International Journal of Precision Engineering and Manufacturing

Korean Society for Precision Engineering (한국정밀공학회)
권호 표지

On the Development of Digital Radiography Detectors: A Review

  • Kim, Ho-Kyung (School of Mechanical Engineering, Pusan National University) ;
  • Cunningham, Ian Alexander (Imaging Research Laboratories, Robarts Research institute) ;
  • Yin, Zhye (Computed Tomography System and Application Laboratory, GE Global Research Center) ;
  • Cho, Gyu-Seong (Department of Nuclear and Quantum Engineering, Korea Advanced Science and Technology)
  • Published : 2008.10.01
Download PDF
⟨ Previous Next ⟩

Abstract

This article reviews the development of flat-panel detectors for digital radiography based on amorphous materials, Important design parameters and developments are described for the two main components of flat-panel detectors: the X-ray converter and the readout pixel array. This article also introduces the advanced development concepts of new detectors. In addition, the cascaded linear systems method is reviewed because it is a very powerful tool for improving the design and assessment of X-ray imaging detector systems.

Keywords

References

  1. Weil, E., 'Some Bibliographical Notes on the First Publication on the Roentgen Rays,' Isis, Vol. 29, No. 2, pp. 362-365, 1938 https://doi.org/10.1086/347448
  2. Sonoda, M., Takano, M., Miyahara, J. and Kato, H., 'Computed Radiography Utilizing Scanning laser Stimulated Luminescence,' Radiology, Vol. 148, No. 3, pp. 833-838, 1983 https://doi.org/10.1148/radiology.148.3.6878707
  3. Rowlands, J. A., 'The Physics of Computed Radiography,' Phys. Med. Biol., Vol. 47, No. 23, pp. R123-R166, 2002 https://doi.org/10.1088/0031-9155/47/23/201
  4. Yaffe, M. J. and Rowlands, J. A., 'X-ray Detectors for Digital Radiography,' Phys. Med. Biol. Vol. 42, No. 1, pp. 1-39, 1997 https://doi.org/10.1088/0031-9155/42/1/001
  5. Street, R. A., Nelson, S., Antonuk, L. and Perez-Mendez, V., 'Amorphous Silicon Sensor Arrays for Radiation Imaging,' Proc. Mater. Res. Soc., Vol. 192, pp. 441-452, 1990
  6. Floyd, Jr., C. E., Warp, R. J., Dobbins, J. T. III, Chotas, H. G., Baydush, A. H., Vargas-Voracek, R. and Ravin, C. E., 'Imaging Characteristics of an Amorphous Silicon Flat-panel Detector for Digital Chest Radiography,' Radiology, Vol. 218, No. 3, pp. 683-688, 2001 https://doi.org/10.1148/radiology.218.3.r01fe45683
  7. Kotter, E. and Langer, M., 'Digital Radiography with Large-area Flat-panel Detectors,' Eur. Radiol., Vol. 12, No. 10, pp. 2562-2570, 2002 https://doi.org/10.1007/s00330-002-1350-1
  8. Zhao, W. and Rowlands, J. A., 'X-ray Imaging Using Amorphous Selenium: Feasibility of a Flat Panel Self-scanned Detector for Digital Radiology,' Med. Phys., Vol. 22, No. 10, pp. 1595-1604, 1995 https://doi.org/10.1118/1.597628
  9. Lee, D. L., Cheung, L. K. and Jeromin, L. S., 'A New Digital Detector for Projection Radiography,' Proc. SPIE, Vol. 2432, pp. 237-249, 1995
  10. Antonuk, L. E., Boudry, J., Huang, W., McShan, D. L., Morton, E. J., Yorkston, J., Longo, M. J. and Street, R. A., 'Demonstration of Megavoltage and Diagnostic X-ray Imaging with Hydrogenated Amorphous Silicon Arrays,' Med. Phys., Vol. 19, No. 6, pp. 1455-1466, 1992 https://doi.org/10.1118/1.596802
  11. James, J. J., Davies, A. G., Cowen, A. R. and O'Connor, P. J., 'Developments in Digital Radiography: An Equipment Update,' Eur. Radiol., Vol. 11, No. 12, pp. 2616-2626, 2001 https://doi.org/10.1007/s003300100828
  12. Spahn, M., 'Flat Detectors and Their Clinical Applications,' Eur. Radiol., Vol. 15, No. 9, pp. 1934-1947, 2005 https://doi.org/10.1007/s00330-005-2734-9
  13. Rowlands, J. and Kasap, S., 'Amorphous Semiconductors Usher in Digital X-ray Imaging,' Phys. Today, Vol. 50, No. 11, pp. 24-30, 1997
  14. Chotas, H. G., Dobbins, J. T. III and Ravin, C. E., 'Principles of Digital Radiography with Large-Area, Electronically Readable Detectors: a Review of the Basics,' Radiology, Vol. 210, No. 3, pp. 595-599, 1999 https://doi.org/10.1148/radiology.210.3.r99mr15595
  15. Rowlands, J. A. and Yorkston, J., 'Flat Panel Detectors for Digital Radiography,' Chapter 4, Handbook of Medical Imaging: Vol. 1. Physics and Psychophysics (Eds. Beutel, J., Kundel, H. L. and Van Metter, R.), SPIE, pp. 223-328, 2000
  16. Street, R. A., 'Large Area Image Sensor Arrays,' Chapter 4, Technology and Applications of Amorphous Silicon (Ed. R. A. Street), Springer-Verlag, pp. 147-221, 2000
  17. Moy, J.-P., 'Recent Developments in X-ray Imaging Detectors,' Nucl. Instrum. Meth. A, Vol. 442, No. 1-3, pp. 26-37, 2000 https://doi.org/10.1016/S0168-9002(99)01196-1
  18. Kasap, S. O. and Rowlands, J. A., 'Direct-conversion Flat-panel X-ray Image Detectors,' IEE Proc. -Circuits Devices Syst., Vol. 149, No. 2, pp. 85-96, 2002
  19. Antonuk, L. E., El-Mohri, Y., Jee, K.-W., Zhao, Q., Sawant, A., Su, Z. and Street, R. A., 'Technological Pathways for 21st Century Active Matrix X-ray Imager Development,' Proc. SPIE, Vol. 4682, pp. 1-8, 2002
