title: Monte Carlo modeling of a conventional X-ray computed tomography scanner for gel dosimetry purposes.
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.
authors.affiliation: International Branch of Tabriz University of Medical Sciences (ARAS), Tabriz, Iran.
authors.forename: Homa
authors.initials: H
authors.lastname: Hayati
authors.affiliation: Medical Physics Department, Medical School, Tabriz University of Medical Sciences, Tabriz, Iran. mesbahiiran@yahoo.com.|Medical Physics Department, Institute of Health Sciences, Dokuz Eylul University, Izmir, Turkey. mesbahiiran@yahoo.com.
authors.forename: Asghar
authors.identifier: http://orcid.org/0000-0001-9159-2168
authors.initials: A
authors.lastname: Mesbahi
authors.affiliation: International Branch of Tabriz University of Medical Sciences (ARAS), Tabriz, Iran.|Faculty of Paramedicine, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran.
authors.forename: Mahmood
authors.initials: M
authors.lastname: Nazarpoor
mesh_terms: D005782:Gels; D007091:Image Processing, Computer-Assisted; D009010:Monte Carlo Method; D017785:Photons; D011874:Radiometry; D015898:Tomography Scanners, X-Ray Computed
chemical_list: D005782:Gels
keywords: Gel dosimetry; Monte Carlo simulation; X-ray computed tomography