Monte Carlo modeling of a conventional X-ray computed tomography scanner for gel dosimetry purposes


Hayati H., Mesbahi A., Nazarpoor M.

RADIOLOGICAL PHYSICS AND TECHNOLOGY, vol.9, no.1, pp.37-43, 2016 (ESCI, Scopus) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 9 Issue: 1
  • Publication Date: 2016
  • Doi Number: 10.1007/s12194-015-0331-4
  • Journal Name: RADIOLOGICAL PHYSICS AND TECHNOLOGY
  • Journal Indexes: Emerging Sources Citation Index (ESCI), Scopus
  • Page Numbers: pp.37-43
  • Keywords: X-ray computed tomography, Monte Carlo simulation, Gel dosimetry
  • Dokuz Eylül University Affiliated: No

Abstract

Our purpose in the current study was to model an X-ray CT scanner with the Monte Carlo (MC) method for gel dosimetry. In this study, a conventional CT scanner with one array detector was modeled with use of the MCNPX MC code. The MC calculated photon fluence in detector arrays was used for image reconstruction of a simple water phantom as well as polyacrylamide polymer gel (PAG) used for radiation therapy. Image reconstruction was performed with the filtered back-projection method with a Hann filter and the Spline interpolation method. Using MC results, we obtained the dose-response curve for images of irradiated gel at different absorbed doses. A spatial resolution of about 2 mm was found for our simulated MC model. The MC-based CT images of the PAG gel showed a reliable increase in the CT number with increasing absorbed dose for the studied gel. Also, our results showed that the current MC model of a CT scanner can be used for further studies on the parameters that influence the usability and reliability of results, such as the photon energy spectra and exposure techniques in X-ray CT gel dosimetry.