  20. Yorkston, J., 'Recent Developments in Digital Radiography Detectors,' Nucl. Instrum. Meth. A, Vol. 580, No. 2, pp. 974-985, 2007 https://doi.org/10.1016/j.nima.2007.06.041
  21. Cunningham, I. A., Westmore, M. S. and Fenster, A., 'A Spatial-frequency Dependent Quantum Accounting Diagram and Detective Quantum Efficiency Model of Signal and Noise Propagation in Cascaded Imaging Systems,' Med. Phys., Vol. 21, No. 3, pp. 417-427, 1994 https://doi.org/10.1118/1.597401
  22. Cunningham, I. A. and Shaw, R., 'Signal-to-noise Optimization of Medical Imaging Systems,' J. Opt. Soc. Am. A, Vol. 16, No. 3, 621-632, 1999 https://doi.org/10.1364/JOSAA.16.000621
  23. Gagne, R. M., Quinn, P. W., Chen, L., Myers, K. J. and Doyle, R. J., 'Optically Coupled Digital Radiography: Sources of Inefficiency,' Proc. SPIE, Vol. 4320, pp. 156-162, 2001
  24. Kim, H. K., Cho, G., Lee, S. W., Shin, Y. H. and Cho, H. S., 'Development and Evaluation of a Digital Radiographic System Based on CMOS Image Sensor,' IEEE Trans. Nucl. Sci., Vol. 48, No. 3, pp. 662-666, 2001 https://doi.org/10.1109/23.940143
  25. Kim, H. K., Ahn, J. K. and Cho, G., 'Development of a Lens-coupled CMOS Detector for X-ray Inspection System,' Nucl. Instrum. Meth. A, Vol. 545, No. 1-2, pp. 210-216, 2005 https://doi.org/10.1016/j.nima.2005.01.310
  26. Cho, M. K., Kim, H. K. Graeve, T., Yun, S. M., Lim, C. H., Cho, H. and Kim, J.-M., 'Measurements of X-ray Imaging Performance of Granular Phosphors with Direct-coupled CMOS Sensors,' IEEE Trans. Nucl. Sci., Vol. 55, No. 3, pp. 1338-1343, 2008 https://doi.org/10.1109/TNS.2007.913939
  27. Bates, C. W., 'Scintillation Process in Thin Films of CsI(Na) and CsI(Tl) due to Low Energy X-rays, Electrons and Photons,' Adv. Electronics Electron Phys., Vol. 28A, pp. 451-459, 1968
  28. Stevels, A. L. N. and Schrama de Pauw, A. D. M., 'Vapor-deposited CsI:Na Layers, I. Morphologic and Crystallographic Properties, II. Screen for Application in X-ray Imaging Devices,' Philips Res. Rept., Vol. 29, pp. 340-362, 1974
  29. Ito, H., Matsubara, S., Takahashi, T., Shimada, T. and Takeuchi, H., 'Integrated Radiation Detectors with a-Si Photodiodes on Ceramic Scintillators,' Jpn. J. Appl. Phys., Vol. 28, No. 8, pp. L1476-L1479, 1989 https://doi.org/10.1143/JJAP.28.L1476
  30. Holl, I., Lorenz, E. and Mageras, G., 'A Measurement of Light Yield of Some Common Inorganic Scintillators,' IEEE Trans. Nucl. Sci., Vol. 35, No. 1, pp. 105-109, 1988 https://doi.org/10.1109/23.12684
  31. van Eijk, C. W. E., 'Inorganic Scintillators in Medical Imaging,' Phys. Med. Biol., Vol. 47, No. 8, pp. R85-R106, 2002 https://doi.org/10.1088/0031-9155/47/8/201
  32. Nikl, M., 'Scintillation Detectors for X-rays,' Meas. Sci. Technol., Vol. 17, No. 4, pp. R37-R54, 2006 https://doi.org/10.1088/0957-0233/17/4/R01
  33. Knoll, G. F., 'Radiation Detection and Measurement,' John Wiley & Sons, p. 49, 2000
  34. Klein, C. A., 'Bandgap Dependence and Related Features of Radiation Ionization Energies in Semiconductors,' J. Appl. Phys., Vol. 39, No. 4, pp. 2029-2038, 1968 https://doi.org/10.1063/1.1656484
  35. Que, W. and Rowlands, J. A., 'X-ray Photogeneration in Amorphous Selenium: Geminate versus Columnar Recombination,' Phys. Rev. B, Vol. 51, No. 16, pp. 10500-10507, 1995 https://doi.org/10.1103/PhysRevB.51.10500
  36. Kasap, S. O. and Rowlands, J. A., 'Photoconductor Selection for Digital Flat Panel X-ray Image Detectors Based on the Dark Current,' J. Vac. Sci. Technol. A, Vol. 18, No. 2, pp. 615-620, 2000 https://doi.org/10.1116/1.582237
  37. Hack, M., Guha, S. and Shur, M., 'Photoconductivity and Recombination in Amorphous Silicon Alloys,' Phys. Rev. B, Vol. 30, No. 12, pp. 6991-6999, 1984 https://doi.org/10.1103/PhysRevB.30.6991
  38. Guha, S. and Hack, M., 'Dominant Recombination Process in Amorphous Silicon Alloys,' J. Appl. Phys., Vol. 58, No. 4, pp. 1683-1685, 1985 https://doi.org/10.1063/1.336063
  39. Abkowitz, M., 'Density of States in a-Se from Combined Analysis of Xerographic Potentials and Transient Transport Data,' Phil. Mag. Lett., Vol. 58, No. 1, pp. 53-57, 1988 https://doi.org/10.1080/09500838808214730
  40. Haugen, C., Kasap, S. O. and Rowlands, J. A., 'X-ray Irradiation Induced Bulk Space Charge in Stabilized a-Se X-ray Photoconductors,' J. Appl. Phys., Vol. 84, No. 10, pp. 5495-5501, 1998 https://doi.org/10.1063/1.368859
  41. Zhao, W., DeCrescenzo, G. and Rowlands, J. A., 'Investigation of Lag and Ghosting in Amorphous Selenium Flat-Panel X-ray Detectors,' Proc. SPIE, Vol. 4682, pp. 9-20, 2002
  42. Zhao, B. and Zhao, W., 'Temporal Performance of Amorphous Selenium Mammography Detectors,' Med. Phys., Vol. 32, No. 1, pp. 128-136, 2005 https://doi.org/10.1118/1.1827791
  43. Zhao, W., DeCresenzo, G., Kasap, S. O. and Rowlands, J. A., 'Ghosting Caused by Bulk Charge Trapping in Direct Conversion Flat-panel Detectors Using Amorphous Selenium,' Med. Phys., Vol. 32, No. 2, pp. 488-500, 2005 https://doi.org/10.1118/1.1843353
