A system for scanning a form of interest, while the form of interest is in motion, is provided. The system comprises a first detector panel-pair, comprising a first detector panel and a second detector panel, spatially offset from the first detector panel by a first continuous passageway for the motion of the form of interest. A second detector panel-pair comprises a third detector panel and a fourth detector panel, spatially offset from the third detector panel by a second continuous passageway for the motion of the form of interest, and a location-tracking device adapted to monitor the location of the form of interest.