Airport body scanners use a technology called Advanced Imaging Technology (AIT) for full-body scans at airport checkpoints. They are designed to detect metallic and non-metallic threats in a matter of seconds, such as weapons like knives, guns, and explosives. Unlike metal detectors, full-body scanners can detect non-metal objects, which became an increasing concern after various airliner bombing attempts in the 2000s. Some scanners can also detect swallowed items or items hidden in body cavities of a person. There are two types of body scanners: the millimeter wave scanner and the backscatter X-ray. The millimeter wave scanner uses high frequency radio waves to make an image of the body which shows objects hidden under clothes. The backscatter X-ray scanners detect the radiation that reflects from the human body.

When a person steps into the machine, places their feet on the footprints, and puts their arms over their head, the scanner creates an image of the persons body. The image is not a photograph but a cartoon-like representation of the persons body. TSA agents who view the display screen from the full-body scanner cannot see passengers naked. If the scanner detects something out of the ordinary, the screen will display an image of the area of the body where the object was detected. However, body scanners would not pick up anything else stashed inside a body cavity, such as drugs or hazardous liquids. These items might be detected, however, if they were in a persons pockets.