  44. Rau, A. W., Bakueva, L. and Rowlands, J. A., 'The X-ray Time of Flight Method for Investigation of Ghosting in Amorphous Selenium-based Flat Panel Medical X-ray Imagers,' Med. Phys., Vol. 32, No. 10, pp. 3160-3177, 2005 https://doi.org/10.1118/1.2042248
  45. Siewerdsen, J. H. and Jaffray, D. A., 'A Ghost Story: Spatio-temporal Response Characteristics of an Indirect-detection Flat-panel Imager,' Med. Phys., Vol. 26, No. 8, pp. 1624-1641, 1999
  46. Kim, H. K., 'Analytical Model for Incomplete Signal Generation in Semiconductor Detectors,' Appl. Phys. Lett., Vol. 88, Issue 13, pp. 132112-1-132112-3, 2006 https://doi.org/10.1063/1.2191742
  47. Bloomquist, A. K., Yaffe, M. J., Mawdsley, G. E., Hunter, D. M. and Beideck, D. J., 'Lag and Ghosting in a Clinical Flat-panel Selenium Digital Mammography System,' Med. Phys., Vol. 33, No. 8, pp. 2998-3005, 2006 https://doi.org/10.1118/1.2218315
  48. Street, R. A., Ready, S. E, Melekhov, L., Ho, J., Zuck, A. and Breen, B., 'Approaching the Theoretical X-ray Sensitivity with HgI2 Direct Detection Image Sensors,' Proc. SPIE, Vol. 4682, pp. 414-422, 2002
  49. Street, R. A., 'Hydrogenated Amorphous Silicon,' Cambridge University Press, 1991
  50. Zhao, W., Belvis, I., Germann, S. and Rowlands, J. A., 'Digital Radiology Using Active Matrix Readout of Amorphous Selenium: Construction and Evaluation of a Prototype Real-time Detector,' Med. Phys., Vol. 24, No. 12, pp. 1834-1843, 1997 https://doi.org/10.1118/1.598098
  51. Zhao, W., Waechter, D. and Rowlands, J. A., 'Digital Radiology Using Active Matrix Readout of Amorphous Selenium: Radiation Hardness of Cadmium Selenide Thin Film Transistors,' Med. Phys., Vol. 25, No. 4, pp. 527-538, 1998 https://doi.org/10.1118/1.598233
  52. Zhao, W., Law, J., Waechter, D., Huang, Z. and Rowlands, J. A., 'Digital Radiology Using Active Matrix Readout of Amorphous Selenium: Detectors with High Voltage Protection,' Med. Phys., Vol. 25, No. 4, pp. 539-549, 1998 https://doi.org/10.1118/1.598229
  53. Pang, G., Zhao, W. and Rowlands, J. A., 'Digital Radiology Using Active Matrix Readout of Amorphous Selenium: Geometrical and Effective Fill Factors,' Med. Phys., Vol. 25, No. 9, pp. 1636-1646, 1998 https://doi.org/10.1118/1.598344
  54. Zhao, W. and Rowlands, J. A., 'Active Matrix X-ray Imaging Array,' United States Patent, No. 5,962,856, 1999
  55. Spear W. E. and LeComber P. G., 'Substitutional Doping of Amorphous Silicon,' Solid State Comm., Vol. 17, No. 9, pp. 1193-1196, 1975 https://doi.org/10.1016/0038-1098(75)90284-7
  56. Kim, H. J., Kim, H. K., Cho, G. and Choi, J., 'Construction and Characterization of An Amorphous Silicon Flat-panel Detector Based on Ion-shower Doping Process,' Nucl. Instrum. Meth. A, Vol. 505, No. 1-2, pp. 155-158, 2003 https://doi.org/10.1016/S0168-9002(03)01040-4
  57. Munro, P. and Bouius, D. C., 'X-ray Quantum Limited Portal Imaging Using Amorphous Silicon Flat-panel Arrays,' Med. Phys., Vol. 25, No. 5, pp. 689-702, 1998 https://doi.org/10.1118/1.598252
  58. Kameshima, T., Kaifu, N., Takami, E., Morishita, M. and Yamazaki, T., 'Novel Large Area MIS-type X-ray Image Sensor for Digital Radiography,' Proc. SPIE, Vol. 3336, pp. 453-462, 1998
  59. Weckler, G., 'Operation of p-n Junction Photodetectors in a Photon Flux Integrating Mode,' IEEE J. Solid-Sate Circuit, Vol. 2, No. 3, pp. 65-73, 1967 https://doi.org/10.1109/JSSC.1967.1049795
  60. Graeve, T., Huang, W., Alexander, S. M. and Li, Y., 'Amorphous Silicon Image Sensor for X-ray Applications,' Proc. SPIE, Vol. 2415, pp. 177-181, 1995
  61. Yarema, R. J., Zimmerman, T., Srage, J., Antonuk, L. E., Berry, J., Huang, W. and Maolinbay, M., 'A Programmable, Low Noise, Multichannel ASIC for Readout of Pixelated Amorphous Silicon Arrays,' Nucl. Instrum. Meth. A, Vol. 439, No. 2-3, pp. 413-417, 2000 https://doi.org/10.1016/S0168-9002(99)00900-6
  62. De Geronimo, G., O'Connor, P., Radeka, V. and Yu, B., 'Front-end Electronics for Imaging Detectors,' Nucl. Instrum. Meth. A, Vol. 471, No. 1-2, pp. 192-199, 2001 https://doi.org/10.1016/S0168-9002(01)00963-9
  63. Maolinbay, M., Zimmerman, T., Yarema, R. J., Antonuk, L. E., El-Mohri, Y. and Yeakey, M., 'Design and Performance of a Low Noise, 128-channel ASIC Preamplifier for Readout of Active Matrix Flat-panel Imaging Arrays,' Nucl. Instrum. Meth. A, Vol. 485, No. 1, pp. 661-675, 2002 https://doi.org/10.1016/S0168-9002(01)02129-5
  64. Huang, W., Antonuk, L. E., Berry, J., Maolinbay, M., Martelli, C., Mody, P., Nassif, S. and Yeakey, M., 'An Asynchronous, Pipelined, Electronic Acquisition System for Active Matrix Flat-panel Imagers (AMFPIs),' Nucl. Instrum. Meth. A, Vol. 431, No. 1-2, pp. 273-284, 1999 https://doi.org/10.1016/S0168-9002(99)00275-2
  65. Vedantham, S., Karellas, A., Suryanarayanan, S., Albagli, D., Han, S., Tkaczyk, E. J., Landberg, C. E., Opsahl-Ong, B., Granfors, P. R., Levis, I., D'Orsi, C. J. and Hendrick, R. E., 'Full Breast Digital Mammography with an Amorphous Silicon-based Flat Panel Detector: Physical Characteristics of a Clinical Prototype,' Med. Phys., Vol. 27, No. 3, pp. 558-567, 2000 https://doi.org/10.1118/1.598895
