Dynamic control of x-ray exposure using focal spot translation

A system for acquiring x-ray data for a computed tomography (CT) image of a subject, the system comprising:

• an x-ray source comprising an actuator system configured to energize one of a plurality of focal spot positions;
• a grid assembly positioned in front of the x-ray source and comprising a plurality of grids, wherein each grid comprises a plurality of attenuating objects;
• a processor device coupled to the x-ray source and programmed to:
• receive a set of illumination field data including an illumination field produced by each of the plurality of focal spot positions of the x-ray source;
• select at least one sequence of at least two illumination fields from the set of illumination field data based on at least one subject-specific parameter;
• and
• assign an illumination field from the selected at least one sequence of at least two illumination fields to each gantry rotation angle in a plurality of gantry rotation angles;
• and
• a detector array configured to receive x-ray data from the subject for each gantry rotation angle in the plurality of gantry rotation angles, the x-ray data for each gantry rotation angle based on the illumination field assigned to the gantry rotation angle and produced by an energized focal spot position associated with the assigned illumination field, wherein the x-ray data includes a number of photons received by the detector array.

A system for acquiring x-ray data for a computed tomography (CT) image of a subject, the system comprising:

• an x-ray source comprising an actuator system configured to energize one of a plurality of focal spot positions;
• a slot collimator positioned in front of the x-ray source and comprising an opening having a width;
• a processor device coupled to the x-ray source and programmed to:
• receive a set of illumination field data including an illumination field produced by each of the plurality of focal spot positions of the x-ray source;
• select at least one sequence of at least two illumination fields from the illumination field data based on at least one subject-specific parameter;
• and
• assign an illumination field from the selected at least one sequence of at least two illumination fields to each gantry rotation angle in a plurality of gantry rotation angles;
• and
• a detector array configured to receive x-ray data from the subject for each gantry rotation angle in the plurality of gantry rotation angles, the x-ray data for each gantry rotation angle based on the illumination field assigned to the gantry rotation angle and produced by an energized focal spot position associated with the assigned illumination field, wherein the x-ray data includes a number of photons received by the detector array.