1. Αποθετήριο Παραδοτέων Υποτρόφων Δράσεων ΕΣΠΑ Τριτοβάθμιας Εκπαίδευσης 2017-2023
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Τύπος:	Άρθρο σε επιστημονικό περιοδικό
Τίτλος:	Signal to Noise Ratio optimization for extended sources with a new kind of MURA masks
Συγγραφέας:	[EL] Καΐσας, Ιωάννης[EN] Kaissas, Ioannis [EL] Παπαδημητρόπουλος, Χρήστος[EN] Papadimitropoulos, Christos [EL] Κλούβας, Αλέξανδρος[EN] Clouvas, Alexandros [EL] Ποτηριάδης, Κωνσταντίνος[EN] Potiriadis, Constantinos [EL] Λαμπρόπουλος, Χαράλαμπος[EN] Lambropoulos, Charalambos
Ημερομηνία:	15/01/2020
Περίληψη:	Using coded aperture, for localization of radioactive hot-spots, results in enhanced efficiency and under certain configurations wide Field of View (FOV). We present a coded aperture assembly technique which can be restructured easily, as well as the reduction of the intrinsic noise of coded apertures constructed with this technique, when they localize spatially extended γ-emitters. Specifically, Modified-Uniformly-Redundant-Array (MURA) coded apertures are structured by embedding lead spheres in a matrix of positions machined inside a transparent medium such as acrylic glass, resulting in an advantageous transparent to opaque area ratio and thus an improved detection efficiency. This configuration also induces a systematic, element-wise, noise on the Point-Spread-Function (PSF) of the correlation matrix. When imaging with these apertures extended hot-spots, a penumbra phenomenon occurrs and reduces this intrinsic noise, in the way a kernel filter does. Fast-Fourier-Transform (FFT) is used to analyze the effect of this phenomenon on the correlation matrix and to explain the maximization of its Signal-to-Noise Ratio (SNR) for certain extent of the hot-spots. Simulations have been used for the detailed study of the SNR dependence on the dimensions of the hot-spot, while experiments with two 99mTc cylindrical sources with 11 mm and 24 mm diameter, respectively and 1.5 MBq activity each, confirm the reduction of the intrinsic noise. The results define the way of optimization of the imaging setup for the detection of extended hot-spots. Such an optimization could be useful for example in the case of lymph nodes or thyroid remnant imaging in nuclear medicine. Finally, we propose a kernel filter, derived by the Auto-Correlation-Function (ACF), to be applied on PSFs with high intrinsic noise, in order to eliminate it.
Γλώσσα:	Αγγλικά
Σελίδες:	7
DOI:	10.1088/1748-0221/15/01/C01012
ISSN:	1748-0221
Θεματική κατηγορία:	[EL] Πυρηνική φυσική[EN] Nuclear Physics [EL] Ραδιολογία, Πυρηνική ιατρική και Απεικονιστική[EN] Radiology, Nuclear Medicine and Imaging [EL] Πυρηνική ενέργεια και Μηχανική[EN] Nuclear Energy and Engineering
Λέξεις-κλειδιά:	Image filtering; Intra-operative probes; Medical-image reconstruction methods and algorithms; computer-aided software; Search for radioactive and fissile materials; Radiation
Κάτοχος πνευματικών δικαιωμάτων:	© 2020 IOP Publishing Ltd and Sissa Medialab
Ηλεκτρονική διεύθυνση του τεκμηρίου στον εκδότη:	https://iopscience.iop.org/article/10.1088/1748-0221/15/01/C01012
Ηλεκτρονική διεύθυνση περιοδικού:	https://iopscience.iop.org/journal/1748-0221
Τίτλος πηγής δημοσίευσης:	Journal of Instrumentation
Τεύχος:	1
Τόμος:	15
Σελίδες τεκμηρίου (στην πηγή):	Article no C01012
Όνομα εκδήλωσης:	21st International Workshop on Radiation Imaging Detectors
Τοποθεσία εκδήλωσης:	Crete, Greece
Ημ/νία έναρξης εκδήλωσης:	07/07/2019
Ημ/νία λήξης εκδήλωσης:	12/07/2019
Σημειώσεις:	This research is co-financed by Greece and the European Union (European Social Fund- ESF) through the Operational Programme «Human Resources Development, Education and Lifelong Learning 2014–2020» in the context of the project “Gamma Ray Tomographic Imaging for Medical and Industrial Applications”, (MIS5007234).
Εμφανίζεται στις συλλογές:	Ερευνητικές ομάδες