The potential of medical imaging modalities to identify a concealed energetic materials device

Abstract

The act of terrorism has received much attention in recent years. In this study, a technique was investigated to identify concealed energetic materials which could aid in reducing the threat of terrorism and save innocent lives. Using different X-ray source and detector technologies for imaging, a variety of medical imaging modalities in Charlotte Maxeke Academic Hospital (CMJAH) are investigated as a potential to identifying concealed materials. An inert dummy improvised explosive device (IED) was built in the form of a handheld briefcase. The IED and an Electronic Portal Imaging Device (EPID) Quality Control (QC) phantom were imaged using the Toshiba medical simulator, Orthovoltage teletherapy machine, Cobalt 60 (60Co) teletherapy machine, Linear Accelerator (Linac), and Computed Tomography (CT) scanner. Detection methods used were Kodak X-Omat V ready pack film, Fuji medical X-ray film, Gafchromic film, and an EPID. The low energy from the simulator was absorbed by the high-density materials in the briefcase. The image had high contrast, and since this was planar imaging hidden, materials were not visible. The CT scanner contained many streak artefacts, producing poor 3D images of the briefcase. At high energies the Linac and 60Co teletherapy machine penetrated through the thick materials, displaying underlying and overlying materials on the image. The modality which had the best balance between contrast and spatial resolution was the orthovoltage teletherapy machine. The orthovoltage teletherapy machine, being the only modality to display all the materials of the IED has the potential to be used as a modality to identify a concealed energetic materials device.