# US 9,517,036 B2 · Radiation imaging using very slow rotational technique > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,517,036 B2 - Document ID: US9517036B2 - Status: Granted - Kind: B2 - Application number: 13/589,514 - Filed: 2012-08-20 - Published: 2014-02-20 - Granted: 2016-12-13 - Earliest claimed: 2012-08-20 - Assignees: Varian Medical Systems, Inc. - Applicants: Hassan Mostafavi - Inventors: Hassan Mostafavi - Web page: https://patentgrep.com/patent/US9517036B2 ## CPC - A61B 6/035: {Mechanical aspects of CT} - A61B 6/025: {Tomosynthesis} - A61B 6/486: {involving generating temporal series of image data} - A61B 6/5288: {involving retrospective matching to a physiological signal} - A61B 6/584: {determining position of components of the apparatus or device using images of the phantom} - A61B 6/032: {Transmission computed tomography [CT]} - A61B 6/4441: {the rigid structure being a C-arm or U-arm} - A61B 6/5235: {combining images from the same or different ionising radiation imaging techniques, e.g. PET and CT} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract An imaging system includes a radiation source, a positioner configured to rotate the radiation source along an arc path at a rate less than 0.5 degree/sec, an imager in operative position relative to the radiation source, wherein the radiation source and the imager are configured to obtain a plurality of images while the radiation source is at different positions along the arc path, and a processor configured to determine a digital tomosynthesis image using a subset of the plurality of images. An imaging method includes generating a control signal to control a positioner to rotate a radiation source through an arc path at a rate less than 0.5 degree/sec, obtaining a plurality of images that are generated using radiation from the radiation source while the radiation source is at different positions along the arc path, and determining a digital tomosynthesis image using a subset of the plurality of images. ## Claims ### Claim 1 An imaging system, comprising: a radiation source; a positioner configured to rotate the radiation source along an arc path at a rate that is equal to or less than Rmax, Rmax being calculated from α and T using a processing unit, and being equal to α/T, wherein the rate is a speed of rotation of the radiation source when the radiation source is rotating; an imager in operative position relative to the radiation source, wherein the radiation source and the imager are configured to obtain a plurality of images while the radiation source is at different positions along the arc path; and a processor configured to determine a digital tomosynthesis image using a subset of the plurality of images; where α is an angular spacing between a subset of the images that belongs to a same bin, and T is a period of a physiological motion, wherein at least two images in the subset of the images belonging to the same bin correspond with two different respective positions of the radiation source. ### Claim 2 (depends on 1) The imaging system of claim 1, wherein the rate is less than α/T, and the rate has a value that is a function of the period T of physiological motion. ### Claim 3 (depends on 1) The imaging system of claim 1, wherein the images are for a target undergoing respiratory motion, and the rate at which the positioner is configured to move the radiation source is less than 0.4 degree/sec. ### Claim 4 (depends on 1) The imaging system of claim 1, wherein the images are for a target undergoing respiratory motion, and the rate at which the positioner is configured to move the radiation source is less than 0.3 degree/sec. ### Claim 5 (depends on 1) The imaging system of claim 1, wherein the images are for a target undergoing cardiac motion, and the rate at which the positioner is configured to move the radiation source is less than 3.3 degree/sec. ### Claim 6 (depends on 1) The imaging system of claim 1, wherein the images are for a target undergoing cardiac motion, and the rate at which the positioner is configured to move the radiation source is less than 2 degree/sec. ### Claim 7 (depends on 1) The imaging system of claim 1, wherein the arc path has a corresponding arc angle that is anywhere from 2 degrees to 10 degrees. ### Claim 8 (depends on 1) The imaging system of claim 1, wherein the radiation source and the imager are configured to obtain the plurality of images at a frame rate that is equal to or higher than NB/T, wherein NB is a prescribed number of bins. ### Claim 9 (depends on 1) The imaging system of claim 1, wherein the plurality of images comprises at least 60 images that are obtained while the radiation source is at the different positions along the arc path, and the arc path has a corresponding arc angle that is less than 10degrees. ### Claim 10 (depends on 1) The imaging system of claim 1, wherein the radiation source and the imager are configured to obtain the plurality of images at a frame rate that is at least 2 fps. ### Claim 11 (depends on 1) The image system of claim 1, wherein the processor is configured to display at least a part of the digital tomosynthesis image over one of the plurality of images. ### Claim 12 (depends on 1) The image system of claim 1, wherein the radiation source and the imager are configured to obtain an additional plurality of images, and the processor is further configured to update the digital tomosynthesis image using the subset of the plurality of images and at least one of the additional plurality of images. ### Claim 13 (depends on 1) The image system of claim 1, wherein the plurality of images comprises different image sets, each of the image sets comprises images that correspond with a phase or a phase range of a physiological cycle, and wherein the processor is configured to determine the digital tomosynthesis image using one of the image sets. ### Claim 14 (depends on 13) The image system of claim 13, wherein the images in each of the image sets have a substantially uniform angular spacing. ### Claim 15 (depends on 1) The image system of claim 1, wherein the