Advancements in X-ray imaging technologies for enhancing airport security and operational efficiency in air transportation

X-ray imaging remains the most popular technology in aviation security screening to date, and recent advances in imaging hardware, particularly in computed tomography (CT) technology, as well as artificial intelligence (AI) assistance in threat analysis, have enhanced screening capabilities while also introducing new challenges. This paper presents a comprehensive and application-focused review of X-ray screening technology and AI-assisted threat analysis in air transport security. The review encompasses the background of X-ray imaging technology, the integration of AI for automated and semi-automated threat analysis, and the characteristics of typical datasets and approaches. Unlike the past reviews, which mainly focused on the algorithmic aspects, this review offers a focus on the operational context through the review of passenger checkpoint screening, checked baggage screening, and cargo screening as individual application domains. Case studies from large international airports and smaller airports across the world are used to illustrate the effect of throughput requirements, infrastructure, and budget on deployment. Finally, the article offers the necessary future research directions to improve robustness, generalization, and human-centric system design for AI-assisted X-ray screening systems. This provides a comprehensive resource for researchers, system developers, and aviation experts to address the existing gap between technological development and operationalization in security.