title: The influence of patient thickness and imaging system on patient dose and physical image quality in digital chest imaging.
abstract: The aim of this work was to study the influence of patient thickness, tube voltage and image detector on patient dose, contrast and ideal observer signal-to-noise ratio (SNR(I)), for pathological details positioned at different regions in the image in posterior-anterior (PA) chest radiology. A Monte Carlo computational model was used to compute measures of physical image quality (contrast, SNR(I)) and patient effective dose, E. Two metastasis-like details positioned in the central right lung and right lung near the spine, respectively, were studied. The tube voltage was varied between 100 and 150 kV and the patient thickness between 20 and 28 cm. Both, a computed radiography (CR) system and a direct radiography (DR) system, were investigated. The DR system provides both lower doses and better image quality compared with the CR system. The SNR(I)2/E is approximately 2.9 times higher for the DR system compared with the CR system.
authors.affiliation: Department of Radiation Physics, Linköping University, SE-581 85 Linköping, Sweden. gusul@imv.liu.se
authors.forename: Gustaf
authors.initials: G
authors.lastname: Ullman
authors.forename: Michael
authors.initials: M
authors.lastname: Sandborg
authors.forename: David R
authors.initials: DR
authors.lastname: Dance
authors.forename: Roger
authors.initials: R
authors.lastname: Hunt
authors.forename: Gudrun
authors.initials: G
authors.lastname: Alm Carlsson
mesh_terms: D016477:Artifacts; D006801:Humans; D008962:Models, Theoretical; D009010:Monte Carlo Method; D009362:Neoplasm Metastasis; D009369:Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D015588:Observer Variation; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011859:Radiography / Q000379:methods*; D013902:Radiography, Thoracic / Q000379:methods*; D012984:Software; D014963:X-Ray Intensifying Screens