Non-intrusive inspection systems, including apparatuses and methods, for non-intrusively inspecting cargo containers employed, generally, in the cargo transportation industry. The non intrusive inspection systems utilize one or more, single or multi-energy electron accelerators arranged in a plurality of different arrangements and orientations to provide two and, essentially, three dimensional views of the contents of (i.e., objects within) a cargo container and to enable discrimination and identification of materials present within the contents thereof.