Dosimetry for MARS

Abstract

MARS spectral CT is an up and coming imaging modality which shows great promise in revealing unique diagnostic information and industrial analysis techniques. Because this imaging modality based on X-ray CT, it is of utmost importance to study the radiation dose aspects of its use. Moreover, the capabilities of spectral imaging show potential for a new method in 3D dosimetry, one which is personalized. This thesis reports on the use of Monte Carlo simulation tool TOPAS in estimating the dose to a sample scanned with the pre-clinical MARS scanner, and the results are experimentally verified using an ion chamber and TLDs. Use of EPDs in characterizing radiation within the gantry was also investigated. In addition, a pilot study was conducted into a potential algorithm a future onboard personalized dosimetry system may utilize. On the whole, all dosimetry techniques indicate a MARS scan dose on the order of 20 mGy.