  66. Granfors, P. R. and Aufrichtig, R., 'Performance of a $41{\times}41-cm^2$ Amorphous Silicon Flat Panel X-ray Detector for Radiographic Imaging Applications,' Med. Phys., Vol. 27, No. 6, pp. 1324-1331, 2000 https://doi.org/10.1118/1.599010
  67. Granfors, P. R., Albagli, D. Tkaczyk, J. E., Aufrichtig, R., Netel, H., Brunst, G., Boudry, J. and Luo, D., 'Performance of a Flat Panel Cardiac Detector,' Proc. SPIE, Vol. 4320, pp. 77-84, 2001
  68. Yorker, J. G., Jeromin, L. S., Lee, D. L., Palecki, E. F., Golden, K. P. and Zhenxue, J., 'Characterization of a Full-field Digital Mammography Detector Based on Direct X-ray Conversion in Selenium,' Proc. SPIE, Vol. 4682, pp. 21-29, 2002
  69. Cheung, L. K., Jing, Z., Bogdanovich, S., Golden, K., Robinson, S., Beliaevskaia, E. and Parikh, S., 'Image Performance of a New Amorphous Selenium Flat Panel X-ray Detector Designed for Digital Breast Tomosynthesis,' Proc. SPIE, Vol. 5745, pp. 1282-1290, 2005
  70. Metz, C. E., Wagner, R. F., Doi, K., Brown, D. G., Nishikawa, R. M. and Myers, K. J., 'Toward Consensus on Quantitative Assessment of Medical Imaging Systems,' Med. Phys., Vol. 22, No. 7, pp. 1057-1061, 1995 https://doi.org/10.1118/1.597511
  71. Samei, E., Flynn, M. J., Chotas, H. G. and Dobbins, J. T., 'DQE of Direct and Indirect Digital Radiography System,' Proc. SPIE, Vol. 4320, pp. 189-197, 2001
  72. Shaw, J., Albagli, D., Wei, C. Y. and Granfors, P. R., 'Enhanced a-Si/CsI-based Flat panel X-ray Detector for Mammography,' Proc. SPIE, Vol. 5368, pp. 370-378, 2004
  73. Rivetti, S., Lanconelli, N., Campanini, R., Bertolini, M., Borasi, G., Nitrosi, A., Danielli, C., Angelini, L. and Maggi, S., 'Comparison of Different Commercial FFDM Units by Means of Physical Characterization and Contrast-detail Analysis,' Med. Phys., Vol. 33, No. 11, pp. 4198-4209, 2006 https://doi.org/10.1118/1.2358195
  74. Lazzari, B., Belli, G., Gori, G. and Rosselli Del Turco, M., 'Physical Characteristics of Five Clinical Systems for Digital Mammography,' Med. Phys., Vol. 34, No. 7, pp. 2730-2743 2007 https://doi.org/10.1118/1.2742498
  75. Monnin, P., Gutierrez, D., Bulling, S., Guntern, D. and Verdun, F. R., 'A Comparison of the Performance of Digital Mammography Systems,' Med. Phys., Vol. 34, No. 3, pp. 906-914, 2007 https://doi.org/10.1118/1.2432072
  76. Samei, E. and Flynn, M. J., 'An Experimental Comparison of Detector Performance for Direct and Indirect Digital Radiography Systems,' Med. Phys., Vol. 30, No. 4, pp. 608-622, 2003 https://doi.org/10.1118/1.1561285
  77. Borasi, G., Nitrosi, A., Ferrari, P. and Tassoni, D., 'On Site Evaluation of Three Flat Panel Detectors for Digital Radiography,' Med. Phys., Vol. 30, No. 7, pp. 1719-1731, 2003 https://doi.org/10.1118/1.1569273
  78. Borasi, G., Samei, E., Bertolini, M., Nitrosi, A. and Tassoni, D., 'Contrast-detail Analysis of Three Flat Panel Detectors for Digital Radiography,' Med. Phys., Vol. 33, No. 6, pp. 1707-1719, 2006 https://doi.org/10.1118/1.2191014
  79. Weisfield, R. L., Hartney, M., Schneider, R., Aflatooni, K. and Lujan, R., 'High Performance Amorphous Silicon Image Sensor for X-ray Diagnostic Medical Imaging Application,' Proc. SPIE, Vol. 3659, pp. 307-317, 1999
  80. Weisfield, R. L., Yao, W., Speaker, T., Zhou, K., Colbeth, R. and Proano, C., 'Performance Analysis of a 127-micron Pixel Large-area TFT/Photodiode Array with Boosted Fill Factor,' Proc. SPIE, Vol. 5368, pp. 338-348, 2004
  81. Ducourant, T., Michel, M. Vieux, G., Peppler, T., Trochet, J. C., Schulz, R. F., Bastiaens, R. J. M. and Busse, F., 'Optimization of Key Building Blocks for a Large-area Radiographic and Fluoroscopic Dynamic Digital X-ray Detector Based on a-Si:H/CsI:Tl Flat Panel Technology,' Proc. SPIE, Vol. 3977, pp. 14-25, 2000
  82. Ducourant, T., Couder, D., Wirth, T., Trochet, J. C., Bastiaens, R. J. M., Bruijins, T. J. C., Luijendijk, H. A., Sandkamp, B., Davies, A. G. and Didier, D., 'Image Quality of Digital Subtraction Angiography Using Flat Detector Technology,' Proc. SPIE, Vol. 5030, pp. 203-214, 2003
  83. Moy, J.-P., 'Signal-to-noise Ratio and Spatial Resolution in X-ray Electronic Imagers: Is the MTF a Relevant Parameter?' Med. Phys., Vol. 27, No. 1, pp. 86-93, 2000 https://doi.org/10.1118/1.598859
  84. Kleimann, P., Linnros, J., Frojdh, C. and Petersson, C. S., 'An X-ray Imaging Pixel Detector Based on Scintillator Filled Pores in a Silicon Matrix,' Nucl. Instrum. Meth. A, Vol. 460, No. 1, pp. 15-19, 2001 https://doi.org/10.1016/S0168-9002(00)01089-5
  85. Rocha, J. G. and Correia, J. H., 'A High-performance Scintillator-silicon-well X-ray Microdetector Based on DRIE Techniques,' Sensors and Actuators A, Vol. 92, No. 1-3, pp. 203-207, 2001 https://doi.org/10.1016/S0924-4247(01)00564-7
  86. Daniel, J. H., Krusor, B., Apte, R. B., Mulato, M., Van Schuylenbergh, K., Lau, R., Do, T., Street, R. A., Goredema, A. and Boils-Boissier, D. C., 'Micro-electro-mechanical System Fabrication Technology Applied to Large Area X-ray Image Sensor Arrays,' J. Vac. Sci. Technol. A, Vol. 19, No. 4, pp. 1219-1223, 2001 https://doi.org/10.1116/1.1380226
