Primerjava protokola računalniške tomografije glave na različnih CT aparatih v UKC Ljubljana: Povezava med dozno obremenitvijo in kakovostjo slike: študija na fantomu : magistrsko delo

Novšak, Vesna (author), Žibert, Janez (mentor), Mišič, Jure (comentor), Mekiš, Nejc (reviewer)

Uvod: Povečanje CT preiskav je poudarilo potrebo po zmanjšanju količine sevanja, ki ga povzroča. Izboljšano diagnostiko je povzročil razvoj CT tehnologije z zmanjšano količino sevanja in optimizacijo protokolov. Prejete doze sevanja morajo biti tako nizke, kot je to mogoče upoštevati, da se ob tem ohranja diagnostična kakovost slik, če se držimo načela zaščite pred sevanjem. Namen: Namen magistrskega dela je bil ugotoviti, kakšna je razlika v kakovosti slik pri SNR, SNRD, CNR in CNRD na CT aparatih treh različnih generacij v UKC Ljubljana (CT1, CT2, CT3) v primerjavi z dozno obremenitvijo s sevanjem pri preiskavi CT glave na fantomu. Metode dela: Naredili smo trideset slik, katere smo rekonstruirali brez ADMIRE rekonstrukcije na vseh treh CT aparatih, nato pa še dvajset CT rekonstrukcij slik z IR rekonstrukcijo ADMIRE na CT aparatu Siemens Drive in Siemens Force ter primerjali morebitne razlike CT aparatov v UKC Ljubljana, dozno obremenitev s sevanjem in kakovost slike na fantomu glave in kalibracijskem fantomu vode po protokolu CT spiralnega slikanja glave, ki se uporablja na vsakemu CT aparatu posebej. Na aparatu CT1 in CT2 smo primerjali morebitno razliko brez in z ADMIRE IR. Rezultati: Rezultati raziskave kažejo, da obstajajo med tremi generacijsko različnim aparati statistično značilne razlike v diagnostični kakovosti slik glede na sevalno dozo. Pri aparatoma CT1 in CT2, kjer smo primerjali razliko brez in z ADMIRE IR slik znotraj aparata pa statistično značilnih razlik nismo našli. Aparat Siemens Drive (CT2) je najbolj učinkovit glede kakovosti slik in sevalne doze DLP 619,56 mGy*cm, CTDIvol 37,85 mGy, sledi mu CT aparat Siemens FORCE (CT1), ki ima DLP 690,14 mGy*cm in CTDIvol 41,29 mGy, najslabšo kakovost in dozo sevanja pa ima CT aparat Siemens Somatom Sensation Open (CT3) z DLP 1034,51 mGy*cm in CTDIvol 62,89mGy, kar v povprečju pri fantomu glave pomeni v primerjavi s CT1 24,35% večjo dozo sevanja, glede na aparat CT2 pa 40,25% višjo dozo sevanja. Razprava in zaključek: Dokazali smo, da izbira posameznega protokola vpliva na kakovost slike. Največ zasluge pri tem ima izbira iterativne rekonstrukcije, avtomatska kontrola ekspozicije, tehnološki napredek aparata CT2 in CT1, optimizacija protokola, ki prispeva k boljši kakovosti slik z manjšo dozo sevanja.

• Language: Slovenian
• Keywords: magistrska dela, radiološka tehnologija, računalniška tomografija, optimizacija doze, doza sevanja, kakovost slike
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: ZF - Faculty of Health Sciences
• Place of publishing: Ljubljana
• Publisher: [V. Novšak]
• Year: 2023
• Number of pages: 63 str., [2] str. pril.
• PID: 20.500.12556/RUL-154491
• UDC: 616-07
• COBISS.SI-ID: 185894403
• Publication date in RUL: 17.02.2024

Secondary language

• Language: English
• Title: Comparison of head computed tomography scanning protocol on various scanners: The relationship between radiation dose and image quality: a phantom study : master thesis

Abstract

Introduction: The increase in CT scans has highlighted the need to reduce the amount of radiation it causes. Improved diagnostics has resulted from the development of CT technology with reduced radiation and optimised protocols. The radiation doses received should be as low as can be considered while maintaining the diagnostic quality of the images, provided that the principle of radiation protection. Purpose: The aim of this MSc thesis was to determine the difference in image quality of SNR, SNRD, CNR and CNRD measurements on three different generations of CT scanners at the UKC Ljubljana (CT1, CT2, CT3) compared to the radiation dose of a phantom head CT scan. Methods: Thirty images were reconstructed without ADMIRE IR on all three CT machines, followed by twenty CT reconstructions with IR ADMIRE on Siemens Drive and Siemens Force CT machines, and any differences between the CT machines in UKC Ljubljana, radiation dose and image quality were compared on the head phantom and water calibration phantom according to the head CT spiral imaging protocol used on each CT machine separately. On CT1 and CT2, we compared the potential difference without and with ADMIRE IR. Results: However, no statistically significant differences were found between CT1 and CT2, where the difference without and with ADMIRE IR within the CT1 and CT2 was compared. The Siemens Drive (CT2) is the most efficient in terms of image quality and radiation dose with a DLP of 619.56 mGy*cm and a CTDIvol of 37.85 mGy, followed by the Siemens FORCE (CT1) with a DLP of 690.14 mGy*cm and a CTDIvol of 41.29 mGy, The worst quality and radiation dose is the Siemens Somatom Sensation Open CT scanner (CT3) with a DLP of 1034.51 mGy*cm and a CTDIvol of 62.89 mGy, which means on average a 24.35% higher radiation dose for the head phantom compared to CT1 and a 40.25% higher radiation dose compared to CT2. Discussion and conclusion: The choice of iterative reconstruction, automatic exposure control, technological advances in CT2 and CT1, and optimization of the protocol contribute to better image quality with lower radiation dose.

• Keywords: master's theses, radiologic technology, computed tomography, dose optimisation, radiation dose, image quality