The present specification discloses systems for a compact and portable X-ray transmission imaging system that is used for security inspection of small items. The system includes a housing with an X-ray tunnel for receiving an article to be inspected, a conveyor for conveying the article through the tunnel, a dual source X-ray system, with a central target, for generating two overlapping cone beams, and a two-dimensional X-ray detector system for detecting the generated dual energy X-rays.