3D-beam modulation filter for equalizing dose and image quality in breast CT

A computed tomography (CT) scanner system, comprising:

• an x-ray production system including an x-ray source configured to emit x-rays;
• an x-ray detector system constructed and arranged to receive the x-rays emitted by the x-ray source;
• a filter positioning system configured to select a 3D-beam modulation filter among a plurality of 3D-beam modulation filters each corresponding to a different breast volume class in a plurality of breast volume classes, said selected 3D-beam modulation filter corresponding to a breast volume class assigned to a body part to be imaged, said assigning based on at least one of a shape and a size of the body part, and further configured to position the selected 3D-beam modulation filter between the x-ray source and the x-ray detector system,
• wherein each 3D-beam modulation filter has a three-dimensional shape corresponding to at least one of a size and a three-dimensional shape of one of said breast volume classes so as to equalize intensities of individual x-rays within an x-ray beam after said x-ray beam passes through the body part, and
• wherein said plurality of breast volume classes are defined from a plurality of CT data sets of a plurality of persons, each breast volume class corresponding to a different range of breast volume percentile groups;
• and
• a gantry assembly system including a table for receiving the body part.

A cone-beam breast computed tomography (CT) system, comprising:

• a table arranged to support a person to lie prone with the person's breast extending through an aperture defined by the table;
• a plurality of breast immobilizers, each corresponding to a different breast volume class out of a corresponding plurality of breast volume classes, each breast immobilizer structured to be connectable to and disconnectable from said table at said aperture to immobilize said person's breast when it extends through said aperture;
• a gantry disposed proximate to said table;
• a cone-beam x-ray source attached to said gantry and positioned to be able to irradiate said person's breast with a cone beam of x-rays;
• a plurality of modulation filters, each corresponding to one of said plurality of breast volume classes, and each adapted to be connected to and disconnected from said gantry at a position between said cone-beam x-ray source and said person's breast;
• and
• a flat-panel detector attached to said gantry and positioned to be able to receive at least a portion of said cone beam of x-rays after passing through said person's breast,
• wherein said gantry is rotatable about an axis that intercepts said person's breast such that said cone-beam x-ray source and said flat-panel detector rotate with said gantry in unison, and
• wherein said plurality of breast volume classes are defined from a plurality of CT data sets of a plurality of persons, each breast volume class corresponding to a different range of breast volume percentile groups, and
• wherein at least one modulation filter of said plurality of modulation filters is a 3D-beam modulation filter that has a three-dimensional shape corresponding to at least one of a size and a three-dimensional shape of one of said breast volume classes so as to equalize intensities of individual x-rays within an x-ray beam after said x-ray beam passes through said person's breast.

An accessory kit for a cone-beam breast computed tomography (CT) system, comprising:

• a plurality of breast immobilizers, each corresponding to a different breast volume class out of a corresponding plurality of breast volume classes, and each being structured to be connectable to and disconnectable from a table of said cone-beam breast CT system at an aperture defined by said table;
• and
• a plurality of modulation filters, each corresponding to a different breast volume class out of the corresponding plurality of breast volume classes, and each adapted to be connected to and disconnected from a gantry at a position between a cone-beam x-ray source and said person's breast,
• wherein the plurality of breast volume classes are defined from a plurality of CT data sets of a plurality of persons, each breast volume class corresponding to a different range of breast volume percentile groups,
• wherein each breast immobilizer is configured to immobilize a person's breast when it extends through said aperture, and
• wherein at least one modulation filter of said plurality of modulation filters is a 3D-beam modulation filter that has a three-dimensional shape corresponding to at least one of a size and a three-dimensional shape of one of said breast volume classes so as to equalize intensities of individual x-rays within an x-ray beam after said x-ray beam passes through said person's breast.

An accessory kit for a cone-beam breast computed tomography (CT) system, comprising:

• a plurality of modulation filters, each corresponding to a different breast volume class out of a corresponding plurality of breast volume classes, and each adapted to be connected to and disconnected from a gantry at a position between a cone-beam x-ray source and a person's breast,
• wherein the plurality of breast volume classes are defined from a plurality of CT data sets of a plurality of persons, each breast volume class corresponding to a different range of breast volume percentile groups,
• wherein each said modulation filter compensates for different x-ray path lengths through different portions of said person's breast of the corresponding breast volume class to reduce a total amount of x-ray dose,
• wherein each said modulation filter, when connected to said gantry, is rotatable with said gantry in unison with said cone-beam x-ray source and a flat-panel detector, and
• wherein at least one modulation filter of said plurality of modulation filters is a 3D-beam modulation filter that has a three-dimensional shape corresponding to at least one of a size and a three-dimensional shape of one of said breast volume classes so as to equalize intensities of individual x-rays within an x-ray beam after said x-ray beam passes through said person's breast.