Mammography tomosynthesis apparatus with a compression plate having a recess therein
View Patent ↗A tomosynthesis apparatus for mammography has an x-ray source for emission of x-ray beams from different directions directed toward a detector, and a compression plate and a support plate arranged in the beam path between the x-ray source and the detector. A breast to be examined is positioned and compressed between the compression plate and the support plate. The compression plate exhibits a concave recess open in the direction of the support plate on the side of the compression plate facing toward the support plate.
1. A tomosynthesis mammography apparatus comprising;
an x-ray source that emits an x-ray beam;
a radiation detector on which said x-ray beam is incident;
a compression plate and a support plate located between said x-ray source and said radiation detector in a beam path of said x-ray beam, said compression plate and said support plate being configured to retain and compress a breast therebetween;
said x-ray source being configured to emit said x-ray beam to irradiate the breast between the compression plate and the support plate from a plurality of different directions, and said radiation detector being configured to detect x-rays in said x-ray beam, attenuated by the breast between said compression plate and support plate, from each of said different directions to generate a plurality of projection images of the breast;
said compression plate having a side facing said support plate, which is in contact with said breast, and having a concave recess in said side that accommodates the breast therein; and
a processor supplied with said projection images configured to execute a reconstruction algorithm to generate a 3D tomosynthesis image of the breast from said projection images.
2. A tomosynthesis apparatus as claimed in claim 1 wherein said compression plate is dimensionally stable.
3. A tomosynthesis apparatus as claimed in claim 1 wherein said compression plate is reversibly deformable between an unloaded state wherein the breast is not compressed and a loaded state wherein the breast is compressed, and wherein said compression plate exhibits said concave recess both in said unloaded state and in said loaded state.
4. A tomosynthesis apparatus as claimed in claim 1 wherein said x-ray source irradiates a volume of the breast with said x-ray beam in each of said projection images, the respective volumes in said projection images, collectively and in combination, defining a tomosynthetic examination volume, and wherein said recess of said compression plate is situated entirely within said tomosynthetic examination volume.
5. A tomosynthesis apparatus as claimed in claim 1 wherein said concave recess of said compression plate has a surface contour facing said support plate conforming to at least a portion of a contour of said tomosynthetic examination volume.
6. A tomosynthesis apparatus as claimed in claim 5 wherein concave recess of said compression plate has a longitudinal extent in a direction proceeding perpendicularly from a chest wall plane of an examination subject whose breast is being irradiated.
7. A tomosynthesis apparatus as claimed in claim 6 wherein said recess of said compression plate has a concave inner contour as seen in a slice plane perpendicular to said longitudinal extent.
8. A tomosynthesis apparatus as claimed in claim 7 wherein an inner side of the concave recess of said compression plate has a rounded curve as seen in said slice plane perpendicular to said longitudinal extent.
9. A tomosynthesis apparatus as claimed in claim 8 wherein said inner side of said concave recess has a shape substantially corresponding to a segment of a cylinder surface.
10. A tomosynthesis apparatus as claimed in claim 9 wherein said inner side of said concave recess has a shape corresponding to a segment of a surface of a cylinder selected from the group consisting of a circular cylinder, a parabolic cylinder, and an elliptical cylinder.
11. A tomosynthesis apparatus as claimed in claim 6 wherein said concave recess has an inner side having a trapezoidal shape as seen in a slice plane perpendicular to said longitudinal extent.
12. A tomosynthesis apparatus as claimed in claim 6 wherein said concave recess of said compression plate has a shape corresponding to a channel in a direction along said longitudinal extent.
13. A tomosynthesis apparatus as claimed in claim 1 wherein said compression plate has an edge oriented substantially perpendicularly to said support plate.
14. A tomosynthesis apparatus as claimed in claim 1 wherein said compression plate is composed of non-metallic components.
15. A tomosynthesis apparatus as claimed in claim 1 wherein said compression plate is comprised of a plastic material.