1. An x-ray scanning system comprising: (a) a field-emission x-ray source comprising: (i) a field-emission cathode comprising a plurality of individually-controllable pixels configured to emit multiplexed electron beams; (ii) an anode positioned in an opposing relationship with the cathode and comprising a plurality of focal spots positioned to receive electron beams emitted by the pixels and transmit x-ray beams toward an object to be scanned from a plurality of different locations; (b) an x-ray detector operable to detect x-ray intensities of each of the x-ray beams; and (c) a control system configured to control the x-ray source and the x-ray detector, to identify the x-ray intensities of each of the x-ray beams, and to demultiplex the identified x-ray intensities for generating imaging data.