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Title: SU-E-I-49: Simulation Study for Removing Scatter Radiation in Cesium-Iodine Based Flat Panel Detector System

Purpose: This study aims to identify the feasibility of a novel cesium-iodine (CsI)-based flat-panel detector (FPD) for removing scatter radiation in diagnostic radiology. Methods: The indirect FPD comprises three layers: a substrate, scintillation, and thin-film-transistor (TFT) layer. The TFT layer has a matrix structure with pixels. There are ineffective dimensions on the TFT layer, such as the voltage and data lines; therefore, we devised a new FPD system having net-like lead in the substrate layer, matching the ineffective area, to block the scatter radiation so that only primary X-rays could reach the effective dimension.To evaluate the performance of this new FPD system, we conducted a Monte Carlo simulation using MCNPX 2.6.0 software. Scatter fractions (SFs) were acquired using no grid, a parallel grid (8:1 grid ratio), and the new system, and the performances were compared.Two systems having different thicknesses of lead in the substrate layer—10 and 20μm—were simulated. Additionally, we examined the effects of different pixel sizes (153×153 and 163×163μm) on the image quality, while keeping the effective area of pixels constant (143×143μm). Results: In case of 10μm lead, the SFs of the new system (∼11%) were lower than those of the other system (∼27% with no grid, ∼16% withmore » parallel grid) at 40kV. However, as the tube voltage increased, the SF of new system (∼19%) was higher than that of parallel grid (∼18%) at 120kV. In the case of 20μm lead, the SFs of the new system were lower than those of the other systems at all ranges of the tube voltage (40–120kV). Conclusion: The novel CsI-based FPD system for removing scatter radiation is feasible for improving the image contrast but must be optimized with respect to the lead thickness, considering the system’s purposes and the ranges of the tube voltage in diagnostic radiology. This study was supported by a grant(K1422651) from Institute of Health Science, Korea University.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4] ; ;  [5] ;  [6]
  1. Department of Health sciences, Graduate school of Medical sciences, Kyushu University, Fukuoka, JP (Japan)
  2. Radiation Safety & Section, Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of)
  3. Medical Radiation TF, Center for Disease Prevention, Korea Centers for Disease Control & Prevention, Cheongju, Chungchongbuk-do (Korea, Republic of)
  4. (Korea, Republic of)
  5. School of Health and Environmental Science, Korea University, Seoul (Korea, Republic of)
  6. Department of Health sciences, Faculty of Medical Sciences, Kyushu University, Fukuoka, JP (Japan)
Publication Date:
OSTI Identifier:
22494003
Resource Type:
Journal Article
Resource Relation:
Journal Name: Medical Physics; Journal Volume: 42; Journal Issue: 6; Other Information: (c) 2015 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 60 APPLIED LIFE SCIENCES; CESIUM; COMPUTER CODES; COMPUTERIZED SIMULATION; ELECTRIC POTENTIAL; IMAGES; IODINE; MONTE CARLO METHOD; PERFORMANCE; RADIOLOGY; THICKNESS; THIN FILMS