Comparison of doses and quality of x-ray images at selected examinations among general radiological departments in Slovenian medical institutions

Uvod: Rentgensko slikanje prsne hrbtenice, ledvene hrbtenice in kolka spada med najpogostejše preiskave rentgenske diagnostike. Ob primerjavi različnih parametrov pri slikanju omenjenih projekcij zagotovimo kakovostnejšo radiološko prakso. Namen: Namen magistrske naloge je primerjava doz in rentgenskih slik med slovenskimi zdravstvenimi ustanovami. Cilj je bil ugotoviti ali med zdravstvenimi ustanovami obstajajo razlike pri primerjavi ekspozicijskih pogojev, vrednosti DAP, efektivne doze, doze na posamezne organe in kakovosti rentgenskih slik. Metode dela: Raziskava je potekala v treh delih. V prvem delu smo uporabili eksperimentalno metodo in pri tem izvajali meritve v 16-ih slovenskih zdravstvenih ustanovah. Drugi del je zajemal analitično študijo, pri kateri smo analizirali zbrane podatke. V tretjem delu smo s pomočjo CNR vrednosti ocenjevali rentgenske slike in jih primerjali z prejeto dozo ionizirajočega sevanja. Rezultati: Pri slikanju prsne hrbtenice v AP in STR projekciji se v 37% slikanj vrednosti izbrane anodne napetosti nahaja izven evropskih smernic. Pri slikanju ledvene hrbtenice (Fantom 1 in Fantom 2) so bile v AP in STR projekciji uporabljene iste vrednosti anodne napetosti. Zato je pri AP projekciji v obeh primerih (Fantom 1 in Fantom 2) 33,3% izbranih vrednosti tistih, ki se nahajajo izven referenčnega intervala. Enako velja za STR projekcijo.V tem primeru odstopata le dva rentgenska aparata, kar znaša 7,4% vseh vrednosti. Pri slikanju kolka je v AP projekciji 33,3% meritev izven referenčnega intervala (70-80kV). Tretji kvartil vrednosti DAP za slikanje prsne hrbtenice je v AP projekciji 16,2µGym2, v STR projekciji pa 10,4µGym2. Pri slikanju ledvene hrbtenice (Fantom 1) v AP projekciji znaša tretji kvartil vrednosti DAP 64µGym2 in pri STR 122,2µGym2. Pri fantomu 2 pri slikanju ledvene hrbtenice v AP projekciji tretji kvartil predstavlja vrednost 80µGym2, za STR projekcijo pa 94µGym2. Vrednost tretjega kvartila pri slikanju kolka v AP projekciji znaša 42,3 µGym2. Razprava in zaključek: Ugotovili smo, da obstajajo razlike pri ekspozicijskih pogojih, DAP vrednostih, efektivni dozi, dozi na posamezne organe in kakovosti rentgenskih slik med slovenskimi zdravstvenimi ustanovami. Nobena izmed vrednosti DAP in VKD vrednosti ne presega predpisanih diagnostičnih referenčnih ravni. Enako velja za efektivno dozo, ki v nobenem primeru ne presega priporočenih vrednosti. Pri primerjavi ocene kakovosti slike (CNR) z vrednostjo DAP ugotovimo, da iz vrednosti DAP ne moremo sklepati o kakovosti rentgenske slike.Introduction: X-ray imaging of thoracic spine, lumbar spine and hip are among most common diagnostic x-ray imaging examinations. Comparison of imaging parameters of said examinations provides a higher quality of radiologic practice. Purpose: Purpose of thesis is the comparison of dose and x-ray images among Slovenian medical institutions. The goal was establishing whether there are differences among medical institutions regarding exposure parameters, dose area product, effective dose, organ specific dose and image quality. Methods: Research had 3 main parts. First part was an experimental method where we measured specific parameters in 16 Slovenian medical institutions. Second part was an analytical study where we analysed gathered data. Third part consisted of evaluation of x-ray images using CNR values and comparing them to received dose of ionising radiation. Results: With AP and lateral images of thoracic spine 37% of selected tube potentials were outside of European guidelines. With lumbar spine imaging (Phantom 1 and Phantom 2) tube potentials were the same for AP and lateral images. This is why 33,3% of values differ from the frame of reference in both cases. The same applies to lateral images. In this case only two of the x-ray machines differ, which represents 7,4% of all values. With AP imaging of the hip 33,3% of values fall outside of frame of reference (70 - 80 kV). According to our measurements the third quartile for DAP was 16,2μGym² for thoracic spine (AP projection) and 10,4μGym² for lateral projection. For imaging of lumbar spine in the case of Phantom 1 the third quartile for DAP was 64μGym² (AP projection) and 122,2μGym² for lateral projection. In the case of Phantom 2 it measures at 80μGym² (AP projection) and 94μGym² for lateral projection. For the AP projection of the hip the third quartile for DAP was 42,3μGym². Discussion and conclusion: We found that there are differences with exposure parameters, dose area product, effective dose, organ specific dose and image quality among Slovenian medical institutions. None of the DAP or entrance surface dose values are above set diagnostic referential levels. The same is true for effective dose, which in none of the cases exceeds the recommended dose. In comparison of image quality (CNR) with dose area product values, we established that higher or lower dose does not mean better or poorer image quality