processor is further configured to obtain a portion of a volumetric image that corresponds with a plane of the tomosynthesis image, and compare the portion of the volumetric image with the tomosynthesis image. ### Claim 16 (depends on 1) The image system of claim 1, wherein the processor is further configured to: determine a first digital tomosynthesis image and a second digital tomosynthesis images using at least some of the plurality of images obtained while the radiation source is at the different positions along the arc path; and outputting the first and second digital tomosynthesis images for display on a screen in a form of a video. ### Claim 17 (depends on 1) The image system of claim 1, wherein the radiation source is coupled to a C-arm. ### Claim 18 (depends on 1) The image system of claim 1, wherein the imager is coupled to a floor. ### Claim 19 (depends on 1) The image system of claim 1, wherein the positioner is configured to rotate the radiation source in a single rotational direction. ### Claim 20 (depends on 1) The image system of claim 1, wherein the positioner is configured to rotate the radiation source in two opposite rotational directions. ### Claim 21 (depends on 1) The image system of claim 1, wherein the arc path is rectilinear with a corresponding infinite arc radius. ### Claim 22 An imaging method, comprising: generating a control signal to control a positioner to rotate a radiation source through an arc path at a rate that is equal to or less than Rmax, Rmax being calculated from α and T using a processing unit, and being equal to α/T, wherein the rate is a speed of rotation of the radiation source when the radiation source is rotating; and obtaining a plurality of images that are generated using radiation from the radiation source while the radiation source is at different positions along the arc path; and determining a digital tomosynthesis image using a subset of the plurality of images; where α is an angular spacing between a subset of the images that belongs to a same bin, and T is a period of a physiological motion, wherein at least two images in the subset of the images belonging to the same bin correspond with two different respective positions of the radiation source. ### Claim 23 (depends on 22) The method of claim 22, further comprising obtaining: the period T of physiological motion; and determining the rate as a function of the period T. ### Claim 24 (depends on 22) The method of claim 22, wherein the images are for a target undergoing respiratory motion, and the rate is less than 0.4 degree/sec. ### Claim 25 (depends on 22) The method of claim 22, wherein the images are for a target undergoing respiratory motion, and the rate is less than 0.3 degree/sec. ### Claim 26 (depends on 22) The method of claim 22, wherein the images are for a target undergoing cardiac motion, and the rate is less than 3.3 degree/sec. ### Claim 27 (depends on 22) The method of claim 22, wherein the images are for a target undergoing cardiac motion, and the rate is less than 2 degree/sec. ### Claim 28 (depends on 22) The method of claim 22, wherein the arc path has an arc angle that is anywhere from 2 degrees to 10 degrees. ### Claim 29 (depends on 22) The method of claim 22, wherein the images are generated at a frame rate that is equal to or higher than NB/T, wherein NB is a prescribed number of bins. ### Claim 30 (depends on 22) The method of claim 22, wherein the images comprises at least 60 images that are obtained while the radiation source is at the different positions along the arc path, and the arc path has a corresponding arc angle that is less than 10 degrees. ### Claim 31 (depends on 22) The method of claim 22, wherein the images are generated at a frame rate that is at least 2 fps. ### Claim 32 (depends on 22) The method of claim 22, further comprising displaying at least a part of the digital tomosynthesis image over one of the plurality of images. ### Claim 33 (depends on 22) The method of claim 22, further comprising obtaining an additional plurality of images, and updating the digital tomosynthesis image using the subset of the plurality of images and at least one of the additional plurality of images. ### Claim 34 (depends on 22) The method of claim 22, wherein the plurality of images comprises different image sets, each of the image sets comprises images that correspond with a phase or a phase range of a physiological cycle, and wherein the digital tomosynthesis image is generated using one of the image sets. ### Claim 35 (depends on 34) The method of claim 34, wherein the images in each of the image sets have a substantially uniform angular spacing. ### Claim 36 (depends on 22) The method of claim 22, further comprising: obtaining a portion of a volumetric image that corresponds with a plane of the tomosynthesis image; and comparing the portion of the volumetric image with the tomosynthesis image. ### Claim 37 (depends on 22) The method of claim 22, further comprising: determine an additional digital tomosynthesis images using at least some of the plurality of images obtained while the radiation source is at the different positions along the arc path; and outputting the digital tomosynthesis images and the additional digital tomosynthesis image for display in a form of a video. ### Claim 38 (depends on 22) The method of claim 22, wherein the arc path is rectilinear with a corresponding infinite arc radius. ### Claim 39 An imaging system, comprising: a radiation source; a positioner configured to rotate the radiation source along an arc path at a rate that is a equal to or less than Rmax, Rmax being calculated from α and T, and being equal to α/T wherein the rate is a speed of rotation of the radiation source when the radiation source is rotating; an imager in operative position relative to the radiation source, wherein the radiation source and the imager are configured to obtain a plurality of images while the radiation source is at different positions along the arc path; and a processor configured to determine a digital tomosynthesis image using a subset of the plurality of