A scanning unit for inspecting objects comprises in one example a radiation source, a movable platform to support an object, and a detector positioned to receive radiation after interaction of radiation with the object. The platform is movable at least partially within a cavity defined, at least partially, below at least one of the source or the detector. In another scanning unit, a first conveyor conveys an object to a movable platform, and second and third conveyors convey the object from the platform. The second and third conveyors are at different vertical heights. In another scanning unit, images from an energy sensitive detector and a spatial detector are fused. In a method, scanning parameters during CT scanning are changed and images reconstructed before and after the change. In another method, an object is scanned with X-ray beams having first and second energy distributions, generated by the same X-ray source.