Abstract: An imaging system for performing tomosynthesis on a region of an object comprises an x-ray source, motion controller, an x-ray detector and a processing unit. The x-ray source is positioned at a predetermined distance from the object and continuously moves along a path relative to the object at a plurality of predetermined locations. The x-ray source transmits x-ray radiation through the region of the object. The motion controller is coupled to the x-ray source and continuously moves the x-ray source along the path relative to the object. The x-ray source minimizes vibration in the imaging system due to continuous movement. The x-ray detector is positioned at a predetermined distance from the x-ray source and detects the x-ray radiation transmitted through the region of the object, thus acquiring x-ray image data representative of the region of the object. The processing unit is coupled to the x-ray detector for processing the x-ray image data into at least one tomosynthesis image of the region of the object.

Abstract: A technique is provided for visualizing a volume of interest, such as may be acquired by a tomosynthesis imaging system. The technique provides for the use of one or more weighting functions, such as depth-dependent weighting functions, in the determination of pixel values in a volume rendering. The weighting functions may modify, for example, an intensity determination for a pixel, either directly or by modifying other contributing functions, such as for determining occlusion effects. The volume rendering may then be displayed for review by a technologist or clinician.

Abstract: A method reconstructs 3-dimensional information of an object from projection images of said object acquired by a digital tomosynthesis system having an x-ray source following a trajectory relative to the object and a detector. The method comprises determining mathematical relationships between Fourier Transforms of logical slices through the object and Fourier Transforms of projection images of the object. Moreover, a digital tomosynthesis system includes a detector and an x-ray source traversing a trajectory a constant distance from a plane containing the detector. A computer of the digital tomosynthesis system reconstructs 3-dimensional images of an object by determining mathematical relationships between Fourier Transforms of logical slices through the object with Fourier Transforms of projection images of the object.

Abstract: Geometry of a tomosynthesis system including a detector and an x-ray source is determined using fiducial markers with non-determined positions. The geometry is determined by arbitrarily identifying at least two markers within an imaged volume, at different relative distances between the detector and the x-ray source, without having projections located on a straight line for all different source positions, and locating the projections of the markers within at least two images acquired of the imaged volume. The at least two images correspond to different positions of a focal spot of the x-ray source.

Abstract: Systems and methods that utilize asymmetric geometry to acquire radiographic tomosynthesis images are described. Embodiments comprise tomosynthesis systems and methods for creating a reconstructed image of an object from a plurality of two-dimensional x-ray projection images. These systems comprise: an x-ray detector; and an x-ray source capable of emitting x-rays directed at the x-ray detector; wherein the tomosynthesis system utilizes asymmetric image acquisition geometry, where ?1??0, during image acquisition, wherein ?1 is a sweep angle on one side of a center line of the x-ray detector, and ?0 is a sweep angle on an opposite side of the center line of the x-ray detector, and wherein the total sweep angle, ?asym, is ?asym=?1+?0. Reconstruction algorithms may be utilized to produce reconstructed images of the object from the plurality of two-dimensional x-ray projection images.

Abstract: A digital tomosynthesis system acquires a plurality of projection radiographs of an object and reconstructs structures of the object based on the acquired projection radiographs. The digital tomosynthesis system includes an x-ray source and a detector. The x-ray source emits a beam of x-rays, and moves in a linear trajectory relative to the detector.

Abstract: Geometry of a tomosynthesis system including a detector and an x-ray source is determined using fiducial markers with non-determined positions. The geometry is determined by arbitrarily identifying at least two markers within an imaged volume, at different relative distances between the detector and the x-ray source, without having projections located on a straight line for all different source positions, and locating the projections of the markers within at least two images acquired of the imaged volume. The at least two images correspond to different positions of a focal spot of the x-ray source.

Abstract: A digital tomosynthesis system acquires a plurality of projection radiographs of an object and reconstructs structures of the object based on the acquired projection radiographs. The digital tomosynthesis system includes an x-ray source and a detector. The x-ray source emits a beam of x-rays, and moves in a linear trajectory relative to the detector.

Abstract: A method reconstructs 3-dimensional information of an object from projection images of said object acquired by a digital tomosynthesis system having an x-ray source following a trajectory relative to the object and a detector. The method comprises determining mathematical relationships between Fourier Transforms of logical slices through the object and Fourier Transforms of projection images of the object. Moreover, a digital tomosynthesis system includes a detector and an x-ray source traversing a trajectory a constant distance from a plane containing the detector. A computer of the digital tomosynthesis system reconstructs 3-dimensional images of an object by determining mathematical relationships between Fourier Transforms of logical slices through the object with Fourier Transforms of projection images of the object.

Abstract: A technique is provided for reducing contrast variability in images produced by tomosynthesis. In particular, contrast variability in images produced by a radiation source which has a linear or elongated scan path is reduced. The technique filters the radiographic projections or the reconstructed image slices in a direction transverse to the scan-direction of the radiation source to reduce contrast variations related to the orientation of the structure and the scan geometry.

