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WO2009115982A1 - Dispositif de tomodensimétrie et procédé d'acquisition d'images par tomodensimétrie basés sur des microsources de rayons x réparties dans l'espace du type faisceau conique - Google Patents

Dispositif de tomodensimétrie et procédé d'acquisition d'images par tomodensimétrie basés sur des microsources de rayons x réparties dans l'espace du type faisceau conique Download PDF

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Publication number
WO2009115982A1
WO2009115982A1 PCT/IB2009/051083 IB2009051083W WO2009115982A1 WO 2009115982 A1 WO2009115982 A1 WO 2009115982A1 IB 2009051083 W IB2009051083 W IB 2009051083W WO 2009115982 A1 WO2009115982 A1 WO 2009115982A1
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Prior art keywords
ray
microsources
spatially distributed
array
computed tomography
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Inventor
Gereon Vogtmeier
Joerg Bredno
Rainer Pietig
Michael Grass
Michael Overdick
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Philips Intellectual Property and Standards GmbH
Koninklijke Philips NV
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Philips Intellectual Property and Standards GmbH
Koninklijke Philips Electronics NV
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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/02—Arrangements for diagnosis sequentially in different planes; Stereoscopic radiation diagnosis
    • A61B6/03—Computed tomography [CT]
    • A61B6/032—Transmission computed tomography [CT]
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/02—Arrangements for diagnosis sequentially in different planes; Stereoscopic radiation diagnosis
    • A61B6/027—Arrangements for diagnosis sequentially in different planes; Stereoscopic radiation diagnosis characterised by the use of a particular data acquisition trajectory, e.g. helical or spiral
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/40—Arrangements for generating radiation specially adapted for radiation diagnosis
    • A61B6/4064—Arrangements for generating radiation specially adapted for radiation diagnosis specially adapted for producing a particular type of beam
    • A61B6/4085—Cone-beams
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/50—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment specially adapted for specific body parts; specially adapted for specific clinical applications
    • A61B6/508—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment specially adapted for specific body parts; specially adapted for specific clinical applications for non-human patients
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/58—Testing, adjusting or calibrating thereof
    • A61B6/587—Alignment of source unit to detector unit
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J35/00—X-ray tubes
    • H01J35/02—Details
    • H01J35/04—Electrodes ; Mutual position thereof; Constructional adaptations therefor
    • H01J35/06—Cathodes
    • H01J35/065—Field emission, photo emission or secondary emission cathodes
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/50—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment specially adapted for specific body parts; specially adapted for specific clinical applications
    • A61B6/503—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment specially adapted for specific body parts; specially adapted for specific clinical applications for diagnosis of the heart
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2235/00—X-ray tubes
    • H01J2235/06—Cathode assembly
    • H01J2235/068—Multi-cathode assembly

Definitions

  • the present invention refers to distributed X-ray source computed tomography (CT) based imaging systems and, more particularly, to a CT scanner apparatus and method for a CT -based image acquisition and 3D reconstruction with stationary, partly stationary or non-stationary source-detector setup geometries with at least one detector ring fixedly attached to a gantry and a number of contiguous or partly contiguous radiator arrays, each comprising a number of spatially distributed X-ray microsources of the fan- or cone-beam type, which may preferably be fabricated in carbon nanotube (CNT) technology, thus allowing higher sampling rates for an improved temporal resolution of acquired CT images as needed for an exact reconstruction of fast moving objects (such as e.g.
  • CNT carbon nanotube
  • CNT -type radiator arrays source arrays
  • detector arrays detector arrays as described with reference to exemplary embodiments of the present invention which, within improved sampling constraints as mentioned above, serve to enhance the spatial resolution of the reconstructed images by reducing artifacts that may result from missing or partial available image acquisition data.
  • CT scanning is based on a rectilinear propagation and attenuation of X-rays.
  • a tomographic imaging system thereby acquires a series of X-ray projections from a range of angles around the subject. Each projection represents the value (or collection of values in a multi-element X-ray detector) of the X-ray attenuation line integral through the object along the line from an X-ray source to an X-ray detector.
  • Imaging an object to be graphically reconstructed at equiangular-spaced views over 180° forms a complete set of projection data.