  87. Badel, X., Galeckas, A., Linnros, J., Kleimann, P., Frojdh, C. and Petersson, C. S., 'Improvement of an X-ray Imaging Detector Based on a Scintillating Guides Screen,' Nucl. Instrum. Meth. A, Vol. 487, No. 1-2, pp. 129-135, 2002 https://doi.org/10.1016/S0168-9002(02)00956-7
  88. Tao, S., Gu, Z. H. and Nathan, A., 'Fabrication of Gd2O2S:Tb Based Phosphor Films Coupled with Photodetectors for X-ray Imaging Applications,' J. Vac. Sci. Technol. A, Vol. 20, No. 3, pp. 1091-1094, 2002 https://doi.org/10.1116/1.1463082
  89. Rocha, J. G., Ramos, N. F., Lanceros-Mendez, S., Wolffenbuttel, R.. F. and Correia, J. H., 'CMOS X-rays Detector Array Based on Scintillating Light Guides,' Sensors and Actuators A, Vol. 110, No. 1-3, pp. 119-123, 2004 https://doi.org/10.1016/j.sna.2003.09.043
  90. Cha, B. K., Bae, J. H., Kim, B.-J., Jeon, H. and Cho, G., 'Performance Studies of a Monolithic Scintillator-CMOS Image Sensor for X-ray Application,' Nucl. Instrum. Meth. A, Vol. 591, No. 1, pp. 113-116, 2008 https://doi.org/10.1016/j.nima.2008.03.034
  91. Simon, M., Engel, K. J., Menser, B., Badel, X. and Linnros, J., 'X-ray Imaging Performance of Scintillator-filled Silicon Pore Arrays,' Med. Phys., Vol. 35, No. 3, pp. 968-981, 2008 https://doi.org/10.1118/1.2839441
  92. Kim, H. K., Yun, S. M., Ko, J. S., Cho, G. and Graeve, T., 'Cascade Modeling of Pixelated Scintillator Detectors for X-ray Imaging,' IEEE Trans. Nucl. Sci., Vol. 55, No. 3, pp. 1357-1366, 2008 https://doi.org/10.1109/TNS.2008.919260
  93. Antonuk, L. E., Jee, K.-W., El-Mohri, Y., Maolinbay, M., Nassif, S., Rong, X., Zhao, Q., Siewerdsen, J. H., Street, R. A. and Shah, K. S., 'Strategies to Improve the Signal and Noise Performance of Active Matrix, Flat-panel Imagers for Diagnostic X-ray Applications,' Med. Phys., Vol. 27, No. 2, pp. 289-306, 2000 https://doi.org/10.1118/1.598831
  94. El-Mohri, Y., Antonuk, L. E., Zhao, Q., Maolinbay, M., Rong, X., Jee, K.-W., Nassif, S. and Cionca, C., 'A Quantitative Investigation of Additive Noise Reduction for Active Matrix Flat-panel Imagers Using Compensation Lines,' Med. Phys., Vol. 27, No. 8, pp. 1855-1864, 2000 https://doi.org/10.1118/1.1287053
  95. Beuville, E., Belding, M., Costello, A., Hansen, R. and Petronio, S., 'High Performance, Low-noise, 128-channel Readout Integrated Circuit for Flat Panel X-ray Detector Systems,' Proc. SPIE, Vol. 5368, pp. 714-725, 2004
  96. Street, R. A., Ready, S. E., Van Schuylenbergh, K., Ho, J., Boyce, J. B. and Nylen, P., 'Comparison of $PbI_2$ and $HgI_2$ for Direct Detection Active Matrix X-ray Image Sensors,' J. Appl. Phys., Vol. 91, No. 5., pp. 3345-3355, 2002 https://doi.org/10.1063/1.1436298
  97. Kasap, S. O., Zahangir Kabir, M. and Rowlands, J. A., 'Recent Advances in X-ray Photoconductors for Direct Conversion X-ray Image Detectors,' Cur. Appl. Phys., Vol. 6, No. 3, pp. 288-292, 2006 https://doi.org/10.1016/j.cap.2005.11.001
  98. Schieber, M., Zuch, A., Gilboa, H. and Zentai, G., 'Reviewing Polycrystalline Mercuric Iodide X-ray Detectors,' IEEE Trans. Nucl. Sci., Vol. 53, No. 4, pp. 2385-2391, 2006 https://doi.org/10.1109/TNS.2006.877043
  99. Du, H., Antonuk, L. E., El-Mohri, Y., Zhao, Q., Su, Z., Yamamoto, J. and Wang, Y., 'Investigation of the Signal Behavior at Diagnostic Energies of Prototype, Direct Detection, Active Matrix, Flat-panel Imagers Incorporating Polycrystalline $HgI_2$,' Phys. Med. Biol., Vol. 53, No. 5, pp. 1325-1351, 2008 https://doi.org/10.1088/0031-9155/53/5/011
  100. Rahn, J. T., Lemmi, F., Weisfield, R. L., Lujan, R., Mei, P. Lu, J.-P., Ho, J., Ready, S. E., Apte, R. B., Nylen, P., Boyce, J. B. and Street, R. A., 'High Resolution, High Fill Factor a-Si:H Sensor Arrays for Medical Imaging,' Proc. SPIE, Vol. 3659, pp. 510-517, 1999
  101. Matsuura, N., Zhao, W., Huang, Z. and Rowlands, J. A., 'Digital Radiology Using Active Matrix Readout: Amplified Pixel Detector Array for Fluoroscopy,' Med. Phys., Vol. 26, No. 5, pp. 672-681, 1999 https://doi.org/10.1118/1.598572
  102. Karim, K. S., Nathan, A. and Rowlands, J. A., 'Alternative Pixel Architectures for Large Area Medical Imaging,' Proc. SPIE, Vol. 4320, pp. 35-46, 2001
  103. Lu, J. P., Van Schuylenbergh, K., Ho, J., Wang, Y., Boyce, J. B. and Street, R. A., 'Flat Panel Imagers with Pixel Level Amplifiers Based on Polycrystalline Silicon Thin-film Transistor Technology,' Appl. Phys. Lett., Vol. 80, No. 24, pp. 4656-4658, 2002 https://doi.org/10.1063/1.1481788
  104. Antonuk, L. E., Li, Y., Du, H., El-Mohri, Y., Zhao, Q., Yamamoto, J., Sawant, A., Wang, Y., Su, Z., Lu, J.-P., Street, R. A., Weisfield, R. and Yao, B., 'Investigation of Strategies to Achieve Optimal DQE Performance from Indirect Detection Active Matrix Flat-panel Imagers (AMFPIs) through Novel Pixel Amplification Architectures,' Proc. SPIE, Vol. 5745, pp. 18-31, 2005
