Modeling granular phosphor screens by Monte Carlo methods

dc.contributor.author	Λιαπαρίνος, Παναγιώτης Φ.	el
dc.contributor.author	Κανδαράκης, Ιωάννης Σ.	el
dc.contributor.author	Κάβουρας, Διονύσης Α.	el
dc.contributor.author	Δελής, Χάρης Β.	el
dc.contributor.author	Παναγιωτάκης, Γεώργιος Σ.	el
dc.date.accessioned	2015-05-07T17:30:55Z
dc.date.available	2015-05-07T17:30:55Z
dc.date.issued	2015-05-07
dc.identifier.uri	http://hdl.handle.net/11400/9865
dc.rights	Αναφορά Δημιουργού-Μη Εμπορική Χρήση-Όχι Παράγωγα Έργα 3.0 Ηνωμένες Πολιτείες	*
dc.rights.uri	http://creativecommons.org/licenses/by-nc-nd/3.0/us/	*
dc.source	http://scitation.aip.org/content/aapm/journal/medphys/33/12/10.1118/1.2372217	en
dc.subject	X-ray imaging
dc.subject	Phosphor screens
dc.subject	Απεικόνιση με ακτίνες Χ
dc.subject	Οθόνες φωσφόρου
dc.title	Modeling granular phosphor screens by Monte Carlo methods	en
heal.type	journalArticle
heal.classification	Science
heal.classification	Physics
heal.classification	Επιστήμες
heal.classification	Φυσική
heal.classificationURI	http://skos.um.es/unescothes/C03532
heal.classificationURI	http://skos.um.es/unescothes/C02994
heal.classificationURI	N/A-Επιστήμες
heal.classificationURI	N/A-Φυσική
heal.identifier.secondary	DOI: 10.1118/1.2372217
heal.language	en
heal.access	campus
heal.recordProvider	Τ.Ε.Ι. Αθήνας. Σχολή Τεχνολογικών Εφαρμογών. Τμήμα Μηχανικών Βιοϊατρικής Τεχνολογίας Τ.Ε.	el
heal.publicationDate	2006
heal.bibliographicCitation	Liaparinos, P., Kandarakis, I., Cavouras, D., Delis, H. and Panayiotakis, G. (2006). Modeling granular phosphor screens by Monte Carlo methods. Medical Physics. 33(12). pp. 4502-4514. American Association of Physicists in Medicine: 2006. Available from: http://scitation.aip.org/content/aapm/journal/medphys/33/12/10.1118/1.2372217 [Accessed 08/11/2006]	en
heal.abstract	The intrinsic phosphorproperties are of significant importance for the performance of phosphor screens used in medical imaging systems. In previous analytical-theoretical and Monte Carlo studies on granular phosphor materials, values of optical properties, and light interaction cross sections were found by fitting to experimental data. These values were then employed for the assessment of phosphor screen imaging performance. However, it was found that, depending on the experimental technique and fitting methodology, the optical parameters of a specific phosphor material varied within a wide range of values, i.e., variations of light scattering with respect to light absorption coefficients were often observed for the same phosphor material. In this study, x-ray and light transport within granular phosphor materials was studied by developing a computational model using Monte Carlo methods. The model was based on the intrinsic physical characteristics of the phosphor. Input values required to feed the model can be easily obtained from tabulated data. The complex refractive index was introduced and microscopic probabilities for light interactions were produced, using Mie scattering theory. Model validation was carried out by comparing model results on x-ray and light parameters (x-ray absorption, statistical fluctuations in the x-ray to light conversion process, number of emitted light photons, output light spatial distribution) with previous published experimental data on Gd2O2S:Tbphosphor material (Kodak Min-R screen). Results showed the dependence of the modulation transfer function(MTF) on phosphor grain size and material packing density. It was predicted that granular Gd2O2S:Tb screens of high packing density and small grain size may exhibit considerably better resolution and light emission properties than the conventional Gd2O2S:Tb screens, under similar conditions (x-ray incident energy, screen thickness).	en
heal.publisher	American Association of Physicists in Medicine	en
heal.journalName	Medical Physics	en
heal.journalType	peer-reviewed
heal.fullTextAvailability	true