Matching geometry generation and display of mammograms and tomosynthesis images
View Patent ↗A method and a system for using tomosynthesis projection images of a patient's breast to reconstruct slice tomosynthesis images such that anatomical structures that appear superimposed in a mammogram are at conforming locations in the reconstructed images.
1. A method comprising:
acquiring several 2D x-ray tomosynthesis projection images Tp of a patient's breast taken at different angles of an imaging x-ray beam relative to the breast;
computer-processing the projection images Tp into reconstructed slice images Tr representing respective 3D slices of the breast;
each of said slice images Tr comprising respective pixel values of a respective array of pixels;
wherein the pixels of at least one of said slice images Tr represent respective slice volumes that differ in size from those represented by the pixels of at least another one of said slice images Tr at least in planes to which said slices conform; and
selectively displaying said slice images Tr on a computer display unit.
2. A method as in claim 1 where the slice volumes represented by pixels of the respective slice images Tr change progressively in size with distance of the slices from a source of said imaging x-ray beam.
3. A method as in claim 2 in which said imaging x-ray beam is a divergent x-ray beam imaging the breast at an image receptor, and said change in size causes objects in the breast that are along respective rays of said beam to appear at locations in said slice images Tr matching locations in which said object would have appeared in a mammogram of the breast.
4. A method as in claim 3 in which said computer-processing into slice images Tr comprises using a cone beam reconstruction process directly generating said slice images Tr.
5. A method as in claim 3 in which said computer-processing into slice images Tr comprises indirectly generating said slice images Tr by first using a reconstruction process to obtain initial slice images Tr(i) in a first coordinate system and further computer-processing said initial slice images Tr(i) to map them into a second coordinate system that differs from the first coordinate system.
6. A method as in claim 1 further comprising acquiring a mammogram of the breast, wherein objects in the breast appear in said slice images Tr at locations matching those in which the objects appear in the mammogram.
7. A method as in claim 1 in which said projection images Tp are acquired using an x-ray image receptor having an imaging plane, and said slice images Tr conform to planes selectively angled relative to said imaging plane.
8. A method as in claim 1 in which said projection images Tp are acquired using an x-ray image receptor having an imaging plane, wherein said slices conform to planes parallel to said imaging plane.
9. A method comprising:
acquiring several 2D x-ray tomosynthesis projection images Tp of a patient's breast taken at different angles of an imaging x-ray beam relative to the breast;
computer-processing the projection images Tp into reconstructed slice images Tr representing respective 3D slices of the breast;
each of said slice images Tr comprising respective pixel values of a respective array of pixels;
wherein the pixels of at least one of said slice images Tr have different pixel spacing from the pixels of at least another one of said images Tr at least in planes to which the slices conform; and
selectively displaying said slice images Tr on a computer display unit.
10. An x-ray system comprising:
a data acquisition unit comprising an x-ray source selectively emitting x-rays and an x-ray receptor acquiring several projection tomosynthesis images Tp of a patient's breast taken at different angles of the x-rays relative to the breast;
a computer-implemented image reconstruction unit receiving the projection images Tp and reconstructing them into slice images Tr representing respective slices of the breast;
each of said slice images Tr comprising respective pixel values representing a respective array of pixels;
wherein the pixels of at least one of said slice images Tr represent voxels of the breast that differ in size from those represented by pixels in at least another one of said images Tr at least in planes to which the respective slices conform; and
a display unit selectively displaying one or more of the slice images Tr, said display unit comprising a user interface controlling the display of said images Tr.
11. A system as in claim 10 wherein said image reconstruction unit comprises a computer-implemented cone beam reconstruction algorithm directly generating the slice images Tr.
12. A system as in claim 10 wherein said image reconstruction unit comprises an algorithm indirectly generating said slice images Tr by first generating initial slice images Tr(i) having pixels representing voxels that are the same in size and then mapping said initial slice images Tr(i) into said slice images Tr.
13. A system as in claim 10 in which said data acquisition unit further acquires a mammogram of the breast, and objects in said slice images Tr images appear at locations matching the locations in which the objects appear in the mammogram.