  105. Antonuk, L. E., El-Mohri, Y., Zhao, Q., Koniczek, M., McDonald, J., Yeakey, M., Wang, Y., Behravan, M., Street, R. A. and Lu, J.-P., 'Exploration of the Potential Performance of Polycrystalline Silicon-based Active Matrix Flat-panel Imagers Incorporating Active Pixel Sensor Architectures,' Proc. SPIE, Vol. 6913, pp. 69130I-1-69130I-13, 2005
  106. Zhao, W., Hunt, D. C., Tanioka, K. and Rowlands, J. A., 'Indirect Flat-panel Detector with Avalanche Gain,' Proc. SPIE, Vol. 5368, pp. 150-161, 2004
  107. Zhao, W., Hunt, D. C., Tanioka, K. and Rowlands, J. A., 'Amorphous Selenium Flat Panel Detectors for Medical Applications,' Nucl. Instrum. Meth. A, Vol. 549, No. 1-3, pp. 205-209, 2005 https://doi.org/10.1016/j.nima.2005.04.053
  108. Zhao, W., Li, D., Rowlands, J. A., Egami, N., Takiguchi, Y., Nanba, M., Honda, Y., Ohkawa, Y., Kubota, M., Tanioka, K., Suzuki, K. and Kawai, T., 'An Indirect Flat-panel Detector with Avalanche Gain for Low Dose X-ray Imaging: SAPHIRE (Scintillator Avalanche Photoconductor with High Resolution Emitter Readout),' Proc. SPIE, Vol. 6913, pp. 69130M-1-69130M-11, 2008
  109. Li, D. and Zhao, W., 'SAPHIRE (Scintillator Avalanche Photoconductor with High Resolution Emitter Readout) for Low Dose X-ray Imaging: Spatial Resolution,' Med. Phys. Vol. 35, No. 7, pp. 3151-3161, 2008 https://doi.org/10.1118/1.2937652
  110. Zhao, W., Li, D., Reznik, A., Lui, B., Hunt, D. C., Tanioka, K. and Rowlands, J. A., 'Indirect Flat-panel Detector with Avalanche Gain: Fundamental Feasibility Investigation for SHARP-AMFPI (Scintillator HARP Active Matrix Flat Panel Imager),' Med. Phys. Vol. 32, No. 9, pp. 2954-2966, 2005 https://doi.org/10.1118/1.2008428
  111. Dimitrakopoulos, C. D. and Malenfant, R. L., 'Organic Thin Film Transistors for Large Area Electronics,' Adv. Mater., Vol. 14, No. 2, pp. 99-117, 2002 https://doi.org/10.1002/1521-4095(20020116)14:2<99::AID-ADMA99>3.0.CO;2-9
  112. Wong, W. S., Ready, S., Matusiak, R., White, S. D., Lu, J.-P., Ho, J. and Street, R. A., 'Amorphous Silicon Thin-film Transistors and Arrays Fabricated by Jet Printing,' Appl. Phys. Lett., Vol. 80, No. 4, pp. 610-612, 2002 https://doi.org/10.1063/1.1436273
  113. Paul, K. E., Wong, W. S., Ready, S. E. and Street, R. A., 'Additive Jet Printing of Polymer Thin-film Transistors,' Appl. Phys. Lett., Vol. 83, No. 10, pp. 2070-2072, 2003 https://doi.org/10.1063/1.1609233
  114. Arias, A. C., Ready, S. E., Lujan, R., Wong, W. S., Paul, K. E., Salleo, A., Chabinyc, M. L., Apte, R., Street, R. A., Wu, Y., Liu, P. and Ong, B., 'All Jet-Printed Polymer Thin-film Transistor Active-matrix Backplanes,' Appl. Phys. Lett., Vol. 85, No. 15, pp. 3304-3306, 2004 https://doi.org/10.1063/1.1801673
  115. Street, R. A., Wong, W. S., Ready, S., Lujan, R., Arias, A. C., Chabinyc, M. L., Salleo, A., Apte, R. and Antonuk, L. E., 'Printed Active-Matrix TFT Arrays for X-ray Imaging,' Proc. SPIE, Vol. 5745, pp. 7-17, 2005
  116. Ng, T. N., Lujan, R. A., Sambandan, S., Street, R. A., Limb, S. and Wong, W. S., 'Low Temperature a-Si:H Photodiodes and Flexible Image Sensor Arrays Patterned by Digital Lithography,' Appl. Phys. Lett., Vol. 91, No. 6, pp. 063505-1-063505-3, 2007 https://doi.org/10.1063/1.2767981
  117. Swank, R. K., 'Absorption and Noise in X-ray Phosphors,' J. Appl. Phys., Vol. 44, No. 9, pp. 4199-4203, 1973 https://doi.org/10.1063/1.1662918
  118. Francke, T., Eklund, M., Ericsson, L, Kristoffersson, T., Peskov, V. N., Rantanen, J., Sokolov, S., Soderman, J. E., Ullberg, C. K. and Weber, N., 'Dose Reduction Using Photon Counting X-ray Imaging,' Proc. SPIE, Vol. 4320, pp. 127-132, 2001
  119. Llopart, X., Campbell, M., Dinapoli, R., San Segundo, D. and Pernigotti, E., 'Medipix2: a 64-k Pixel Readout Chip with $55 {\mu}m$ Square Elements Working in Single Photon Counting Mode,' IEEE Trans. Nucl. Sci., Vol. 49, No. 5, pp. 2279-2283, 2002 https://doi.org/10.1109/TNS.2002.803788
  120. Sauli, F., 'GEM: a New Concept for Electron Amplification in Gas Detectors,' Nucl. Instrum. Meth. A, Vol. 386, No. 2-3, pp. 531-534, 1997 https://doi.org/10.1016/S0168-9002(96)01172-2
  121. Giomataris, Y., Rebourgeard, Ph., Robert, J. P. and Charpak, G., 'MICROMEGAS: a High-granularity Position-sensitive Gaseous Detectors for High Particle-flux Environments,' Nucl. Instrum. Meth. A, Vol. 376, No. 1, pp. 29-35, 1996 https://doi.org/10.1016/0168-9002(96)00175-1
  122. Mettivier, G., Montesi, M. C. and Russo, P., 'First Images of a Digital Autoradiography System Based on a Medipix2 Hybrid Silicon Pixel Detector,' Phys. Med. Biol., Vol. 48, No. 12, pp. N173-N181, 2003 https://doi.org/10.1088/0031-9155/48/12/403
  123. Avila, C., Lopez, J., Sanabria, J. C., Baldazzi, G., Bollini, D., Gombia, M., Cabal, A. E., Ceballos, C., Diz Garcia, A., Gambaccini, M., Taibi, A., Sarnelli, A., Tuffanelli, A., Giubellino, P., Marzari-Chiesa, A., Prino, F., Tomassi, E., Grybos, P., Idzik, M., Swientek, K., Wiacek, P., Montano, L. M., Ramello, L. and Sitta, M., 'Contrast Cancellation Technique Applied to Digital X-ray Imaging Using Silicon Strip Detectors,' Med. Phys., Vol. 32, No. 12, pp. 3755-3766, 2005 https://doi.org/10.1118/1.2126568
