# US 11,076,820 B2 · Tomosynthesis with shifting focal spot x-ray system using an addressable array > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,076,820 B2 - Document ID: US11076820B2 - Status: Granted - Kind: B2 - Application number: 16/095,416 - Filed: 2017-04-21 - Published: 2020-11-12 - Granted: 2021-08-03 - Earliest claimed: 2016-04-22 - Assignees: Hologic, Inc. - Applicants: Hologic, Inc. - Inventors: Andrew P. Smith; John Laviola - Web page: https://patentgrep.com/patent/US11076820B2 ## CPC - A61B 6/4007: {characterised by using a plurality of source units} - A61B 6/405: {Source units specially adapted to modify characteristics of the beam during the data acquisition process (A61B6/4021, A61B6/4035 take precedence)} - A61B 6/025: {Tomosynthesis} - A61B 6/0414: {with compression means} - A61B 6/4021: {involving movement of the focal spot} - A61B 6/4441: {the rigid structure being a C-arm or U-arm} - A61B 6/4476: {related to motor-assisted motion of the source unit} - A61B 6/502: {for diagnosis of breast, i.e. mammography} - A61B 6/542: {involving control of exposure} - H01J 35/065: {Field emission, photo emission or secondary emission cathodes} - H01J 35/10: Rotary anodes; Arrangements for rotating anodes; Cooling rotary anodes - H01J 2201/30469: Carbon nanotubes (CNTs) - H01J 2235/068: Multi-cathode assembly - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract A tomosynthesis system has an x-ray source with an addressable array of electron emitting sections on the cathode. The x-ray source moves rotationally about an imaging target, such as a breast. During the rotation, x-rays are emitting from the x-ray source while the x-ray source continues to move. During the emission of x-rays, different subsets of electron-emitting sections of the addressable array are activated to compensate for movement of the x-ray source. By activating the different subsets of electron-emitting sections, an effective focal spot of the x-ray position appears to retain the same shape, size, and position from the perspective of the imaging target, despite movement of the x-ray source itself. ## Claims ### Claim 1 A system for radiographic imaging, the system comprising: a rotating arm configured to rotate relative to a target tissue; a radiation source attached to the rotating arm, the radiation source comprising a cathode and an anode, wherein the cathode comprises an array of electron-emitting sections; and a controller operatively connected to the cathode, the controller configured to activate a first subset of the array of electron-emitting sections when the radiation source is located in a first position relative to the target, and activate a second subset of the array of electron-emitting sections when the radiation source is located in a second position relative to the target, wherein the second subset of electron-emitting sections are selected to compensate for movement from the first position to the second position in order to make a focal spot appear stationary from the perspective of the target. ### Claim 2 (depends on 1) The system of claim 1, wherein the rotating arm moves in a first direction and the second subset of the array of electron-emitting sections includes electron-emitting sections spaced apart from the first subset of the array of electron-emitting sections in a direction opposite the first direction. ### Claim 3 (depends on 1) The system of claim 1, wherein each electron-emitting section includes at least one field emission emitter. ### Claim 4 (depends on 3) The system of claim 3, wherein each electron-emitting section includes at least one carbon-nanotube emitter. ### Claim 5 (depends on 1) The system of claim 1, wherein the first subset of electron-emitting sections and the second subset of electron-emitting sections are individually addressable by the controller. ### Claim 6 (depends on 1) The system of claim 1, wherein the array comprises multiple rows of electron-emitting sections, wherein each row is individually addressable by the controller. ### Claim 7 (depends on 6) The system of claim 6, wherein each row includes a gate portion and an emitter portion, the gate portion connected to a transistor connected to the controller. ### Claim 8 (depends on 1) The system of claim 1, wherein each electron-emitting section is individually addressable by the controller. ### Claim 9 (depends on 8) The system of claim 8, wherein each electron-emitting section includes a gate portion and an emitter portion, the gate portion connected to a transistor connected to the controller. ### Claim 10 (depends on 1) The system of claim 1, wherein the radiation source is configured to emit radiation to a single location on the target as the radiation source moves from the first position and the second position. ### Claim 11 A method for radiographic imaging, the method comprising: moving a radiation source relative to a target from a first position to a second position while emitting radiation from the radiation source to a location of the target, the radiation source including an array of electron-emitting sections; while moving the radiation source from the first position to the second position, activating a first subset of the electron-emitting sections at the first position and activating a second subset of electron-emitting sections at the second position, wherein the second subset of electron-emitting sections are selected to compensate for movement from the first position to the second position in order to make a focal spot appear stationary from the perspective of the target; and detecting the emitted radiation. ### Claim 12 (depends on 11) The method of claim 11, wherein the second subset of the array of electron-emitting sections includes electron-emitting sections from the first subset of the array of electron-emitting sections. ### Claim 13 (depends on 11) The method of claim 11, wherein each electron-emitting section includes at least one field emission emitter. ### Claim 14 (depends on 11) The method of claim 11, wherein each electron-emitting section includes at least one carbon-nanotube emitter. ### Claim 15 (depends on 11) The method of claim 11, wherein the array comprises multiple rows of electron-emitting sections, wherein each row is individually addressable. ### Claim 16 (depends on 11) The method of claim 11, wherein each electron-emitting section is individually addressable. ### Claim 17 A method for radiographic imaging, the method comprising: activating a first subset of electron-emitting sections of a cathode of a radiation source; directing radiation emitted from the radiation source to a location on a target; moving the radiation source relative to the target; and while moving the radiation source, deactivating the first subset of the electron-emitting sections and activating a second subset of electron-emitting sections to maintain the location on the target. ### Claim 18 (depends on 17) The method of claim 17, wherein the second subset of electron-emitting sections includes electron-emitting sections from the first subset of electron-emitting sections. ### Claim 19 (depends on 17) The method of claim 17, wherein the cathode comprises multiple rows of electron-emitting sections, and each row is individually addressable. ### Claim 20 (depends on 17) The method of claim 17, wherein each electron-emitting section comprises a single emitter that is individually addressable. ### Claim 21 A radiation source, for use in radiographic imaging, comprising a cathode including a three-dimensional addressable array comprising a plurality of cathode plates having a plurality of addressable electron-emitting sections, wherein electron density emitted from the cathode is greater than an electron density that would be produced from the cathode plates if the cathode plates were arranged in a two-dimensional configuration. ### Claim 22 (depends on 21) The radiation source of claim 21, wherein the three-dimensional addressable array is a v-shaped three-dimensional array. ### Claim 23 (depends on 21) The radiation source of claim 21, wherein the three-dimensional addressable array is a pyramidal three-dimensional array. ### Claim 24 (depends on 23) The radiation source of claim 23, wherein the pyramidal three-dimensional array includes at least four cathode plates. ### Claim 25 (depends on 24) The radiation source of claim 24, where a first pair of the cathode plates are configured to linearly move a focal spot of the electrons emitted from the cathode and a second pair of cathode plates are configured to direct electrons emitted from the first pair of the cathode plates.