3D body scanners at Australian airports: what are they and how do they work?

Passengers are asked to stand in the body scanner with arms raised while the machine rotates around them, looking for anything they may be carrying under their clothing. Photograph: Bertrand Guay/AFP/Getty Images

Sydney airport has just begun using 3D body computed tomography scanners in its Qantas domestic terminal, T3. Though CT scanners have been widely used in international terminals in Australia for several years, and are in place in Melbourne’s T4 terminal and at Gladstone and Canberra airports, it is the first time many passengers have seen the technology at a domestic airport.

What are the scanners, and how do they work?