  124. Gobbi, D. G., Dixit, M. S., Dubeau, J. and Johns, P. C., 'Photon-counting Radiography with the Gas Microstrip Detector,' Phys. Med. Biol., Vol., 44, No. 5, pp. 1317-1335, 1999 https://doi.org/10.1088/0031-9155/44/5/317
  125. Shikhaliev, P. M., Xu, T. and Molloi, S., 'Photon Counting Computed Tomography: Concept and Initial Results,' Med. Phys., Vol. 32, No. 2, pp. 427-436, 2005 https://doi.org/10.1118/1.1854779
  126. Davidson, D. W., Watt, J., Tlustos, L., Mikulec, B., Campbell, M., Mathieson, K., O'Shea, V., Smith, K. M. and Rahman, M., 'Detective Quantum Efficiency of the Medipix Pixel Detector,' IEEE Trans. Nucl. Sci., Vol. 50, No. 5, pp. 1659-1663, 2003 https://doi.org/10.1109/TNS.2003.817382
  127. Annovazzi, A., Amendolia, S. R., Bigongiari, A., Bisogni, M. G., Catarsi, F., Cesqui, F., Cetronio, A., Colombo, F., Delogu, P., Fantacci, M. E., Gilberti, A., Lanzieri, C., Lavagna, S., Novelli, M., Passuello, G., Paternoster, G., Pieracci, M., Poletti, M., Quattrocchi, M., Rosso, V., Stefanini, A., Testa, A. and Venturelli, L., 'A GaAs Pixel Detectors-based Digital Mammographic System: Performances and Imaging Tests Results,' Nucl. Instrum. Meth. A, Vol. 576, No. 1, pp. 154-159, 2007 https://doi.org/10.1016/j.nima.2007.01.144
  128. Bertolucci, E., Maiorino, M., Mettivier, G., Montesi, M. C. and Russo, P., 'Preliminary Test of an Imaging Probe for Nuclear Medicine Using Hybrid Pixel Detectors,' Nucl. Instrum. Meth. A, Vol. 487, No. 1-2, pp. 193-201, 2002 https://doi.org/10.1016/S0168-9002(02)00965-8
  129. Frojdh, C., Graafsma, H., Nilsson, H. E. and Ponchut, C., 'Characterization of a Pixellated CdTe Detector with Single-photon Processing Readout,' Nucl. Instrum. Meth. A, Vol. 563, No. 1, pp. 128-132, 2006 https://doi.org/10.1016/j.nima.2006.01.076
  130. Mettivier, G., Montesi, M. C. and Russo, P., 'Digital Autoradiography with a Medipix2 Hybrid Silicon Pixel Detector,' IEEE Trans. Nucl. Sci., Vol. 52, No. 1, pp. 46-50, 2005 https://doi.org/10.1109/TNS.2004.843122
  131. Thunberg, S., Francke, T., Egerstrom, J., Eklund, M., Ericsson, L., Kristoffersson, T., Peskov, V., Rantanen, J., Sokolov, S., Svedenhag, P., Ullberg, C. K. and Weber, N., 'Evaluation of a Photon Counting Mammography System,' Proc. SPIE, Vol. 4682, pp. 202-208, 2002
  132. Thunberg, S., Adelow, L., Blom, O., Coster, A., Egerstrom, J., Eklund, M., Egnell, P., Francke, T., Jordung, U., Kristoffersson, T., Lindman, K., Lindqvist, L., Marchal, D., Olla, H., Penton, E., Peskov, V., Rantanen, J., Sokolov, S., Svedenhag, P., Ullberg, C. and Weber, N., 'Dose Reduction in Mammography with Photon Counting Imaging,' Proc. SPIE, Vol. 5368, pp. 457-465, 2004
  133. Maidment, A., Albert, M., Thunberg, S., Adelow, L, Blom, O., Egerstrom, J., Eklund, M., Francke, T., Jordung, U., Kristoffersson, T., Lindman, K., Lindqvist, L, Marchal, D., Olla, H., Penton, E., Rantanen, J., Solokov, S., Ullberg, C. and Weber, N., 'Evaluation of a Photon-counting Breast Tomosynthesis Imaging System,' Proc. SPIE, Vol. 5745, pp. 572-582, 2005
  134. Mikulec, B., 'Development of Segmented Semiconductor Arrays for Quantum Imaging,' Nucl. Instrum. Meth. A, Vol. 510, No. 1-2, pp. 1-23, 2003 https://doi.org/10.1016/S0168-9002(03)01672-3
  135. Rossmann, K., 'Measurement of the Modulation Transfer Function of Radiographic Systems Containing Fluorescent Screens,' Phys. Med. Biol., Vol. 9, No. 4, pp. 551-557, 1964 https://doi.org/10.1088/0031-9155/9/4/312
  136. Rossmann, K., 'The Spatial Frequency Spectrum: a Means for Studying the Quality of Radiographic Imaging Systems,' Radiology, Vol. 90, No. 1, pp. 1-13, 1968 https://doi.org/10.1148/90.1.1
  137. Rossmann, K., 'Point Spread-function, Line Spread-function, and Modulation Transfer Function. Tools for the Study of Imaging Systems,' Radiology, Vol. 93, No. 2, pp. 257-272, 1969 https://doi.org/10.1148/93.2.257
  138. Barrett, H. H. and Swindell, W., 'Radiological Imaging - the Theory of Image Foundation, Detection, and Processing,' Academic Press, 1981
  139. Papoulis, A., 'Probability, Random Variables, and Stochastic Processes,' McGraw-Hill, 1991
  140. Jenkins, G. M. and Watts, D. G., 'Spectral Analysis and Its Application,' Holden-Day Series in Time Series Analysis, Holden-Day, 1968
  141. Giger, M. L., Doi, K. and Metz, C. E., 'Investigation of Basic Imaging Properties in Digital Radiography. 2. Noise Wiener Spectrum,' Med. Phys., Vol. 11, No. 6, pp. 797-805, 1984 https://doi.org/10.1118/1.595583
  142. Shaw, R., 'The Equivalent Quantum Efficiency of the Photographic Process,' J. Photogr. Sc., Vol. 11, pp. 199-204, 1963 https://doi.org/10.1080/00223638.1963.11736919
  143. Wagner, R. F. and Brown, D. G., 'Unified SNR Analysis of Medical Imaging Systems,' Phys. Med. Biol., Vol. 30, No. 6, pp. 489-518, 1985 https://doi.org/10.1088/0031-9155/30/6/001
