Transparent security

Imperial College in London has devised an airport X-ray scanner that examines
passengers’ luggage with the accuracy of a CT scanner, but at much lower cost
(GB 2 315 546). The luggage conveyor belt is ringed by 15 X-ray sources,
arranged along its length so that each piece of baggage is scanned from all
angles. The scans are merged to form a three-dimensional image with 15 times the
resolution of a conventional 2-D airport scan. The image reveals the density of
suspect objects, as well as their shape.