Experimental and theoretical evaluation of a high resolution CMOS based detector under X-ray imaging conditions

dc.contributor.author	Μιχαήλ, Χρήστος Μ.	el
dc.contributor.author	Σπυροπούλου, Βασιλική Α.	el
dc.contributor.author	Φούντος, Γεώργιος Π.	el
dc.contributor.author	Καλύβας, Νεκτάριος Ι.	el
dc.contributor.author	Βαλαής, Ιωάννης Γ.	el
dc.date.accessioned	2015-01-16T11:56:52Z
dc.date.issued	2015-01-16
dc.identifier.uri	http://hdl.handle.net/11400/4130
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.subject	X-ray imaging
dc.subject	Optical transfer function
dc.subject	Απεικόνισης με ακτίνες Χ
dc.subject	Οπτική συνάρτηση μεταφοράς
dc.title	Experimental and theoretical evaluation of a high resolution CMOS based detector under X-ray imaging conditions	en
heal.type	journalArticle
heal.classification	Medicine
heal.classification	Physics
heal.classification	Ιατρική
heal.classification	Φυσική
heal.classificationURI	http://id.loc.gov/authorities/subjects/sh00006614
heal.classificationURI	http://skos.um.es/unescothes/C02994
heal.classificationURI	N/A-Ιατρική
heal.classificationURI	N/A-Φυσική
heal.keywordURI	http://id.loc.gov/authorities/subjects/sh85095176
heal.contributorName	Student Member	en
heal.contributorName	IEEE	en
heal.contributorName	Κανδαράκης, Ιωάννης Σ.	el
heal.contributorName	Παναγιωτάκης, Γεώργιος Σ.	el
heal.identifier.secondary	DOI: 10.1109/TNS.2010.2094206
heal.dateAvailable	10000-01-01
heal.language	en
heal.access	forever
heal.recordProvider	Τ.Ε.Ι. Αθήνας. Σχολή Τεχνολογικών Εφαρμογών. Τμήμα Μηχανικών Βιοϊατρικής Τεχνολογίας Τ.Ε.	el
heal.publicationDate	2011
heal.bibliographicCitation	Michail, C., Spyropoulou, V., Fountos, G., Kalyvas, N., Valais, I., et al. (February 2011). Experimental and theoretical evaluation of a high resolution CMOS based detector under X-ray imaging conditions. Transactions on Nuclear Science. 58(1). pp. 314 - 322. IEEE.	en
heal.abstract	Fundamental imaging performance in terms of Modulation Transfer Function (MTF), Noise Power Spectrum (NPS) and Detective Quantum Efficiency (DQE) was investigated for a high resolution CMOS based imaging sensor. The device consists of a 33.91 mg/cm2 Gd2O2S:Tb scintillator screen, placed in direct contact with a CMOS photodiode array. The CMOS photodiode array, featuring 1200×1600 pixels with a pixel pitch of 22.5 μm, was used as an optical photon detector. In addition to the conventional frequency dependent parameters characterizing image quality, image information content was assessed through the application of information capacity (IC). The MTF was measured using the slanted-edge method to avoid aliasing while the Normalized NPS (NNPS) was determined by two-dimensional (2D) Fourier transforming of uniformly exposed images. Both measurements were performed under the representative radiation quality (RQA) settings, RQA-5 (70 kVp digital-radiography) and RQA-M2 (28 kVp digital-mammography) recommended by the International Electrotechnical Commission Reports 62220-1 and 62220-1-2 respectively. The DQE was assessed from the measured MTF, NPS and the direct entrance surface air-Kerma (ESAK) obtained from X-ray spectra measurement with a portable cadmium telluride (CdTe) detector. The ESAK values ranged between 11-87 μGy for RQA-5 and 6-40 μGy for RQA-M2. Additionally the output electrons per X-ray photon of the detector and its signal transfer characteristics were assessed via an analytical model, within the framework of the linear cascaded systems (LCS) theory. It was found that the detector response function was linear for the exposure ranges under investigation. Additionally our results showed that for the same RQA quality the output electrons per X-ray photon, as well as the measured and analytically predicted MTF, were not significantly affected by ESAK. MTF and DQE where found better compared to prev- - iously published data for other CCD and CMOS sensors, while the NNPS appeared to be comparable in the frequency range under investigation (0-10 cycles/mm).	en
heal.publisher	IEEE	en
heal.journalName	Transactions on Nuclear Science	en
heal.journalType	peer-reviewed
heal.fullTextAvailability	true