Patent ID: 7257188
Filing Date: 2007-08-14
Classification: G01N,G01T,G01V

Abstract:
1. A method of examining contents of an object, the method comprising: scanning first portions of the object with a first radiation beam at a first energy; detecting first radiation after interaction of the first radiation beam with the first portions, wherein projections of at least a portion of the first radiation beam through each portion, onto a detector, define respective first pixels; scanning second portions of the object with a second radiation beam at a second energy different than the first energy; detecting second radiation after interaction of the second radiation beam with the second portions, wherein projections of at least a portion of the second radiation beam through each portion, onto a detector, define respective second pixels; calculating first functions of the radiation detected at the first and second energies, for corresponding first and second pixels; grouping first functions of a plurality of corresponding pixels into at least one group; calculating a second function based, at least in part, on the first functions of at least certain of the plurality of pixels in the at least one group; and determining whether the object at least potentially contains material having a high atomic number (“high atomic number material”) greater than a predetermined atomic number, based, at least in part, on the second function of the at least one group.