Wide angle automatic exposure control in tomosynthesis

A method of performing an automatic exposure control (AEC) operation using a tomosynthesis system, the method comprising:

• acquiring a scout image of a patient's breast at a first projection angle by emitting a scout x-ray dosage towards the patient's breast with the tomosynthesis system, the scout image including a plurality of pixels, wherein each of the plurality of pixels is associated with a detector count value from among a plurality of detector count values;
• identifying a first region on the scout image as corresponding to a densest portion of the patient's breast;
• calculating an average detector count value by averaging the one or more detector count values corresponding to the one or more pixels within the first region;
• identifying a second region on a first reference image associated with the first projection angle, wherein the second region corresponds to a location on the first reference image that matches a location of the first region on the scout image;
• obtaining one or more reference detector count values associated with one or more reference pixels within the second region of the first reference image;
• calculating an average reference detector count value by averaging the one or more reference detector count values;
• based on a ratio between the average reference detector count value and the average detector count value, calculating an AEC calibrated dosage to use in a tomosynthesis scan;
• and
• setting a radiation dosage for a tomosynthesis sweep at a plurality of projection angles on the patient's breast to the AEC calibrated dosage.

A method of performing a calibration operation associated with an automatic exposure control (AEC) operation using a tomosynthesis system, the method comprising:

• acquiring a plurality of reference images of a phantom at a plurality of projection angles, wherein each of the plurality of reference images include a plurality of reference image pixels;
• generating a plurality of reference image detector count maps corresponding to each of the plurality of reference images by compiling a plurality of reference image pixels and corresponding reference image detector count values associated for each of the plurality of reference images;
• storing the plurality of reference image detector count maps;
• acquiring a scout image of a patient's breast at the first projection angle by emitting a scout x-ray dosage towards the patient's breast with the tomosynthesis system, the scout image including a plurality of pixels, wherein each of the plurality of pixels is associated with a detector count value from among a plurality of detector count values;
• identifying a first region on the scout image as corresponding to a densest portion of the patient's breast;
• calculating an average detector count value by averaging the one or more detector count values corresponding to the one or more pixels within the first region;
• identifying a second region on a first reference image associated with a first projection angle, wherein the second region corresponds to a location on the first reference image that matches a location of the first region on the scout image and the first projection angle is one of the plurality of projection angles and the first reference image is one of the plurality of reference images;
• obtaining one or more reference detector count values associated with one or more reference pixels within the second region of the first reference image;
• calculating an average reference detector count value by averaging the one or more reference detector count values;
• based on a ratio between the average reference detector count value and the average detector count value, calculating an AEC calibrated dosage to use in a tomosynthesis scan;
• and
• setting a radiation dosage for a tomosynthesis sweep at a plurality of projection angles on the patient's breast to the AEC calibrated dosage.