A prototype of high resolution parallel beam Optical Computed Tomography scanner

Abstract

Introduction There is a pressing need for a three-dimensional (3D) dosimetry system, appropriate for clinical use, to enable comprehensive verification of the dose distributions typical of modern radiation therapy. Purpose For this aim we introduced a dosimetry system that consist of a polymer gel dosimeter (MAGIC-F) and a prototype of laboratory dedicated level Optical Computed Tomography (OCT) scanner. Materials and methods The OCT was designed and constructed based on a broad beam visible light source and a two-dimensional charge-coupled device (CCD) detector. In this study spatial resolution parameter was determined. One of the methods for evaluating the spatial resolution of an optical CT scanner is to calculate the modulation transfer function (MTF). Results The system could scan a sample around 25 min completely then a set of cross sectional images is reconstructed from projections. The reconstructed images from optical scanner were analyzed to evaluate spatial resolution. The result indicated 10% modulation was 3.6 cycle/mm. That is means the system has sub millimeter resolution. Conclusion It has been observed that the prototype Optical parallel beam scanner is reliable the perspective of resolution for scanning gels for radiotherapy applications. The cost of fabrication scanner is lower than the commercial models. This scanner is a laboratory dedicated level Optical Computed Tomography of course it can be improved and develop in future.