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US 8,275,090 B2Granted
Multi-mode tomosynthesis/mammography gain calibration and image correction using gain map information from selected projection angles
AssigneeHologic, Inc.
InventorsBaorui Ren, Andrew P. Smith, Zhenxue Jing, Jay Stein
Life of this patent
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Abstract
A multi-mode tomosynthesis/mammography system and method in which a mammography gain map is used to gain correct mammographic images of a patient's breast but enhanced gain maps for respective projection angled are used to correct tomosynthesis images acquired with the same system.
Claims32
A multi-mode breast tomosynthesis/mammography system comprising:
- an image acquisition unit comprising an x-ray source, a breast immobilizer, and an x-ray image receptor, said unit acquiring projection x-ray images of an object at selected projection angles;
- a scan motion controller selectively operating said system:
- in a tomosynthesis mode, in which at least one of the x-ray source and the x-ray image receptor moves relative to the breast immobilizer while a patient's breast remains immobilized therein and take tomosynthesis projection images at respective angles or angle ranges of the source relative to the breast immobilizer;
- or
- in a mammography mode, in which the x-ray source, the breast immobilizer and the x-ray image receptor maintain a fixed rotational relationship to move together under the control of the scan motion controller and take at least one mammography image;
- an initial gain map generator configured to receive x-ray projection images taken with said image acquisition unit of a phantom at a multiplicity of first projection angles while said system is operating in said tomosynthesis mode, said initial gain map generator being further configured to process the projection images of the phantom received thereby and generate therefrom an initial gain map for each of said first projection angles;
- an enhanced gain map generator configured to receive said initial gain maps, said enhanced map generator being further configured to process the initial gain maps received thereby and generate therefrom at least one enhanced gain map;
- a mammography gain map generator configured to receive at least one mammographic image of a phantom while the system is operating in said mammography mode and to generate a mammography gain map therefrom;
- an image generator configured to receive said enhanced gain maps and tomosynthesis projection x-ray images of a patient's breast taken with said image acquisition unit at a multiplicity of second projection angles while the system is operating in said tomosynthesis mode, said image generator being further configured to gain-correct said tomosynthesis breast images with said at least one enhanced gain maps to thereby generate gain-corrected tomosynthesis breast images;
- said image generator being further configured
- said image generator being further configured to receive at least one mammography image generated while the system is operating in said mammography mode and to gain correct said mammography image with said mammography gain map to thereby generate a gain-corrected mammography image;
- and
- selectively displaying at least some of said tomosynthesis projection images, said gain-corrected tomosynthesis breast images and said gain-corrected mammography image.
10 more elements
A breast x-ray imaging method comprising:
- obtaining tomosynthesis projection x-ray images T(p,n) of a phantom, where the index p designates a respective one of a first multiplicity of P first projection angles of an x-ray beam relative to the phantom, p=1, 2, 3, . . . , P, the index n designates the number of projection images taken at a given one of the first projection angles, and n≧2;
- obtaining enhanced gain maps EG(p′), where the index p′ designates a respective one of a second multiplicity of P′ second projection angles of an x-ray beam relative to a patient's breast and p′=1, 2, 3, . . . , P′, said maps EG(p′) having been generated in a computer-implemented process combining parameters derived from said images T(p,n);
- storing the enhanced gain maps EG(p′) in a table;
- obtaining tomosynthesis x-ray images T′(p′) of a patient's breast acquired at said second projection angles;
- gain-correcting the tomosynthesis x-ray images T′(p′) of the patient's breast using the stored enhanced gain maps EG(p′) in a computer-implemented process to thereby produce gain-corrected breast images;
- and
- further computer-processing said gain-corrected breast images to generate therefrom display breast images, and displaying said display breast images derived through said further computer-processing.
4 more elements
A breast x-ray imaging method comprising:
- obtaining tomosynthesis projection x-ray images of a phantom at each of a multiplicity of first projection angles of an x-ray beam relative to the phantom;
- obtaining respective initial gain maps for said first projection angles wherein said initial gain maps are related to differences between expected and actual characteristics of pixel values in said projection x-ray images of the phantom;
- obtaining tomosynthesis x-ray images of a patient's breast acquired for each of a multiplicity of second projection angles, wherein the second projection angles differ in number or in angle values from said first projection angles;
- obtaining respective enhanced gain maps for said second projection angles, said enhanced gain maps having been generated by computer-processing parameters derived from said initial gain maps;
- storing the enhanced gain maps in a table;
- gain-correcting said tomosynthesis x-ray images of the patient's breast using said stored enhanced gain maps;
- further computer-processing said gain-corrected breast images to generate processed breast images;
- and
- displaying said processed breast images resulting from said further computer-processing.
6 more elements
A method of operating a tomosynthesis system comprising:
- acquring tomosynthesis projection x-ray images of a phantom, where at least one phantom projection image is acquired for each of a multiplicity of different first projection angles relative to the phantom;
- generating initial tomosynthesis gain maps for said first projection angles using said tomosynthsis projection images of the phantom;
- forming at least one enhanced tomosynthesis gain map by combining at least some of the initial tomosynthsis gain maps;
- operating the system to acquire tomosynthesis x-ray images of a patient's breast at a multiplicity of second projection angles;
- and
- selectively displaying the resulting gain-corrected mammogram images and/or tomosynthesis images.
3 more elements
Dependencies are inferred from the claim text.