Abstract: To produce 3D x-ray images, it is necessary to compensate for patient movement during the emission and detection of x-rays; this may be achieved by providing an x-ray sensor 20 comprising a digital x-ray detector 40, and an inertial sensor 50, 60 for providing positional information relating to changes in the relative position of the x-ray sensor during detection of x-rays.

Abstract: Alignment of tomosynthesis systems requires operator skill, particularly where regions of interest are internal structures with limited surface features. Reconstruction of an entire 3D tomosynthesis image may require seconds to minutes, and it can take this long before operators realize that subsequent scans are required. In this time, the patient may have moved and a second scan could also potentially miss the region of interest, requiring a third scan, etc. Multiple exposures are time-consuming and increase patient radiation dose. A digital x-ray tomosynthesis system comprises a static array of x-ray emitters and an x-ray detector and involves selecting a sub-set of x-ray emitters so no x-ray detector part is exposed to x-rays from more than nine of the sub-set and generating a composite image from non-overlapping portions of each respective image produced on the x-ray detector. A two-dimensional image of a subject may be produced using minimal radiation dose.

Abstract: The present invention seeks to reduce the burden of producing high-resolution tomograms by using an initial scan on a predetermined grid 10 to obtain a minimal set of images, and then regions of interest 20 are identified for further scanning. The further scanning locations 40 are determined by image entropy or gradient found in the previous iteration; such regions are indicative of edges, cracks or complex structure within the region. After each iteration, the level of information (e.g. image entropy or gradient) will decrease relative to the pixel/voxel size. In this way, a more efficient way to scan is achieved.

Abstract: To obtain functional information 110 energising a first set of x-ray emitters of the panel over a first period of time and directing the x-rays at the first object; using the detector to detect the x-rays 35 after passing through the first object; processing the detected x-rays to create a first set of images to obtain tomosynthesis data 100; energising a second set of x-ray emitters of the panel over a second period of time and directing the x-rays at the first object; using the detector to detect the x-rays after passing through the first object; processing the detected x-rays to create a second set of images to obtain tomosynthesis data, wherein the number of emitters used in the second period of time is less than used in the first period of time; and comparing at least some images from each set of images to provide functional information.

Abstract: Digital Tomosynthesis (DT) is a type of limited angle tomography providing the benefits of 3D imaging. Much like Computerized Tomography (CT), DT allows greater detection of 3D structures by viewing one slice at a time. In contrast to CT, the DT projection dataset is incomplete, which violates the tomographic sufficiency conditions and results in limited angle artefacts in the reconstructed images. The present invention provides a method of producing a tomogram in which reconstruction is performed along lines on the x-ray detector panel 20 defined by a point on the detector panel 20 closest to a point location of the x-ray emitter 10, to a location of a respective pixel on the perimeter of the x-ray detector panel 20. In this way, artefact reduction is achieved, particularly at higher cone beam angles, and at lower stand-off distances.

Abstract: The majority of image reconstruction algorithms are common to DT and CT, and require reconstruction volume allocation and are based on ray tracing techniques. Reconstructed three-dimensional images become available only after the entire volume is processed and the algorithm completes. The present invention performs reconstruction on a slice-by-slice basis, instead of waiting for completion of the algorithm by back-projecting each pixel in each attenuation image towards the emitter that generated that image, onto a selected reconstruction slice and determining a proportion of overlap with grid cells in the slice to obtain weighting factors in order to calculate an average back-projected intensity for each grid cell in the selected reconstruction slice.

Abstract: An x-ray imaging apparatus 10 comprising a support structure 100, the support structure supporting two separate x-ray emitting apparatus, a first x-ray emitting apparatus 130 comprising an x-ray emitter arranged for producing 2D tomosynthesis images, and a second x-ray emitting apparatus 140 comprising an array of distributed x-ray emitters arranged for producing 3D tomosynthesis images, the first and second x-ray emitting apparatus moveable relative to the support structure and arranged such that, in use, one of the first and second x-ray emitting apparatus is moveable into an operative position whereby x-rays are emitted therefrom towards a target 200, and simultaneously the other of the first and second x-ray emitting apparatus is movable into an inoperative position whereby x-rays are not emitted therefrom.

Abstract: An x-ray imaging device (10) comprising at least two substantially planar panels (20, 21), each panel comprising a plurality of x-ray emitters housed in a vacuum enclosure, wherein the at least two panels each have a central panel axis (28) and are arranged such that their central panel axes are non-parallel to one another, the device further comprising a panel retaining means and arranged such that the panel retaining means retains the at least two panels stationary in relation to an object during x-raying of the object.

Abstract: A portable x-ray imaging source (100) capable of motion-free x-ray tomosynthesis, wherein said source is suitable for dental and small body-part/small area imaging.

Abstract: To achieve high quality x-ray imaging, it is important to be able to control the production of x-rays in an x-ray generator. This is achieved by an x-ray generator comprising an array of electron field emitters for producing paths of electrons, target material comprising x-ray photon producing material configured to emit x-ray photons in response to the incidence of produced electrons upon it, an array of magnetic-field generators for affecting the paths of the produced electrons from the array of electron field emitters such that one or more paths are divertable away from the x-ray photon producing material so as to reduce the production of x-ray photons by the said one or more paths of electrons, the generator further comprising a sensing circuit arranged to measure the amount of electrical charge emitted by one or more electron emitter, and a controller for controlling the array of magnetic-field generators in response to the amount of electrical charge measured.

