1. A method for screening a cargo container, said method being implemented by a computing apparatus having a processor, said method comprising: a) receiving at said computing apparatus image data associated with the cargo container and conveying information related to contents of the cargo container, said image data being derived by subjecting the cargo container to penetrating radiation; b) receiving at said computing apparatus a list of objects conveying objects expected to be present in the cargo container; c) using the processor of said computing apparatus; i. obtaining a group of target images based at least in part on the list of objects, the target images in said group corresponding to respective objects in the list of objects; and ii. processing the image data associated with the cargo container in combination with the group of target images to derive mismatch information data, said mismatch information data conveying at least one distinction between the list of objects and the information related to the contents of the cargo container conveyed by the image data; d) releasing at an output of said computing apparatus the mismatch information data.