Abstract: A method for acquiring a plurality of images of an object of interest using a tomosynthesis imaging system. The method includes determining a thickness of an object of interest, and adjusting at least one parameter of an image acquisition process based on the determined thickness.

Abstract: A tomosynthesis system for forming a three dimensional image of an object is provided. The system includes an X-ray source adapted to irradiate the object with a beam of X-rays from a plurality of positions in a sector, an X-ray detector positioned relative to the X-ray source to detect X-rays transmitted through the object and a processor which is adapted to generate a three dimensional image of the object based on X-rays detected by the detector. The detector is adapted to move relative to the object and/or the X-ray source is adapted to irradiate the object with the beam of X-rays such that the beam of X-rays follows in a non arc shaped path and/or a center of the beam of X-rays impinges substantially on the same location on the detector from different X-ray source positions in the sector.

Abstract: A technique is provided for reducing contrast variability in images produced by tomosynthesis. In particular, contrast variability in images produced by a radiation source which has a linear or elongated scan path is reduced. The technique filters the radiographic projections or the reconstructed image slices in a direction transverse to the scan-direction of the radiation source to reduce contrast variations related to the orientation of the structure and the scan geometry.

Abstract: An imaging system for performing tomosynthesis on a region of an object comprises an x-ray source, motion controller, an x-ray detector and a processing unit. The x-ray source is positioned at a predetermined distance from the object and continuously moves along a path relative to the object at a plurality of predetermined locations. The x-ray source transmits x-ray radiation through the region of the object. The motion controller is coupled to the x-ray source and continuously moves the x-ray source along the path relative to the object. The x-ray source minimizes vibration in the imaging system due to continuous movement. The x-ray detector is positioned at a predetermined distance from the x-ray source and detects the x-ray radiation transmitted through the region of the object, thus acquiring x-ray image data representative of the region of the object. The processing unit is coupled to the x-ray detector for processing the x-ray image data into at least one tomosynthesis image of the region of the object.

Abstract: A radiation imaging system comprises a movable radiation source adapted to be disposed in a plurality of respective radiation source positions; a radiation detector and a collimator assembly configured to displace a collimator in a plurality of respective collimator positions, each of the collimator positions being coordinated with at least one of the radiation source positions such that a radiation beam emanating from the radiation source is collimated to limit radiation incident on the detector to a predetermined exposure area. Another radiation imaging system comprises a movable radiation source; a radiation detector; and a collimator comprising an adjustable geometry aperture assembly configured such that an adjustment of the aperture geometry is synchronized with the movement of the radiation source and coordinated with the radiation source position so as to limit the incident radiation to a predetermined exposure area at the detector.

Abstract: An imaging system for performing tomosynthesis on a region of an object comprises an x-ray source, motion controller, an x-ray detector and a processing unit. The x-ray source is positioned at a predetermined distance from the object and continuously moves along a linear path relative to the object. The x-ray source transmits x-ray radiation through the region of the object at a plurality of predetermined locations. The motion controller is coupled to the x-ray source and continuously moves the x-ray source along the path relative to the object. The x-ray source minimizes vibration in the imaging system due to continuous movement. The x-ray detector is positioned at a predetermined distance from the x-ray source and detects the x-ray radiation transmitted through the region of the object, thus acquiring x-ray image data representative of the region of the object.

Abstract: There is provided a method of constructing a three dimensional (3D) image of an object from a plurality of two dimensional (2D) views of the object, comprising the steps of filtering the plurality of 2D views of the object, and order statistics-based backprojecting the filtered 2D views into the 3D image of the object.

Abstract: A method for estimating a material composition of an imaged object using an imaging system. The imaging system includes a radiation source and a digital detector. The method also includes scanning a plurality of calibration phantoms with varying material composition to acquire a plurality of reference calibration images, estimating an attenuation coefficient thickness product for each pixel in the reference calibration images, and estimating a material composition of a region of interest using the estimated pixelwise coefficient thickness product.

Abstract: A radiation imaging system comprises a movable radiation source adapted to be disposed in a plurality of respective radiation source positions; a radiation detector and a collimator assembly configured to displace a collimator in a plurality of respective collimator positions, each of the collimator positions being coordinated with at least one of the radiation source positions such that a radiation beam emanating from the radiation source is collimated to limit radiation incident on the detector to a predetermined exposure area. Another radiation imaging system comprises a movable radiation source; a radiation detector; and a collimator comprising an adjustable geometry aperture assembly configured such that an adjustment of the aperture geometry is synchronized with the movement of the radiation source and coordinated with the radiation source position so as to limit the incident radiation to a predetermined exposure area at the detector.

Abstract: At least one metric for a mammographic image is computed by a workstation, and provided on a workstation display along with the mammographic image. A clinician can select one or more different metrics to be computed for an image, as well as where they are to be shown and the manner in which they are to be shown on the display. Speech (may also be an audible sound which is not speech) may also be used in the workstation to audibly provide metrics information to the clinician.