اندازه‌گیری پارامترهای کنترل کیفی آشکارساز تصویری Gd2O2S:Tb3+

نوع مقاله: مقاله پژوهشی

نویسندگان

1 گروه فیزیک، دانشکده علوم، دانشگاه آزاد اسلامی واحد تهران مرکزی، صندوق پستی: 1467686831، تهران ایران

2 پژوهشکده‌ی تحقیقات کشاورزی، پزشکی و صنعتی، پژوهشگاه علوم و فنون هسته‌ای، سازمان انرژی اتمی ایران، صندوق پستی: 498-31485، کرج ایران

3 گروه فیزیک، دانشکده علوم، دانشگاه آزاد اسلامی واحد تهران مرکزی، صندوق پستی: 1467686831، تهران ایران

چکیده

این مقاله مرحله­‌های مختلف طراحی، ساخت و بهینه­‌سازی مدل آزمایشی سیستم فلورسکپی صنعتی که بر پایه‌­ی آشکارساز سوسوزن Gd2O2S:Tb3+و با استفاده از تصویربرداری با لامپ پرتو ایکس kV200 و با جریان بیشینه­‌ی mA18 کار می­کند، را گزارش می‌­کند. به منظور بررسی عملکرد درست سیستم ساخته شده، تصویربرداری­ از مواد گوناگون، در ولتاژها و  فاصله­‌های مختلف انجام و کیفیت تصویر به دست آمده،  با استفاده از پارامترهای کنترل کیفیت کنتراست و توان تفکیک (FWHM) نمودارهای شدت روشنایی عنصرهای تصویر تعیین شد. نتایج حاصل از تحلیل تصویر، نشان­‌دهنده­‌ی این است که با ولتاژ مولد پرتو ایکس بین 80 تا 120 کیلو ولت و فاصله‌­ی بین منبع پرتو و آشکارساز  1.5متر، تصویر با بهترین کیفیت حاصل می‌­شود. در این شرایط بهترین کنتراست تصویر % 93.04 و توان تفکیک  4.03 عنصر تصویر (0.57 میلی­متر) است. لازم به ذکر است که پارامترهای کنتراست و توان تفکیک در ولتاژهای مختلف بسیار نزدیک به یک­دیگر است. بنابراین، این سیستم قابلیت استفاده درولتاژهای مختلف را دارا است.

تازه های تحقیق

  1. N. Soulfanidis, Translated by R. Koohi, M.H. HadiZade-Yazdi, Measurement and detection of radiation, Pub Simin (1991).

 2.   Curry Thomas, Dowdey James, Murry Robert, Translated by A. Takavar, M. Eftekhari, Christensen’s Physics of Diagnostic Radiology, Pub Aijh, 138 (2006).

  1. Steven J. Duclos, Scintillator Phosphors for Medical Imaging, The Electrochemical Society Interface, Summer (1998) 34-38.
  2. David J. Krus, Precision linear and two-dimensional scintillation crystal arrays for x- ray and gamma ray imaging applications, Presented at The SPIE International symposium on Optical Science, July (1999) 18-23.

 5.   M. Heydarian, Fundamental Physics of Radiology and Imaging Methods, Pub Qods Razavi (2001) 246.

 6.   I. Kandarakis, D. Cavouras, G. Panayiotakis, T. Agelis, C. Nomicosand GGiakoumakis, X-ray induced luminescence and spatial of La2O2S:Tb phosphor screens, Phys. Med. Biol, 41 (1996) 297-307.

 7.   I. Kandarakis, D. Cavouras, Experimental and theoretical assessment of the performance of Gd2O2S:Tb and La2O2S:Tb Phosphors and Gd2O2S:Tb-La2O2S:Tb mixtures for X-ray imaging, Eur. Radiol, 11 (2001) 1083-1091.

 8.   United States Patent, US 6, 676, 854 B2 (2004).

 9.   D. Cavouras, An experimental method to determine the effective luminescence efficiency of scintillator-photoetector combinations used in X-ray medical imaging systems, The British of Radiolgy, 71 (1998) 766-772.

