Iranian Journal of Nuclear Medicine

Iranian Journal of Nuclear Medicine

An alternative mathematical modeling of the scintillation camera and framework for performance analysis of gamma-ray positioning algorithms

Document Type : Original Article

Authors
Behnoosh Teimourian Fard 1, 2
Mojtaba Shamsaei Zafarghandi 1
Soheil Hosseini 2
Hamid Sabet 3
Mohammad Reza Ay 2, 4
1 Department of Energy Engineering and Physics, Amirkabir University of Technology, Tehran, Iran
2 Research Center for Molecular and Cellular Imaging, Tehran University of Medical Sciences, Tehran, Iran
3 Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
4 Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran, Iran
Abstract
Introduction: Substantive amount of work has been done in modeling and analyzing the scintillation camera system processes including positioning and image formation. The goal of this work is to develop a framework for analyzing performance of nonlinear positioning methods upon construction of a mathematical model of the system. In this study, the photodetector array counts are assumed to follow a multinomial distribution.
Methods: We studied effects of several parameters on system performance, including photomultiplier tube (PMT) non-uniform response, gains, shape, size and positioning methods. This was done by constructing linearity and resolution maps, feeding the system a uniform grid of point sources showing the distorted output along with associated blurring intensity. The spatial resolution and linearity parameters are used to evaluate the performance of simulated scintillation camera.
Results:The study findings revealed that the square PMT is the best option due to better fitting and quality especially near the edge of the detector and also ability to cover the rectangular crystal area with minimum numbers of PMTs. Also, the resolution resulted from CSE is 5% and 20% better than center of mass and modified center of mass respectively.
Conclusion: We showed that the rectangular gamma camera accompanied by an array of square PMTs can introduce the optimum performance regarding linearity and resolution if the nonlinear method, called CSE, is used as positioning method. Further evaluation is needed to evaluate the performance of the proposed gamma camera in practice.
Keywords
Gamma camera
Square PMT
Mathematical modeling
Multinomial distribution
Nonlinearity Map
Correlated signal enhancement
Subjects
  1. Anger HO. Scintillation camera. Rev Sci Instrum. 1958;29(1):27-33.
  2. Anger HO. Scintillation camera with multichannel collimators. J Nucl Med. 1964 Jul;5:515-31.
  3. Bushberg JT, Seibert JA, Leidholdt EM, Boone JM. Essential physics of medical imaging. 2nd ed. Philadelphia: Lippincott Williams & Wilkins; 2002.
  4. Peterson TE, Furenlid LR. SPECT detectors: the Anger camera and beyond. Phys Med Biol. 2011 Sep 7;56(17):R145-82.
  5. Svedberg JB. On the intrinsic resolution of a gamma camera system. Phys Med Biol. 1972 Jul;17(4):514-24.
  6. Svedberg JB. Computer simulation of the Anger gamma camera. Comput Programs Biomed. 1975 Mar;4(3):189-201.
  7. Svedberg JB. Image quality of a gamma camera system. Phys Med Biol. 1968 Oct;13(4):597-610.
  8. Baker RG, Scrimger JW. An investigation of the parameters in scintillation camera design. Phys Med Biol. 1967 Jan;12(1):51-63.
  9. Hunter WCJ: Modeling stochastic processes in gamma-ray imaging detectors and evaluation of a multi-anode PMT scintillation camera for use with maximum-likelihood estimation methods. PhD thesis. Department of Physics, The University of Arizona; 2007.
  10. Sain JD: Optical modeling, design optimization, and performance analysis of a gamma camera for detection of breast cancer. PhD thesis. The University of Arizona; 2001.
  11. Barrett HH, Hunter WC, Miller BW, Moore SK, Chen Y, Furenlid LR. Maximum-likelihood methods for processing signals from gamma-ray detectors. IEEE Trans Nucl Sci. 2009 Jun 1;56(3):725.
  12. Fessler JA. Statistical image reconstruction methods. In: Fitzpatrick JM, Sonka M. Handbook of medical imaging, volume 2. Medical image processing and analysis. Spie Press Book;2000. P. 1-71.
  13. Jansen FP, Binnie DM. Signal processing in scintillation cameras for nuclear medicine. Patent 5,504,334, 1996.
  14. Anger HO. Sensitivity, resolution, and linearity of the scintillation camera. IEEE Trans Nucl Sci. 1966;13(3):380-392.
  15. Tanaka E, Hiramoto T, Nohara N. Scintillation cameras based on new position arithmetics. J Nucl Med. 1970 Sep;11(9):542-7.
  16. Hwang AB, Iwata K, Hasegawa BH. Simulation of depth of interaction effects for pinhole SPECT. IEEE Nucl Sci Symp Conf Rec. 2001;3:1293-1297.
  17. Korevaar MAN: High-resolution EM-CCD scintillation gamma cameras. PhD thesis. Delf University of Technology; 2013.
  18. Zeraatkara N, Sajedia S, Teimourian Farda B, Kaviania S, Akbarzadeh A, Farahani MH, Sarkar S, Ay MR. Development and calibration of a new gamma camera detector using large square photomultiplier tubes. J Instrum. 2017;12(9):P09008.