Enhanced threat detection in three dimensions: An image-matched comparison of computed tomography and dual-view X-ray baggage screening

Computed Tomography (CT) is increasingly used in screening of cabin baggage in airports. The current study aimed to establish whether screening with CT confers a detection advantage over dual-view (DV) X-ray when resolution is controlled. We also evaluated whether a ‘targetless’ search strategy – in which screeners identify and reject safe items – improved detection relative to target-based methods. In an online study, 104 novice screeners were trained with either CT or DV, and either a targetless or a target-based search strategy. Screeners were then tested in a simulated cabin baggage screening task. CT screeners performed with greater sensitivity than DV screeners. Search strategy did not affect sensitivity, although the target-based strategy resulted in a more liberal criterion. We conclude that CT imaging confers a benefit to screening performance over DV when image resolution is controlled. This is likely due to the ability to rotate the image to resolve occlusions.