Experimental And Theoretical Evaluation Of A High Resolution Cmos Based Detector Under Xray Imaging Conditions

• doi: 10.1109/TNS.2010.2094206
• title: Experimental and Theoretical Evaluation of a High Resolution CMOS Based Detector Under X-Ray Imaging Conditions
• publisher: IEEE
• isbn:
• issn: 1558-1578
• rank: 2429
• access_type: LOCKED
• content_type: Journals
• 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 previously 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).
• article_number: 5676230
• pdf_url: https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=5676230
• html_url: https://ieeexplore.ieee.org/document/5676230/
• abstract_url: https://ieeexplore.ieee.org/document/5676230/
• publication_title: IEEE Transactions on Nuclear Science
• conference_location:
• conference_dates:
• publication_number: 23
• is_number: 5710484
• publication_year: 2011
• publication_date: Feb. 2011
• start_page: 314
• end_page: 322
• citing_paper_count: 55
• citing_patent_count: 1
• download_count: 954
• insert_date: 20101230
• index_terms:
  • ieee_terms:
    • Detectors
    • CMOS integrated circuits
    • Photonics
    • Pixel
    • X-ray imaging
    • Semiconductor device modeling
    • Phosphors
  • author_terms:
    • CMOS
    • digital mammography
    • digital radiography
    • image quality
  • dynamic_index_terms:
    • Imaging Conditions
    • Fourier Transform
    • Frequency Range
    • Image Quality
    • CCD Camera
    • Charge-coupled Device
    • X-ray Spectroscopy
    • X-ray Spectrometer
    • Image Sensor
    • Camera Sensor
    • Information Capacity
    • Modulation Transfer Function
    • Optical Transfer Function
    • Cadmium Telluride
    • Pixel Pitch
    • Radiation Quality
    • International Electrotechnical Commission
    • Noise Power Spectrum
    • Optical Photons
    • Layer Thickness
    • Fast Fourier Transform
    • Inverse Fast Fourier Transform
    • Slope Of Curve
    • X-ray Energy
    • Beam Quality
    • Shannon’s Information Theory
    • Shannon Theory
    • Range Of Spatial Frequencies
    • Surface Detection
    • Spatial Frequency Domain
    • Wide-sense Stationary
    • Covariance Stationary
    • Weak Stationarity
    • Phosphor Screen
    • Gain Factor
    • Mean Pixel Value
    • Dosimeter
• authors:
  • Author Name: Christos M. Michail
    Affiliation: Department of Medical Physics, Medical School, University of Patras, Patras, Greece
    Author URL: https://ieeexplore.ieee.org/author/37296357800
    ID: 37296357800
    Order: 1
    Author Affiliations:
    • Department of Medical Physics, Medical School, University of Patras, Patras, Greece
  • Author Name: Vasiliki A. Spyropoulou
    Affiliation: Department of Medical Physics, Medical School, University of Patras, Patras, Greece
    Author URL: https://ieeexplore.ieee.org/author/37064705600
    ID: 37064705600
    Order: 2
    Author Affiliations:
    • Department of Medical Physics, Medical School, University of Patras, Patras, Greece
  • Author Name: George P. Fountos
    Affiliation: Department of Medical Instruments Technology, Technological Education Institute of Athens, Athens, Greece
    Author URL: https://ieeexplore.ieee.org/author/37400620300
    ID: 37400620300
    Order: 3
    Author Affiliations:
    • Department of Medical Instruments Technology, Technological Education Institute of Athens, Athens, Greece
  • Author Name: Nektarios I. Kalyvas
    Affiliation: Department of Medical Instruments Technology, Technological Education Institute of Athens, Athens, Greece
    Author URL: https://ieeexplore.ieee.org/author/37541285400
    ID: 37541285400
    Order: 4
    Author Affiliations:
    • Department of Medical Instruments Technology, Technological Education Institute of Athens, Athens, Greece
  • Author Name: Ioannis G. Valais
    Affiliation: Department of Medical Instruments Technology, Technological Education Institute of Athens, Athens, Greece
    Author URL: https://ieeexplore.ieee.org/author/37296357000
    ID: 37296357000
    Order: 5
    Author Affiliations:
    • Department of Medical Instruments Technology, Technological Education Institute of Athens, Athens, Greece
  • Author Name: Ioannis S. Kandarakis
    Affiliation: Department of Medical Instruments Technology, Technological Education Institute of Athens, Athens, Greece
    Author URL: https://ieeexplore.ieee.org/author/37296048000
    ID: 37296048000
    Order: 6
    Author Affiliations:
    • Department of Medical Instruments Technology, Technological Education Institute of Athens, Athens, Greece
  • Author Name: George S. Panayiotakis
    Affiliation: Department of Medical Physics, Medical School, University of Patras, Patras, Greece
    Author URL: https://ieeexplore.ieee.org/author/37296297300
    ID: 37296297300
    Order: 7
    Author Affiliations:
    • Department of Medical Physics, Medical School, University of Patras, Patras, Greece

Image Sensor

• sensor_type: CMOS
• resolution: 1200x1600
• dynamic_range: superior compared to CCD
• pixel_size: 22.5 µm
• dark_current: low dark signal

Optical Data

• focal_length: not specified
• aperture: not specified
• field_of_view: not specified
• distortion: not specified

Performance Metrics

• signal_to_noise_ratio: high sensitivity performances
• power_consumption: lower power consumption compared to CCD, up to ten times lower for CMOS sensors
• noise: low read noise

Applications & Benefits

• cell_imaging: CMOS sensors used for imaging in medical applications, suitable for mammography
• benefits: High resolution, lower cost, reduced power consumption compared to CCDs, excellent linearity and sensitivity.

Supporting Organizations

• supported_by: Greek State Scholarships Foundation (I.K.Y.)

Manuscript Details

• publication_date: Feb. 2011

Relevancy Score

• score: 9
• missing_fields:
  • focal_length
  • aperture
  • field_of_view
  • distortion
  • frame_rate
  • sensitivity
  • shutter_speed

Processed JSON Filename

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