  • Tomographic image reconstruction creates a 2D image (or 3D volume) from the measured projection data. The angular distance between successive projections and the X-ray detector pitch are two of the primary factors controlling the resolution of the reconstructed image.
  • an X-ray source is moved to a few discrete locations for acquiring voxel data for a set of 2D projection images of an object to be graphically visualized, wherein said projection images are taken from distinct projection angles.
  • the voxel data of the obtained set of projection images are then used as input data for a 3D reconstruction algorithm which calculates a three-dimensional view of the object to be displayed on a screen by an image rendering application.
  • Tomosynthesis images thereby provide a limited depth resolution - an improvement on projection radiography - without the expense and increased dose of conventional CT imaging.
  • Micro-CT X-ray microcomputed tomography
  • Micro-CT systems have been used primarily for bone imaging studies due to the high contrast between calcified and soft tissue, but they have also been shown to be effective for soft-tissue imaging, particularly when a contrast medium is employed. These new imaging systems permit researchers to non-invasively screen small animals (such as e.g. mice and rats) for mutations or pathologies and to monitor disease progression and response to therapy.
  • MRM magnetic resonance microscopy
  • an animal e.g. a mouse
  • the image spatial resolution is primarily determined by the X-ray source focal spot size, the detector element size and the system geometry whereas the contrast resolution is principally set by the X-ray flux and detector element size.
  • the available X-ray detector elements were too large to provide the resolution required to image rodents so some early investigators replaced the detector block with a translating X-ray film cassette.
  • the X- ray film was subsequently processed and digitized, providing data sets with sufficient resolution (-150 ⁇ m) to reconstruct useful images of small animal organs.
  • Burstein et al. reported a ⁇ 50- ⁇ m resolution image of a mouse thorax obtained using a conventional X-ray source operated at an electron accelerating potential of 90 kVp and a 512-element linear array of X-ray detectors (cf. Burstein, P. J.; Bjorkholm, R. C; Chase, R. C; Seguin, F. H.: ,,The largest and smallest X-ray computed tomography systems", in: Nucl. Instrum. Methods Phys. Res. 1984; Vol. 221, pp. 207-212). During this period, conventional CT systems were also employed to simultaneously image multiple mice with relatively low resolution (> 800 ⁇ m) but very high throughput (eight mice at a time, 9.6 seconds per image).
  • X-ray source technologies which are based on arrays of spatially distributed, microfabricated multi-pixel X-ray sources using field emission from carbon nanotubes (CNT) are opening up new approaches to X-ray imaging.
  • CNT carbon nanotubes
  • multi-pixel carbon nanotube field emission X-ray sources are used that are capable of generating spatially and temporally modulated radiations.
  • X-ray microsources of the CNT type are small X-ray radiation emitting devices that are made from layers of carbon having a size of a few nanometers.
  • Flannery et al. brought X-ray microtomography into a new era with the introduction of a three-dimensional imaging system using a two-dimensional detector comprising a phosphor plate optically coupled to a charge-coupled detector (CCD) array
  • CCD charge-coupled detector
  • microtomography systems for high-resolution specimen analysis. Most of these systems employ CCD-based detector arrays, micro-focus X-ray tubes, and have reconstructed image resolutions between 20 ⁇ m and 100 ⁇ m. The majority of the studies performed using these instruments focused on high- density tissue such as bone or teeth for which magnetic resonance imaging is less successful.
  • circle-and-line trajectories Zeng, G. L.; Gullberg, G. T.: ,,A cone -beam tomography algorithm for orthogonal circle-and-line orbit
  • Linehan, J.: ,,Feldkamp and circle-and-line cone -beam reconstruction for 3D micro-CT of vascular networks in: Phys. Med. Biol. 43, pp.
  • X-ray imaging e.g. X-ray imaging
  • the present invention uses the fact that microfabricated
  • X-ray sources of the CNT type aside from their small size, are characterized by another attractive feature which consists in that they can be switched on and off very fast. According to the present invention, this switching capability is utilized to replace the moving of a CT or micro-CT gantry with a sequential switching of spatially distributed X-ray microsources.