 10.www.fa.wikipedia.org.

 11.www.xrayit.com/products.

 12.G.E. Giakoumakist, C.D. Nomicos, P.X. Sandilos, Absolute efficiency of Gd2O2S:Tb screens under fluoroscopic conditions, Phys. Med. Biol, 6 (1989) 673-678.

13.S. Chatterjee, Virendra Shanker, Harish Chander, Thermoluminescence of Tb doped Gd2O2S phosphor, Materials Chemistry and Physics, 80 (2003) 719-724.

 14.R. Morlotti, The Effect of Co-Doping by Ca+2, Ta+5, Sn+4 and Ru+4 Ions on the X-Ray Luminscent Properties of Gd2O2S:Tb+3 Phosphors, Jornal of the Electrochemical Society, 4 (2003) H81-H84.

 15.K.A. Wickersheim, R.V. Alves, R.A. Buchanan, Rareearthoxysulfide x-ray phosphors, IEEE Trans, Nucl. Sci. 17 (1970) 57–60.

 16.A.L.N. Stevels, A.D.M. Schrama-de Pauw, Vapour-deposited CsI:Na layers: I. Morphologic and crystallographic properties, Philips Res. Repts, 29 (1974) 340–352.

 17.A.L.N. Stevels, A.D.M. Schrama-de Pauw, Vapour-deposited CsI:Na layers: II. Screens for application inx-ray imaging devices, Philips Res. Repts, 29 (1974) 353–362.

18.INTERNATIONAL STANDARDS- ORGA NIZATION, X and Gamma Reference Radiation for Calibrating Dose Meters and Dose Rate Meters and for Determining Their Response as a Function Photon Energy-Characteristics of the Radiation and Their Methods of Production, ISO Standard (1996) 4037-1.

 19.http://www.nonius.com/KappaCCD/manuals/techinfo/techinfo.html.

 20.www.Samsungtechwin.com.

 21.www.samsungcctv.com.

 22.W.F.B. Vosslamber, H.H. Kiewiet, J.M. Schippers, X-ray imaging of rats by a scintillating screen and a CCD camera, File translated from TEX by TTH, version, 2.60 (2000).

 23.M. Tapiovaara, Objective Measurment of Image Quality in Fluoroscopic X-Ray Equipment, Radiation and Nuclear Safety Authority (2003) A196.

کلیدواژه‌ها


عنوان مقاله [English]

Measurement of Qualitative Control Parameters of Imaging Detector Gd2O2S:Tb3+

نویسندگان [English]

  • M Nazari 1
  • H Zamani Zeinali 2
  • N Abagheri Mahabadi 3
چکیده [English]

An imaging detector system based on scintillation detectors is designed, fabricated, and optimized for using in diagnostic radiology, industrial radiography, nuclear medicine, and research domain. The X ray from a Siemens Stabilipan Orthovoltage (SSO) unit after passing through an object, which may be a living sample or an electronic device, produces a planar distribution of visible light on a Gd2O2S:Tb3+(GOS), which is the image of the object under the examination. The image quality parameters, including the contrast and resolution were determined by the inpatient quality indicator (IQI) tests. The imaging practices were adopted for different X ray tube voltages (kV), and focal-spot surface distances (FSD). The data corresponding to the imaging quality parameters were subsequently analyzed and plotted by MATLAB and ORIGIN softwares. The results for the image quality parameters, that is, the contrast and resolution, for different X ray tube voltages were found to be fairly close to each other. Thus, the imaging system has the capability to be used for different X ray energies and radionuclides with relatively desired results. The study is considered to be an initiative for fabricating industrial fluoroscopy and radiation surveillance systems.

کلیدواژه‌ها [English]

  • Imaging Detector
  • Gd2O2S:Tb3+
  • Qualitative Control
  • Fluoroscopy
  1. N. Soulfanidis, Translated by R. Koohi, M.H. HadiZade-Yazdi, Measurement and detection of radiation, Pub Simin (1991).

