Dijital radyografi sistemlerinde gürültünün konum ve frekans uzayında irdelenmesi

Dijital radyografi görüntüsündeki gürültü miktarı, düşük kontrasttaki lezyonların saptanmasına önemli ölçüde sınırlama getirir. Bu çalışmanın amacı bir dijital radyografi görüntüsünde, gürültü bileşenlerinin hem konum hem de frekans uzayında saptanmasıdır. Konum uzayında gürültü analizi bağıl gürültü varyansı analiz yöntemi ile, frekans uzayında gürültü analizi ise normalize gürültü güç spektrumunun ölçülmesi aracılığıyla gerçekleştirilmiştir.

Investigation of the noise in spatial and frequency domain for digital radiography systems

Noise amount in digital radiographic image puts a limitation on detection of low contrast lesions. The aim of this study is to investigate of the noise component in digital radiographic image in both spatial and frequency domain. Noise analysis in spatial and frequency domain was performed by using relative noise variance and noise power spectra measurement methods, respectively.

PDF

___

M. J. Yaffe and J A Rowlands, “X-ray detectors for digital radiography,” Phys. Med. Biol., Vol.42, pp. 1–39, 1997.
E. Samei, “Performance of digital radiographic detectors: quantification and assessment methods”, In: Samei E, Flynn MJ, editors. “Syllabus: advances in digital radiography-categorical course in diagnostic radiology physics,” Oak Brook, IL: Radiological Society of North America. pp. 37-47, 2003.
M.B. Williams, P.A. Mangiafico, P.U. Simoni, “Noise power spectra of images from digital mammography detectors,” Med Phys, vol. 26, no. 7, pp. 1279-1293, 1999.
J.T. Bushberg, J.A. Seibert, E.M. Leidholdt, J.M. Boone, “The Essential Physics of Medical Imaging. 2nd ed.,” Philadelphia, Pa: Lippincott Williams & Wilkins, 2001. ISBN: 0-683-30118-7.
N.W. Marshall, P. Monnin, H. Bosmans, F.O. Bochud, F.R. Verdun, “Image quality assessment in digital mammography: part I. Technical characterization of the systems,” Phys Med Biol, vol. 56, no. 14, pp. 4201- 4220, 2011.
V. Ravaglia, R. Bouwman, K. Young, R. Van Engen and B. Lazzari, “Noise analysis of full field digital mammography systems,” Proc. of SPIE, vol. 7258 : 72581B, pp 1-11, 2009.
A. Burgess, “On the noise variance of a digital mammography system,” Med Phys, vol. 31, no. 7, pp. 1987-1995, 2004.
S. Rivetti, N. Lanconelli, R. Campanini, M. Bertolini, G. Borasi, A. Nitrosi, C. Danielli, L. Angelini, S. Maggi, “Comparison of different commercial FFDM units by means of physical characterization and contrastdetail analysis,” Med Phys, vol. 33, no. 11, pp. 4198-4209, 2006.
S. Rivetti, N. Lanconelli, M. Bertolini, D. Acchiappati, “A new clinical unit for digital radiography based on a thick amorphous selenium plate: physical and psychophysical characterization,” Med Phys, vol. 38, no. 8, pp. 4480-4488, 2011.
G. Borasi, A. Nitrosi, P. Ferrari, D. Tassoni, “On site evaluation of three flat panel detectors for digital radiography,” Med Phys., vol. 30, no. 7, pp. 1719-1731, 2003.
IEC 62220-1, “Medical electrical equipment - Characteristics of digital x-ray imaging devices - Part 1: Determination of the detective quantum efficiency,” IEC International Electrotechnical Commission (IEC), Geneva: Switzerland, 2003.
J.T. III. Dobbins, E. Samei, N.T. Ranger, Y. Chen, “Intercomparison of methods for image quality characterization. II. Noise power spectrum,” Med Phys., vol. 33, no. 5, pp. 1466-1475, 2006.
N.W. Marshall, “A comparison between objective and subjective image quality measurements for a full field digital mammography system,” Phys Med Biol., vol. 51, no. 10, pp. 2441-2463, 2006.
https://imagej.nih.gov/ij/
U. Neitzel, S. Günther-Kohfahl, G. Borasi, E. Samei, “Determination of the detective quantum efficiency of a digital x-ray detector: comparison of three evaluations using a common image data set,” Med Phys, vol. 31, no. 8, pp. 2205-2211, 2004.
NHSBSP (National Health Service Breast Screening Programme), “Calculation of quantitative image quality parameters,” NHSBSP Equipment Report 0902 (Sheffield: NHSBSP Publications), 2009.