  • a first exemplary embodiment of the present invention refers to a computed tomography scanner apparatus with a source-detector system which comprises at least one stationarily mounted multi-source radiator array comprising a plurality of spatially distributed, sequentially switchable X-ray microsources addressed by a programmable switching sequence in a contiguous or at least partly contiguous sequential placement fixedly attached to a gantry having a substantial cylindrical gantry opening, said X-ray microsources being configured to emit multiple rays of cone-beam radiation from distinct azimuthal positions around an imaging volume of interest to be graphically visualized by means of X- ray imaging.
  • said source-detector system comprises at least one stationary detector ring carrying a detector array which comprises a number of two or more than two spatially distributed X-ray detectors fixedly attached to said gantry.
  • the total radiator surface size of the at least one multi- source radiator array and the total detector surface size of the at least one detector array, the density of arrangement of said X-ray microsources on each contiguous partial radiator surface of said radiator array and spatial distribution of all contiguous partial radiator surfaces over the interior surface of the substantial cylindrical gantry opening are chosen such that a complete set of 2D projection images is acquired which allows an exact 3D reconstruction of an image volume of interest without blurring or spatial aliasing artifacts.
  • the spatially distributed X-ray microsources of said at least one multi-source radiator array and the spatially distributed X-ray detectors of said at least one detector array may be consecutively placed at adjacent angular positions along the perimetral edge of a polygon or circle lying in a cross-sectional plane perpendicular to the longitudinal symmetry axis of the substantial cylindrical gantry opening such that adjacent X-ray microsources as well as adjacent X-ray detectors do not mutually overlap.
  • the spatially distributed X-ray microsources of said at least one multi-source radiator array and the spatially distributed X-ray detectors of said at least one detector array may be alternately placed at different angular positions or elsehow regularly interleaved along the perimetral edge of a polygon or circle lying in a cross-sectional plane perpendicular to the longitudinal symmetry axis of the substantial cylindrical gantry opening such that adjacent pairs of X-ray microsources and X-ray detectors do not mutually overlap.
  • the spatially distributed X-ray microsources of said at least one multi-source radiator array may be arranged in multiple transversal rows perpendicular to the longitudinal symmetry axis of the substantial cylindrical gantry opening. These rows may have a flat surface aligned with at least one edge segment or edge of a polygon lying in a cross-sectional plane perpendicular to the longitudinal symmetry axis of the substantial cylindrical gantry opening or, alternatively, a curved surface aligned with at least one arc segment of a circle lying in a cross-sectional plane perpendicular to the longitudinal symmetry axis of said gantry opening.
  • the spatially distributed X- ray detectors of said at least one detector array may be arranged on at least one arc segment of a circle lying in a cross-sectional plane perpendicular to the longitudinal symmetry axis of the substantial cylindrical gantry opening, and the spatially distributed X-ray microsources of said at least one multi-source radiator array may be arranged on at least one arc segment of a helical trajectory winding around the longitudinal symmetry axis of the substantial cylindrical gantry opening, wherein the radius of the helical trajectory may be smaller than, equal to or greater than the radius of the circle.
  • each of said arc segments extends over an angular range of more than 180° such that the arc segment of said radiator array and the arc segment of said detector array mutually overlap in an azimuthal direction perpendicular to the longitudinal symmetry axis of the substantial cylindrical gantry opening.
  • the spatially distributed X-ray detectors of said at least one detector array are arranged on at least one arc segment of a first circle lying in a cross-sectional plane perpendicular to the longitudinal symmetry axis of the substantial cylindrical gantry opening, and the spatially distributed X- ray microsources of said at least one multi-source radiator array are arranged on at least one arc segment of a second circle interlocking into the at least one arc segment of said first circle and having the same center coordinates as said first circle, wherein the radius of the second circle may be smaller than, equal to or greater than the radius of the first circle.
  • said first circle and said second circle may be arranged such that said second circle lies in a plane which is inclined by an acute angle with respect to the cross-sectional plane of said first circle.
  • each X-ray microsource may be aligned with a corresponding X- ray detector of said at least one detector array lying diametrically opposite to the respective radiation element, thus being irradiated by the radiation beam emitted from this radiation element.
