A computed tomography (CT) imaging system (100) and method, wherein the system includes an x-ray source (114) that is operable to emit a beam (215) of x-rays (116) from a focal spot and move a spot position of the focal spot. The system also includes a detector assembly that is configured to detect the x-rays (116) attenuated by the object. At least one processing unit (136) is configured to execute programmed instructions stored in memory. The at least one processing unit (136) is configured to direct the x-ray source (114) to emit different beams (215) of the x-rays (116) at different energy levels and to receive data from the detector assembly that are representative of detection of the x-rays (116) emitted at the different energy levels. The at least one processing unit (136) is also configured to direct the x-ray source (114) to move the focal spot such that the focal spot is at different spot positions while the different beams (215) are emitted.
