Development of a Coded-aperture Gamma Camera for Monitoring of Radioactive Materials

방사성 물질 감시를 위한 부호화 구경 감마카메라 개발

  • Published : 2004.12.30


A coded-aperture gamma camera was developed to increase the sensitivity of a pin hole camera made with a pixellated CsI(Tl) scintillator and a position-sensitive photomultiplier tube. The modified round-hole uniformly redundant array of pixel size $13{\times}11$ was chosen as a coded mask considering the detector spatial resolution. The performance of the coded-aperture camera was compared with the pin hole camera using various forms of Tc-99m source to see the improvement of signal-to-noise ratio or the improvement of the sensitivity. The image quality is much improved despite of a slight degradation of the spatial resolution. Though the camera and the test were made for low energy case, but the concept of the coded-aperture gamma camera could be effectively used for the radioactive environmental monitoring and other applications.


  1. E.E. Fenimore and T.M. Cannon, 'Coded aperture imaging with uniformly redundant arrays', Appl. Opt., 17, 337(1978)
  2. S.R. Gottesman and E.E. Fenimore, 'New family of binary arrays for coded aperture imaging', Appl. Opt., 29, 4344(1989)
  3. S.R. Gottesman and E.J. Schneid, 'PNP-A New Class of Coded Aperture Arrays', IEEE Trans. Nucl. Sci. NS-33, 745-749(1986)
  4. K. Byard, 'On self-supporting coded aperture arrays,' Nucl. Instr. and Meth. A 322, 97-100(1992)
  5. R. Accorsi, F. Gasparini and R.C. Lanza, 'Optimal coded aperture patterns for improved SNR in nuclear medicine imaging', Nucl. Instr. and Meth. A 474, 273-284(2001)
  6. W. Lee, G. Cho, and H. Kim, 'A radiation monitoring system with capability of the gamma camera imaging and the estimation of exposure dose rate,' IEEE Trans. Nuc. V.49(3), 1547-1551(2002)
  7. E.E. Fenimore, 'Coded aperture imaging: predicted performance of uniformly redundant arrays', Appl, Opt., 17, 2562(1978)