  • the number of the spatially distributed X-ray microsources contained in the at least one stationarily mounted multi-source radiator array and the number of the spatially distributed X-ray detectors contained in the at least one detector array of the stationary detector ring as well as the switching frequency for sequentially switching said X-ray microsources on or off, respectively, may be chosen such that Ny quist- Shannon's sampling theorem is fulfilled when imaging a moving object so as to exactly reconstruct said object without any temporal aliasing artifacts.
  • the computed tomography scanner apparatus may be adapted to perform a correction method which provides a sufficient image quality.
  • the spatially distributed X-ray microsources of said at least one multi-source radiator array are given by a number of individually addressable single-pixel X-ray microsources of the cone -beam type using field emission cathodes in the form of carbon nanotubes.
  • Using spatially distributed micro fabricated X-ray sources allows a very flexible placement of the respective radiator elements.
  • the above-described placement of multiple CNT -type X-ray microsources in combination with an array of X-ray detectors further allows a good sampling to achieve a proper reconstruction of an object to be graphically visualized.
  • the spatially distributed X-ray microsources of said at least one multi-source radiator array are given by a number of cold emission X-ray microsources or a number of thermal X-ray microsources with a biased cathode for providing a grid switching of the emitted X-ray beams.
  • a second exemplary embodiment of the present invention refers to a computed tomography scanner apparatus with a source-detector system which comprises at least one first multi-source radiator array comprising a plurality of spatially distributed, sequentially switchable X-ray microsources addressed by a programmable switching sequence in a contiguous or at least partly contiguous sequential placement on a gantry having a substantial cylindrical gantry opening, said X-ray microsources being sequentially arranged in at least one transversal row having a curved surface aligned with at least one arc segment of a circle lying in a cross-sectional plane perpendicular to the longitudinal symmetry axis of the substantial cylindrical gantry opening, wherein said X-ray microsources are configured to emit multiple rays of cone -beam radiation from distinct azimuthal positions around an imaging volume of interest to be graphically visualized by means of X-ray imaging.
  • said source-detector system comprises at least one further multi-source radiator array comprising a plurality of spatially distributed X-ray microsources in a contiguous or at least partly contiguous sequential placement, said X-ray microsources being consecutively arranged in any direction orthogonal to the azimuthal direction of the above- mentioned transversal row, wherein said X-ray microsources are configured to emit multiple rays of cone-beam radiation from distinct longitudinal positions parallel to the longitudinal symmetry axis of the substantial cylindrical gantry opening.
  • a detector ring carrying a detector array which comprises a number of two or more than two spatially distributed X-ray detectors arranged on said gantry is provided.
  • the present invention it is further foreseen that size, length and spatial orientation of the at least two multi-source radiator arrays and the total detector surface size of the at least one detector array, the density of arrangement of said X-ray microsources on each contiguous partial radiator surface of said radiator arrays and spatial distribution of all contiguous partial radiator surfaces over the interior surface of the substantial cylindrical gantry opening are chosen such that a complete set of 2D projection images is acquired which allows an exact 3D reconstruction of an image volume of interest without blurring or spatial aliasing artifacts.
  • the present invention thereby proposes different setup geometries arranged for performing a circle-and-line cone -beam 3D reconstruction algorithm.
  • said X-ray microsources may be consecutively arranged in at least one rectilinear, longitudinal column perpendicular to the transversal row of X-ray microsources contained in said first multi-source radiator array.
  • said X-ray microsources may be consecutively arranged in at least one curvilinear column orthogonal to the above-mentioned transversal row.
  • This line scan can be regarded as an add-on to the conventional short-scan circular path.
  • a 3D reconstruction algorithm which is performed based on such a circle-and-line setup geometry has been proven as theoretically exact, possesses an efficient, shift- invariant filtered back-projection (FBP) structure and solves the long object problem.
  • FBP shift- invariant filtered back-projection
  • said gantry is non- rotationally mounted to a stationary mounting unit and wherein the spatially distributed X-ray microsources of said at least one further multi-source radiator array are fixedly attached to this stationary mounting unit (configuration #1).
  • said gantry is rotationally mounted to a stationary mounting unit for journaling said gantry.
