Patent ID: 7260173

Claim:
A hazardous material detection system comprising: a gantry provided with an X-ray source and an X-ray sensor which are disposed in opposition to each other, wherein the X-ray source comprises a cable for supplying power and the X-ray sensor comprises a cable for outputting a signal and wherein the gantry swings forward and backward on a circular arc around an inspection subject but does not continuously rotate; a belt-conveyor which conveys the inspection subject wherein the belt-conveyor comprises a first conveyor in front of the gantry and a second belt-conveyor in rear of the gantry; a calculating unit which calculates a computed tomography (CT) value by swinging the gantry forward and backward along the circular arc around the inspection subject along said circular arc and picking up a CT image of the inspection subject; and a display unit which displays the X-ray absorption coefficient and the CT value, wherein the CT image is obtained by use of a particular configuration of the gantry which allows the gantry to rotate at least 330 degrees.