1. An X-ray CT scanner for imaging an object, said X-ray CT scanner comprising: an X-ray emitter configured to emit X-ray beams towards the object; a detector array positioned opposite said X-ray emitter and comprising a plurality of detector elements; a precollimator positioned between said X-ray emitter and the object, said precollimator configured to: prevent, using at least one blocking portion, the emitted X-ray beams from being directly incident on a first subset of said plurality of detector elements; and allow the emitted X-ray beams to be directly incident on a second subset of said plurality of detector elements; and a processing device communicatively coupled to said detector array, said processing device configured to: determine a signature of the object based on a first set of data acquired using said first subset of said plurality of detector elements; and tomographically reconstruct an image of the object based on a second set of data acquired using said second subset of said plurality of detector elements.