Evaluation of the performance of parallel-hole collimator for high resolution small animal SPECT: A Monte Carlo study

Document Type : Original Article


Department of Physics, Faculty of Science, University of Guilan, Rasht, Iran


Introduction: Image quality and accuracy of in vivo activity quantification in SPECT are affected by collimator penetration and scatter components, especially in high energy imaging. These phenomena highly depend on the collimator characteristic and photon energy. The presence of penetrated and scattered photons from collimator in SPECT images degrades spatial resolution, contrast and image quality. Knowledge of penetration and scatter distribution is essential for optimization of collimator design and development of reconstruction algorithms.The aim of this study to survey the collimator performance of the newly developed HiReSPECT dual head gamma camera with pixelated array CsI(Na).
Methods:We modeled the HiReSPECT, by using SIMIND Monte Carlo simulation code. The contribution of geometric, scatter and penetration components were quantitatively calculated for the different energy sources. Then we compared these results with simulation results of another small animal SPECT with compact pixelated array CsI(Tl) detector.
Results:The simulated System spatial resolution and energy resolution of the HiReSPECT at 140keV respectively are 1.9mm and 29.72 keV (21.23%) FWHM  at 2.5cm distance from detector surface also Geometric, penetration, and scatter at 140keV for the HiReSPECT collimator are 96.42%, 2.22%, 1.30%, respectively. Similarly, geometric, penetration, and scatter at 159keV and 245keV for this system collimator are (95.24%, 3.08%, 1.68%) and (87.21%, 8.10%, 4.69%), respectively.
Conclusion: The results verified that the magnitude of these components depend on collimator geometric structure and photons energy. The measured performances indicated that the HiReSPECT scanner is well suited for preclinical molecular imaging research and provide high resolution for small animal imaging.


