Modern airport security uses CT scanners to create detailed 3D images of your luggage.

Computed Tomography (CT) technology was originally developed for medical imaging in the 1970s by Sir Godfrey Hounsfield and Allan Cormack. While traditional airport X-rays produce a flat 2D image, CT scanners utilize a spinning Gantry that houses an X-ray source and detectors. As your bag moves through the tunnel, the machine captures hundreds of individual views to reconstruct a volumetric 3D model.One of the most critical features of these scanners is the ability to measure the 'Hounsfield unit' or the specific density of objects. This allows the system's software to automatically flag materials that match the atomic footprint of known explosives or hazardous liquids. This automated detection is significantly more accurate than human observation of 2D images alone.The Transportation Security Administration (TSA) began a massive rollout of these scanners in 2019, partnering with companies like Smiths Detection and L3Harris. By 2023, hundreds of these units were installed in major hubs like London Heathrow and New York’s JFK. Because the 3D images are so clear, passengers in many airports no longer need to remove laptops or 100ml liquid containers, significantly increasing passenger throughput.