 2.   Curry Thomas, Dowdey James, Murry Robert, Translated by A. Takavar, M. Eftekhari, Christensen’s Physics of Diagnostic Radiology, Pub Aijh, 138 (2006).

  1. Steven J. Duclos, Scintillator Phosphors for Medical Imaging, The Electrochemical Society Interface, Summer (1998) 34-38.
  2. David J. Krus, Precision linear and two-dimensional scintillation crystal arrays for x- ray and gamma ray imaging applications, Presented at The SPIE International symposium on Optical Science, July (1999) 18-23.

 5.   M. Heydarian, Fundamental Physics of Radiology and Imaging Methods, Pub Qods Razavi (2001) 246.

 6.   I. Kandarakis, D. Cavouras, G. Panayiotakis, T. Agelis, C. Nomicosand GGiakoumakis, X-ray induced luminescence and spatial of La2O2S:Tb phosphor screens, Phys. Med. Biol, 41 (1996) 297-307.

 7.   I. Kandarakis, D. Cavouras, Experimental and theoretical assessment of the performance of Gd2O2S:Tb and La2O2S:Tb Phosphors and Gd2O2S:Tb-La2O2S:Tb mixtures for X-ray imaging, Eur. Radiol, 11 (2001) 1083-1091.

 8.   United States Patent, US 6, 676, 854 B2 (2004).

 9.   D. Cavouras, An experimental method to determine the effective luminescence efficiency of scintillator-photoetector combinations used in X-ray medical imaging systems, The British of Radiolgy, 71 (1998) 766-772.

 10.www.fa.wikipedia.org.

 11.www.xrayit.com/products.

 12.G.E. Giakoumakist, C.D. Nomicos, P.X. Sandilos, Absolute efficiency of Gd2O2S:Tb screens under fluoroscopic conditions, Phys. Med. Biol, 6 (1989) 673-678.

13.S. Chatterjee, Virendra Shanker, Harish Chander, Thermoluminescence of Tb doped Gd2O2S phosphor, Materials Chemistry and Physics, 80 (2003) 719-724.

 14.R. Morlotti, The Effect of Co-Doping by Ca+2, Ta+5, Sn+4 and Ru+4 Ions on the X-Ray Luminscent Properties of Gd2O2S:Tb+3 Phosphors, Jornal of the Electrochemical Society, 4 (2003) H81-H84.

 15.K.A. Wickersheim, R.V. Alves, R.A. Buchanan, Rareearthoxysulfide x-ray phosphors, IEEE Trans, Nucl. Sci. 17 (1970) 57–60.

 16.A.L.N. Stevels, A.D.M. Schrama-de Pauw, Vapour-deposited CsI:Na layers: I. Morphologic and crystallographic properties, Philips Res. Repts, 29 (1974) 340–352.

 17.A.L.N. Stevels, A.D.M. Schrama-de Pauw, Vapour-deposited CsI:Na layers: II. Screens for application inx-ray imaging devices, Philips Res. Repts, 29 (1974) 353–362.

18.INTERNATIONAL STANDARDS- ORGA NIZATION, X and Gamma Reference Radiation for Calibrating Dose Meters and Dose Rate Meters and for Determining Their Response as a Function Photon Energy-Characteristics of the Radiation and Their Methods of Production, ISO Standard (1996) 4037-1.

 19.http://www.nonius.com/KappaCCD/manuals/techinfo/techinfo.html.

 20.www.Samsungtechwin.com.

 21.www.samsungcctv.com.

 22.W.F.B. Vosslamber, H.H. Kiewiet, J.M. Schippers, X-ray imaging of rats by a scintillating screen and a CCD camera, File translated from TEX by TTH, version, 2.60 (2000).

 23.M. Tapiovaara, Objective Measurment of Image Quality in Fluoroscopic X-Ray Equipment, Radiation and Nuclear Safety Authority (2003) A196.