Main Subjects

  1. Lu Y, Chen L, Gindi G. Collimator performance evaluation for In-111 SPECT using a detection/localization task. Phys Med Biol. 2014;59(3):679-96.
  2. De Vries DJ, Moore S. Approximation of Approximation of hexagonal holes by square holes in Monte Carlo simulation of gamma-camera collimation.    IEEE Trans Nucl Sci. 2002;49(5):2186-95.
  3. Polo IO. Evaluation of the scattered radiation components produced in a gamma camera using Monte Carlo method. Braz J Biom Eng. 2014;30(2):179-188.
  4. Ljungberg M, Larsson A, Johansson L. A New Collimator simulation in SIMIND Based on the delta-scattering technique. IEEE Trans Nucl Sci. 2005; 52(5):1370-75.
  5. Sundin K, Ljungberg M. SIMIND based pinhole imaging: development and validation IEEE Nucl Sci Symp Conf Rec. 2007;5:3998-4005.
  6. Shafaei M, Ay MR, Sardari D, Dehestani N, Zaidi H. Monte Carlo assessment of geometric, scatter and septal penetration components in DST-XLi HEGP collimator. IFMBE Proceedings. 2008; 22:2479–82.
  7. Fleming JS, Alaamer AS. Influence of collimator characteristics on quantification in SPECT. J Nucl Med. 1996 Nov;37(11):1832-6.
  8. He X, Frey E, Links J,  Song  X, Tusi B. Comparison of  penetration and scatter effects on defect contrast for GE and Siemens LEHR collimators in myocardial perfusion SPECT—A simulation study. IEEE Trans Nucl Sci. 2005;52(5):1359- 64.
  9. Pandey AK, Sharma SK, Karunanithi S, Kumar P, Bal C, Kumar R. Characterization of parallel-hole collimator using Monte Carlo Simulation. Indian J Nucl Med. 2015 Apr-Jun;30(2):128-34.
  10. Green MV, Seidel J, Vaquero JJ, Jagoda E, Lee I, Eckelman WC. High resolution PET, SPECT and projection imaging in small animals. Comput Med Imaging Graph. 2001 Mar-Apr;25(2):79-86.
  11. Xi W, Seidel J, Kakareka JW, Pohida TJ, Milenic DE, Proffitt J, Majewski S, Weisenberger AG, Green MV, Choyke PL. MONICA: a compact, portable dual gamma camera system for mouse whole-body imaging. Nucl Med Biol. 2010 Apr;37(3):245-53.
  12. Magota K, Kubo N, Kuge Y, Nishijima K, Zhao S, Tamaki N. Performance characterization of the Inveon preclinical small-animal PET/SPECT/CT system for multimodality imaging. Eur J Nucl Med Mol Imaging. 2011 Apr;38(4):742-52.
  13. Weisenberger A, Bradley E, Majewski S, Saha M. Development of a novel radiation imaging detector system for in vivo gene imaging in small animal studies. IEEE Trans Nucl Sci. 1998;45(3):1743–49.
  14. Pashazadeh AM, Tanha K, Jafarian-Dehkordi F, Assadi M, Moji V, Zeraatkar N, Ay MR. Experimental evaluation of the performance of HiReSPECT scanner: A high-resolution SPECT system for small animal imaging. Front Biomed technol. 2014;1(3):222-27.
  15. Moji V, Zeratkar N, Farahani MH, Aghamiri MR, Sajedi S, Teimourian B, Ghafarian P, Sarkar S, Ay MR. Performance evaluation of a newly developed high-resolution, dual-head animal SPECT system based on the NEMA NU1-2007 standard. J Appl Clin Med Phys. 2014;15(6):4936.
  16. Sajedi S, Zeraatkar N, Moji V, Farahani MH, Sarkar S, Arabi H, Teymoorian B, Ghafarian P, Rahmim A, Ay MR. Design and development of a high resolution animal SPECT scanner dedicated for rat and mouse imaging. Nucl Instrum Methods Physic Res. 2014;741:169–76.
  17. Zeraatkar N, Sajedi S, Farahani MH, Arabi H, Sarkar S, Ghafarian P, Rahmim A, Ay MR. Resolution-recovery-embedded image reconstruction for a high-resolution animal SPECT system. Phys Med. 2014 Nov;30(7):774-81.
  18. Lazaro D, Buvat I, Loudos G, Strul D, Santin G, Giokaris N, Donnarieix D, Maigne L, Spanoudaki V, Styliaris S, Staelens S, Breton V.  Validation of the GATE Monte Carlo simulation platform for modelling a CsI(Tl) scintillation camera dedicated to small-animal imaging. Phys Med Biol. 2004 Jan 21;49(2):271-85.
  19. Giokaris N,  Loudos G, Maintas D, Karabarbounis A, Spanoudaki V, Stiliaris E, Boukis S, Gektin A, Boyarintsev A, Pedash V, Gayshan V. Crystal and collimator optimization studies of a high-resolution γ-camera based on a position sensitive photomultiplier. Nucl Instrum Methods Phys Res, Sect A. 2004;527(1):134–9.
  20. Khosravi HR, Sarkar S, Takavar A , Saghari M, Shahriari M. Planar and SPECT Monte Carlo acceleration using a variance reduction technique in I-131 imaging. Int J radiat Res. 2007;4(4):175-82.
  21. Zeniya T, Watabe H, Aoi T, Kim KM, Teramoto N, Takeno T, Ohta Y, Hayashi T, Mashino H, Ota T, Yamamoto S, Iida H. Use of a compact pixellated gamma camera for small animal pinhole SPECT imaging.  Ann Nucl Med. 2006 Jul;20(6):409-16.
  22. Pirayesh Islamian J, Bahreyni Toossi MT, Momennezhad M, Zakavi R, Sadeghi R . Monte Carlo study of the effect of backscatter material thickness on 99mTc source response in single photon emission computed tomography. Iran J Med Phys. 2013;10(1):69-77.
  23. Pirayesh Islamian J, Bahreyni Toossi MT, Momennezhad M, Naseri SH, Ljungberg M. Simulation of a quality control Jaszczak phantom with SIMIND Monte Carlo and adding the phantom as an accessory to the program.  Iran J Med Phys.  2012;9(2):135-40.
  24. Ljungberg M. The SIMIND Monte Carlo program Home Page. http://www2.msf.lu.se/simind.
  25. Knoll GF. Radiation detection and measurement. 4nd ed. New York: John Wiley & Sons, Inc; September 2010.
  26. Khalil M. Basic sciences of nuclear medicine. New York: Springer-Verlag; 2011.
  27. Holstensson M, Partridge M, Buckley SE, Flux GD. The effect of energy and source location on gamma camera intrinsic and extrinsic spatial resolution: an experimental and Monte Carlo study. Phys Med Biol. 2010 Mar 21;55(6):1735-51.
  28. Sprawls P. Physical principles in medical imaging. 2nd ed. Madison: Medical Physics Publishing; 2000.
  29. Rajaee A,  Shahriari M,  Kamali Asl A, Hosseini SH. Simulation study of the influence of collimator material on image quality improvement for high energy photons in nuclear medicine using MCNP code. J Theor Appl Phys. 2011;4(4):13-18.
  30. Autret D, Bitar A, Ferrer L, Lisbona A, Bardiès M. Monte Carlo modeling of gamma cameras for I-131 imaging in targeted radiotherapy. Cancer Biother Radiopharm. 2005 Feb;20(1):77-84.
  31. Dewaraja YK, Ljungberg M, Koral KF. Characterization of scatter and penetration using Monte Carlo simulation in 131I imaging. J Nucl Med. 2000 Jan;41(1):123-30.
  32. Pirayesh Islamian J, Bahreyni Toossi M.T, Momennezhad M, Naseri Sh, Ljungberg M. Monte Carlo study of the effect of collimator thickness on Tc-99m source response in single photon emission computed tomography. World J Nucl Med. 2012;11(2):70-74.