images; wherein α is an angular spacing between a subset of the images that belongs to a same bin, and T is a period of a physiological motion, wherein at least two images in the subset of the images belonging to the same bin correspond with two different respective positions of the radiation source; and wherein the imaging system further comprises a processing module configured to calculate Rmax based on the angular spacing. ### Claim 40 An imaging system, comprising: a radiation source; a positioner configured to rotate the radiation source along an arc path at a rate that is a equal to or less than Rmax, Rmax being calculated from α and T, and being equal to α/T, wherein the rate is a speed of rotation of the radiation source when the radiation source is rotating; an imager in operative position relative to the radiation source, wherein the radiation source and the imager are configured to obtain a plurality of images while the radiation source is at different positions along the arc path; and a processor configured to determine a digital tomosynthesis image using a subset of the plurality of images; wherein α is an angular spacing between a subset of the images that belongs to a same bin, and T is a period of a physiological motion, wherein at least two images in the subset of the images belonging to the same bin correspond with two different respective positions of the radiation source; and wherein the imaging system further comprises a processing module configured to calculate Rmax, based on the period of the physiological motion. ### Claim 41 An imaging method, comprising: generating a control signal to control a positioner to rotate a radiation source through an arc path at a rate that is less than or equal to Rmax, Rmax, being calculated from α and T using a processing unit, and being equal to α/T, wherein the rate is a speed of rotation of the radiation source when the radiation source is rotating; and obtaining a plurality of images that are generated using radiation from the radiation source while the radiation source is at different positions along the arc path; and determining a digital tomosynthesis image using a subset of the plurality of images; wherein α is an angular spacing between a subset of the images that belongs to a same bin, and T is a period of a physiological motion, wherein at least two images in the subset of the images belonging to the same bin correspond with two different respective positions of the radiation source; and wherein the imaging method further comprises calculating Rmax based on the angular spacing. ### Claim 42 An imaging method, comprising: generating a control signal to control a positioner to rotate a radiation source through an arc path at a rate that is less than or equal to Rmax, Rmax being calculated from α and T using a processing unit, and being equal to α/T, wherein the rate is a speed of rotation of the radiation source when the radiation source is rotating; and obtaining a plurality of images that are generated using radiation from the radiation source while the radiation source is at different positions along the arc path; and determining a digital tomosynthesis image using a subset of the plurality of images; wherein α is an angular spacing between a subset of the images that belongs to a same bin, and T is a period of a physiological motion, wherein at least two images in the subset of the images belonging to the same bin correspond with two different respective positions of the radiation source; and wherein the imaging method further comprises calculating Rmax, based on the period of the physiological motion. ### Claim 43 An imaging system, comprising: a processing module configured to calculate a maximum rate of rotation based on an angular spacing between two images to be formed; a radiation source; a positioner configured to rotate the radiation source along an arc path at a rate that is less than 0.25 degree/second, wherein the rate is a speed of rotation of the radiation source when the radiation source is rotating; and an imager in operative position relative to the radiation source, wherein the radiation source and the imager are configured to obtain a plurality of images that includes the two images while the radiation source is at different positions along the arc path. ### Claim 44 An imaging system, comprising: a radiation source; a positioner configured to rotate the radiation source along an arc path at a rate that is less than 0.25 degree/second, wherein the rate is a speed of rotation of the radiation source when the radiation source is rotating; an imager in operative position relative to the radiation source, wherein the radiation source and the imager are configured to obtain a plurality of images while the radiation source is at different positions along the arc path; and a processing module configured to calculate a maximum rate of rotation based on a period of a physiological motion. ### Claim 45 An imaging method, comprising: calculating a maximum rate of rotation for a radiation source based on an angular spacing between images that belongs to a same bin; generating a control signal to control a positioner to rotate the radiation source through an arc path at a rate that is less than 0.25 degree/second, wherein the rate is a speed of rotation of the radiation source when the radiation source is rotating; and obtaining the images that are generated using radiation from the radiation source while the radiation source is at different positions along the arc path. ### Claim 46 An imaging method, comprising: calculating a maximum rate of rotation for a radiation source based on a period of physiological motion; generating a control signal to control a positioner to rotate the radiation source through an arc path at a rate that is less than 0.25 degree/second, wherein the rate is a speed of rotation of the radiation source when the radiation source is rotating; and obtaining a plurality of images that are generated using radiation from the radiation source while the radiation source is at different positions along the arc path.