  144. ICRU 54, 'Medical Imaging - the Assessment of Image Quality,' International Commission of Radiation Units and Measurements, 1995
  145. Cunningham, I. A., 'Applied Linear-systems Theory,' Chapter 2, Handbook of Medical Imaging: Vol. 1. Physics and Psychophysics (Eds. Beutel, J., Kundel, H. L. and Van Metter, R.), SPIE, pp. 79-159, 2000
  146. Barrett, H. H. and Meyers, K. J., 'Foundations of Image Science,' Wiley, 2004
  147. Papoulis, A., 'Systems and Transforms with Applications in Optics,' McGraw-Hill, 1968
  148. Dainty, J. C. and Shaw, R., 'Image Science,' Academic Press, 1974
  149. Gaskill, J. D., 'Linear Systems, Fourier Transforms, and Optics,' John Wiley & Sons, 1978
  150. Doi, K., 'Field Characteristics of Geometric Unsharpness Due to the X-ray Tube Focal Spot,' Med. Phys., Vol. 4, No. 1, pp. 15-20, 1977 https://doi.org/10.1118/1.594378
  151. Metz, C. E. and Doi, K., 'Transfer Function Analysis of Radiographic Imaging Systems,' Phys. Med. Biol., Vol. 24, No. 6, pp. 1079-1106, 1979 https://doi.org/10.1088/0031-9155/24/6/001
  152. Rabbani, M. Shaw, R. and van Metter, R. L., 'Detective Quantum Efficiency of Imaging Systems with Amplifying and Scattering Mechanisms,' J. Opt. Soc. Am. A, Vol. 4, No. 5, pp. 895-901, 1987 https://doi.org/10.1364/JOSAA.4.000895
  153. Rabbani, M. and van Metter, R. L., 'Analysis of Signal and Noise Propagation for Several Imaging Mechanisms,' J. Opt. Soc. Am. A, Vol. 6, No. 8, pp. 1156-1164, 1989 https://doi.org/10.1364/JOSAA.6.001156
  154. Sattarivand, M. and Cunningham, I. A., 'Computational Engine for Development of Complex Cascaded Models of Signal and Noise in X-ray Imaging Systems,' IEEE Trans. Med. Imag., Vol. 24, No. 2, pp. 211-222, 2005 https://doi.org/10.1109/TMI.2004.839680
  155. Zhao, W. and Rowlands, J. A., 'Digital Radiology Using Active Matrix Readout of Amorphous Selenium: Theoretical Analysis of Detective Quantum Efficiency,' Med. Phys., Vol. 24, No. 12, pp. 1819-1833, 1997 https://doi.org/10.1118/1.598097
  156. Siewerdsen, J. H., Antonuk, L. E., El-Mohri, Y., Yorkston, J., Huang, W., Boudry, J. M. and Cunningham, I. A., 'Empirical and Theoretical Investigation of the Noise Performance of Indirect Detection, Active Matrix Flat-panel Imagers (AMFPIs) for Diagnostic Radiology,' Med. Phys., Vol. 24, No. 1, pp. 71-89, 1997 https://doi.org/10.1118/1.597919
  157. Siewerdsen, J. H., Antonuk, L. E., El-Mohri, Y., Yorkston, J., Huang, W. and Cunningham, I. A., 'Signal, Noise Power Spectrum and Detective Quantum Efficiency of Indirect-detection Flat-panel Imagers for Diagnostic Radiology,' Med. Phys., Vol. 25, No. 5, pp. 614-628, 1998 https://doi.org/10.1118/1.598243
  158. Zhao, W., Ji, W. G. and Rowlands, J. A., 'Effects of Characteristic X rays on the Noise Power Spectra and Detective Quantum Efficiency of Photoconductive X-ray Detectors,' Med. Phys., Vol. 28, No. 10, pp. 2039-2049, 2001 https://doi.org/10.1118/1.1405845
  159. Cunningham, I. A. and Yao, J., 'Cascaded Models and the DQE of Flat-panel Imagers: Noise Aliasing, Secondary Quantum Noise and Reabsorption,' Proc. SPIE, Vol. 4682, pp. 61-72, 2002
  160. Richard, S., Siewerdsen, J. H., Jaffray, D. A., Moseley, D. J. and Bakhtiar, B., 'Generalized DQE Analysis of Radiographic and Dual-energy Imaging Using Flat-panel Detectors,' Med. Phys., Vol. 32, No. 5, pp. 1397-1413, 2005 https://doi.org/10.1118/1.1901203
  161. Hajdok, G., Yao, J., Battista, J. J. and Cunningham, I. A., 'Signal and Noise Transfer Properties of Photoelectric Interactions in Diagnostic X-ray Imaging Detectors,' Med. Phys., Vol. 33, No. 10, pp. 3601-3620, 2006 https://doi.org/10.1118/1.2336507
  162. El-Mohri, Y., Antonuk, L. E., Zhao, Q., Wang, Y., Li, Y., Du, H. and Sawant, A., 'Performance of a High Fill Factor, Indirect Detection Prototype Flat-panel Imager for Mammography,' Med. Phys., Vol. 34, No. 1, pp. 315-327, 2007 https://doi.org/10.1118/1.2403967
  163. Hunt, D. C., Tanioka, K. and Rowlands, J. A., 'X-ray Imaging Using Avalanche Multiplication in Amorphous Selenium: Investigation of Depth Dependent Avalanche Noise,' Med. Phys., Vol. 34, No. 3, pp. 976-986, 2007 https://doi.org/10.1118/1.2437097
  164. Richard, S. and Siewerdsen, J. H., 'Optimization of Dual-energy Imaging Systems Using Generalized NEQ and Imaging Task,' Med. Phys., Vol. 34, No. 1, pp. 127-139, 2007 https://doi.org/10.1118/1.2400620
  165. Yao, J. and Cunningham, I. A., 'Parallel Cascades: New Ways to Describe Noise Transfer in Medical Imaging Systems,' Med. Phys., Vol. 28, No. 10, pp. 2020-2038, 2001 https://doi.org/10.1118/1.1405842
  166. Akbarpour, R., Friedman, S. N., Siewerdsen, J. H., Neary, J. D. and Cunningham, I. A., 'Signal and Noise Transfer in Spatiotemporal Quantum-based Imaging Systems,' J. Opt. Soc. Am. A, Vol. 24, No. 12, pp. B151-B164, 2007 https://doi.org/10.1364/JOSAA.24.00B151
  167. Kim, H. K., 'Generalized Cascaded Model to Assess Noise Transfer in Scintillator-based X-ray Imaging Detectors,' Appl. Phys. Lett., Vol. 89, Issue 23, pp. 233504-1-233504-3, 2006 https://doi.org/10.1063/1.2398926