebra, AP, PA, fantom, absorbirana doza, efektivna doza, produkt doze in površine, rentgenski aparati, dozna obremenitev
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: ZF - Faculty of Health Sciences
• Place of publishing: Ljubljana
• Publisher: [A. Rajnar, A. Žekš]
• Year: 2020
• Number of pages: 29 str.
• PID: 20.500.12556/RUL-119152
• UDC: 616-07
• COBISS.SI-ID: 27153923
• Publication date in RUL: 04.09.2020

Secondary language

• Language: English
• Title: Comparison of doses in imaging ribs anteroposterior and posteroanterior projection : diploma work

Abstract

Introduction: Ribs are scanned in an anteroposterior or posteroanterior projection, rarely also in a half-side projection. We can scan with the patient standing or laying down. While scanning, it is important for the patient not to breathe, since that can reduce the sharpness of the anatomical structures on the radiograph. When conducting diagnostic tests with ionizing radiation, we follow the ALARA principle. The doses discussed in radiology are the absorbed, effective and equivalent dose. The practical dosimetric amounts which are commonly measured in classic radiology are the entrance skin dose and the dose area product. Purpose: The purpose of this diploma work is to compare the dose area product and the effective dose when imaging the ribs in the AP or PA projections, and the difference in the doses' exposure on the organs. Methods of work: In the Faculty of Health Sciences' laboratory, we scanned an anthropomorphic phantom with the Multifix/Vertix X-ray scanner, on which we measured the dose area product and the image field's area. We scanned the phantom in the AP and PA projections on the examination table. We produced 20 radiographs, 10 in the AP projection and 10 in the PA projection. The size of the image field was 35×43 cm, with the distance of 115 cm. The dose of the ionizing radiation was measured with the DAP measurement. With the PCXMC computer program, we calculated the information about the dose exposure on the organs in the chest (bone marrow, breasts, heart, liver, lungs, limfatic tissue, esophagus, pancreas, spleen, stomach thymus and thyroid). Results: On the basis of the obtained results, we established that the difference of the average value of the dose area product in the AP and PA projections is 21,76 % and the difference in the effective dose is 60,38%, both in favour of the PA projection. We also compared the data of the dose exposure on selected organs and established that all of them received a lower dose in the PA projection, except for the bone marrow and spleen, which received a lower dose in the AP projection. Discussion and conclusion: With this diploma thesis, we showed that the PA projection is the method of choice when wanting to reduce the dose exposure on the organs, since it allows us to avoid the direct irradiation of radiosensitive organs. Scanning in the PA projection is an easy way of reducing the radiation dose.

• Keywords: diploma theses, radiologic technology, ribs, AP, PA, phantom, absorbed dose, effective dose, dose area product, x-ray, dose