The present invention is a self-contained mobile inspection system and method and, more specifically, improved methods and systems for detecting materials concealed within a wide variety of receptacles and/or cargo containers. In particular, the present invention is an improved method and system with a novel boom structure that reduces the weight of the boom. The single, light-weight boom of the inspection system is relatively compact in a stowed configuration and has a low height and center of gravity lending to greater maneuverability.