Flat sheet of Zinc material as a filter for gamma photons in Tc-99mm SPECT imaging

  • Authors

    • Nazifah Abdullah
    • Inayatullah Shah Syed
    • Ahmad Zakaria
    2018-10-07
    https://doi.org/10.14419/ijet.v7i4.15.23018
  • Material Filter, Scatter Correction, SPECT Image Quality, Contrast

  • Purpose of the Study: Scattered gamma photons in single photon emission computed tomography (SPECT) is one of the main issues that degrade the image quality. There are several types of scatter correction methods. However, none of the technique is applied in routine clinical Tc-99m SPECT imaging. Therefore, Zinc (Zn) material filter was constructed for pre-filtration of scattered gamma photons in Tc-99m single photon emission computed tomography (SPECT).

    Materials and Methods: Tc-99m radioactivity was administered into the Carlson’s phantom. Planar and tomographic data were acquired with and without hot regions insert, respectively, with and without material filter. Scatter to non-scatter ratio was measured from the photopeak region of Tc-99m spectra. Tomographic images were generated using filtered back projection method. Contours on images were drawn with ImageJ software. Images obtained with and without material filter were analysed in terms of detectability of hot regions.

    Results: Remarkable decrease (≈ 21%) in the ratio of scattered to non-scattered gamma photons with material filter was achieved. Detectability of smaller hot regions with material filter was enhanced. In terms of sizes of all hot regions, material filter results appear closer to the original sizes.

    Conclusion: Material filter technique could be applied in Tc-99m clinical SPECT, while organ phantom studies are needed.

        

  • References

    1. [1] Hutton BF, Buvat I, Beekman FJ. Review and current status of SPECT scatter correction. Phys Med Biol 2011;56: R85-R112.

      [2] Cherry SR, Sorenson JA, Phelps ME. Physics in Nuclear Medicine, 4th ed Elsevier Saunders: Philadelphia; 2012.

      [3] Shidahara M, Watabe H, Kim KM, Kato T, Kawatsu S, Kato R. et al. Development of a practical image-based scatter correction method for brain perfusion SPECT: comparison with the TEW method. Eur J Nucl Med Mol Imaging 2005;32: 1193-98.

      [4] Pillay M, Shaprio B, Cox PH. The effect of an alloy filter on gamma camera images. Eur J Nucl Medicine 2005;12: 293-96.

      [5] Pillay M, Manon RS. Filter for Gamma Ray Camera. US Patent, 4,852,142; 1989.

      [6] Sayed IS. Use of a Tin (Sn) Flat Sheet as a Material Filter for Reduction of Scattered Gamma Photons and Enhancement of Cold Regions Image Quality in Tc-99m SPECT. International Journal of Computing Academic Research 2016;5: 110-21.

      [7] Sayed IS, Siti Zawani H. Effects of Copper 0.127 mm Thick Flat Sheet on Uniform and Hot Region Images as a Material Filter for Scatter Correction in Tc-99m SPECT. International Journal of Computing Academic Research 2016;5: 143-49.

      [8] Nazifah A, Norhanna S, Shah SI, Zakaria A. Effect of different thickness of material filter on Tc-99m spectra and performance parameters of gamma camera. Journal of Physics: Conference Series 2014;546: 1- 6.

      [9] Zakaria NN. BSc Dissertation, International Islamic University Malaysia; 2013.

      [10] Ogawa K, Harata Y, Ichihara T, Kubo A, Hashimoto S. A practical method for position dependent Compton scatter correction in single photon emission CT A practical method for position dependent Compton scatter correction in single photon emission CT. IEEE Trans Med Imaging 1991;10: 408-12.

      [11] International Atomic Energy Agency, IAEA Human Health Series No. 6, IAEA, Vienna; 2009.

      [12] Lyra M, Ploussi A, Rouchota M, Synefia S. Filters in 2D and 3D Cardiac SPECT Image Processing. Cardiol Res Pract 2014; 2014: 963264.

      [13] Jaszczak RJ, Floyd CE, Coleman RE. Scatter compensation techniques for SPECT. IEEE Trans. Nuclear Sci 1985;32: 786-93.

      [14] Harris CC, Greer KL, Jaszczak RJ, Floyd CEJ, Fearnow EC, Coleman RE. Technitium-99m attenuation coefficients in water filled phantom determined with gamma cameras. Med Phys 1984;11: 681-85.

      [15] Rasband WS. ImageJ. United States National Institutes of Health, Bethesda, Maryland, USA; 1997 – 2018.

      [16] Larsson SA, Axelsson B, Dahl CM, Msaki P. The use of 1-D and 2-D scatter deconvolution techniques for contrast enhancement and quantification in SPECT. J Nucl Medicine 1986;27: 884.

      [17] Kojima M, Masanori, Mutsumasa T. Experimental analysis of scattered photons in Tc-99m imaging with a gamma camera. Ann Nucl Med 1991; 5:139 - 44.

      [18] Sayed IS, Fong SY, Farhana M, Nurul Farizan M Z. 2016. Effects of Unconventional (Material) Filters on the Quality of Images Produced by Three Gamma Camera Systems in Tc-99m SPECT. International Journal of Healthcare Sciences 2016;4: 203-09.

      [19] Sayed IS, Siti Zubaidah M. Use of an Effective Attenuation Coefficient Value and Material Filter Technique for Scatter Correction in Tc-99m SPECT. International Journal of Computing Academic Research 2016;5: 163-69.

  • Downloads

  • How to Cite

    Abdullah, N., Shah Syed, I., & Zakaria, A. (2018). Flat sheet of Zinc material as a filter for gamma photons in Tc-99mm SPECT imaging. International Journal of Engineering & Technology, 7(4.15), 311-314. https://doi.org/10.14419/ijet.v7i4.15.23018