1. A scanning unit for examining contents of an object, the scanning unit comprising: a first path through the scanning unit to transport an object; at least one source of a beam of radiation, the at least one source being movable across a second path transverse to the first path, the second path being within a first region extending partially around the first path; and a stationary detector in a second region extending partially around the first path, the detector array being positioned to detect radiation transmitted through the object during scanning.