Abstract: The individual emitters are operated in multiple groups each illuminating a region of interest between the emitter array and the detector array such that the cone of radiation rays projected on the detector array from any single emitter in any one such group is substantially spatially separated from the corresponding projected cones from all other emitters in that same group. At least the ROI portion of the 3D space between the emitter panel and the detector panel is represented by 3D volume elements (voxels), wherein at least some of those voxels represent respective portions of that space that are traversed by corresponding portions of a plurality of radiation rays each extending from a respective emitter to a respective detector and are associated with respective absorption coefficients representative of the radiation absorption characteristic of a corresponding portion of the ROI.

Abstract: The individual emitters are operated in multiple groups each illuminating a region of interest between the emitter array and the detector array such that the cone of radiation rays projected on the detector array from any single emitter in any one such group is substantially spatially separated from the corresponding projected cones from all other emitters in that same group. At least the ROI of portion of the 3D space between the emitter panel and the detector panel is represented by 3D volume elements (voxels), wherein at least some of those voxels represent respective portions of that space that are traversed by corresponding portions of a plurality of radiation rays each extending from a respective emitter to a respective detector and are associated with respective absorption coefficients representative of the radiation absorption characteristic of a corresponding portion of the ROI.

Abstract: An x-ray imaging device (10) comprising at least two substantially planar panels (20, 21), each panel comprising a plurality of x-ray emitters housed in a vacuum enclosure, wherein the at least two panels each have a central panel axis (28) and are arranged such that their central panel axes are non-parallel to one another, the device further comprising a panel retaining means and arranged such that the panel retaining means retains the at least two panels stationary in relation to an object during x-raying of the object.

Abstract: An x-ray imaging system and method for reconstructing three-dimensional images of a region of interest from spatially and temporally overlapping x-rays using novel reconstruction techniques are provided. The x-ray imaging system may include a detector to generate a signal in response to x-rays incident upon the detector, wherein the signal indicates the intensity of the x-rays incident upon a pixel of the detector, a plurality of x-ray sources arranged to emit x-rays such that said x-rays pass through a region of interest (ROI) and spatially and temporally overlap at the pixel of the detector, and a processing unit to receive the signal indicating the intensity of x-rays incident upon the pixel of the detector and generate an estimate of the intensity attributable to each of the two or more x-rays overlapping at the pixel of the detector.

Abstract: A method of designing an x-ray emitter panel 100 including the step of determining a pitch scale, r, to be used in placing x-ray emitter elements 110 on the panel 100, thereby arriving at a specific design of x-ray emitter panel 100 suitable for a specific use.

Abstract: An x-ray collimator that may include a substrate containing a plurality of holes, each hole being frustoconical at one end and tubular at the other end for use in an x-ray imaging system, whereby the x-ray collimator may be aligned with a two-dimensional array of x-ray sources and a two-dimensional x-ray sensor, and whereby x-ray photons from the x-ray sources may pass through the collimator holes and emerge as a beam of x-ray photons in a narrow angle cone which may pass through a subject being imaged, positioned between the output holes of the collimator and the x-ray sensor.

Abstract: The disclosed system includes an emitter array for generating x-rays, a detector array for sensing a flux of x-rays transmitted through a region of interest; apparatus for holding, moving and aligning the emitter array relative to the region of interest and the detector array; electronic means for controlling the emitters and for reading and analyzing the output from the detectors and converting it to image data, and a display for displaying and manipulating the image data. The individual emitters are operated in multiple groups each illuminating a region of interest between the emitter array and the detector array such that the cone of radiation rays projected on the detector array from any single emitter in any one such group is substantially spatially separated from the corresponding projected cones from all other emitters in that same group.

Abstract: An x-ray imaging system and method for reconstructing three-dimensional images of a region of interest from spatially and temporally overlapping x-rays using novel reconstruction techniques.

Abstract: An x-ray collimator that may include a substrate containing a plurality of holes, each hole being frustoconical at one end and tubular at the other end for use in an x-ray imaging system, whereby the x-ray collimator may be aligned with a two-dimensional array of x-ray sources and a two-dimensional x-ray sensor, and whereby x-ray photons from the x-ray sources may pass through the collimator holes and emerge as a beam of x-ray photons in a narrow angle cone which may pass through a subject being imaged, positioned between the output holes of the collimator and the x-ray sensor.

Abstract: An x-ray generator may include a plurality of electron field emitters; a target material; a plurality of energisable solenoid coils; and an electronic power and timing circuit. The generator may provide electrical current to at least one individual solenoid coil to create a magnetic field to cause the path of electrons emitted from the emitter closest to the energised solenoid coil to be defocused and/or deflected before the electrons reach the target material. The target material may comprise a low atomic number material and a high atomic number material, the high atomic number material being arranged in a regular pattern, such that, in use, the electrons may be aimed at either the high or the low atomic number material.