  • the spatially distributed X-ray microsources of said at least one further multi-source radiator array may either be fixedly attached to the stationary mounting unit (configuration #2), which requires that the at least one further multi-source radiator array is used for detection irradiation when the corresponding detectors of the at least one detector array are in the diametrically opposed position, or fixedly attached to the rotational gantry and thus being moved together with said at least one first multi-source radiator array and said at least one detector array around the longitudinal symmetry axis of the substantial cylindrical gantry opening in case of rotational movements of the rotational gantry about this axis (configuration #3).
  • the detector array, the at least one first multi-source radiator array and/or the at least one further multi-source radiator array are rotationally movable in an azimuthal direction about the aforementioned longitudinal symmetry axis of the substantial cylindrical gantry opening relative to said gantry.
  • this X-ray source would have to be moved in two orthogonal directions to achieve the same result, or the patient table would have to be moved. Both solutions are not optimal since components of the examination system would have to be moved (the X-ray tube or the patient table), which may result in inconsistent data acquisition as given by movement artefacts or speed limitations.
  • the computed tomography scanner apparatus may thereby be adapted for performing an image acquisition in an azimuthal direction along the circular arc segment of the transversal row of X-ray microsources contained in said at least one first multi-source radiator array (arc acquisition), said arc acquisition covering an azimuthal range of 180° at maximum, and a further image acquisition in a direction covering the entire length of a rectilinear (line acquisition) or curvilinear column of X-ray microsources (further arc acquisition) orthogonal to this circular arc segment as contained in said at least one further multi-source radiator array.
  • a third exemplary embodiment of the present invention is directed to an image processing, visualization and archiving system comprising a computed tomography scanner apparatus as described above.
  • a fourth exemplary embodiment of the present invention is dedicated to a method for operating a computed tomography scanner apparatus as described above with reference to said first exemplary embodiment.
  • Said method thereby comprises the steps of sequentially switching on individual consecutive columns of X-ray microsources contained in said at least one multi-source radiator array, said columns being arranged parallel to the longitudinal symmetry axis of the substantial cylindrical gantry opening, for a predefined image acquisition time, thereby using a constant switching frequency which is chosen such that Nyquist-Shannon's sampling theorem is fulfilled when imaging a moving object so as to reconstruct said object without any temporal aliasing artifacts. After said image acquisition time has expired, they are sequentially switched off.
  • the steps of sequentially switching individual consecutive columns of X-ray microsources on or off, respectively may be cyclically repeated at a constant repetition rate.
  • Said repetition rate may be chosen such that each column of X-ray microsources is switched on and off once per switching cycle. It may be foreseen, however, that some of these X-ray microsources may be switched on and off several times in one scanning sequence so as to enhance the temporal resolution of the scanned image sequence and/or improve the obtained 2D intensity profiles in terms of their signal-to-noise ratios.
  • a fifth exemplary embodiment of the present invention is dedicated to a method for operating a computed tomography scanner apparatus as described above with reference to said second exemplary embodiment.
  • this method thereby comprises the steps of sequentially switching on individual consecutive columns of X-ray microsources contained in said at least two multi-source radiator arrays, said columns being arranged parallel to the longitudinal symmetry axis of the substantial cylindrical gantry opening, for a predefined image acquisition time, thereby using a constant switching frequency which is chosen such that Nyquist-Shannon's sampling theorem is fulfilled when imaging a moving object so as to reconstruct said object without any temporal aliasing artifacts. After said image acquisition time has expired, they are sequentially switched off.
  • the steps of sequentially switching individual consecutive columns of X-ray microsources on or off, respectively, may also be cyclically repeated at a constant repetition rate, and said repetition rate may also be chosen such that each column of X-ray microsources is switched on and off once per switching cycle.
  • image data may be acquired in azimuthal direction along the circular arc segment of the transversal row of X-ray microsources contained in said at least one first multi-source radiator array (arc acquisition), said arc acquisition covering an azimuthal range of 180° at maximum, and in a further direction, thereby covering the entire length of a rectilinear column of X-ray microsources orthogonal to this circular arc segment as contained in said at least one further multi-source radiator array (line acquisition).
  • image data may be acquired in azimuthal direction along the circular arc segment of the transversal row of X-ray microsources contained in said at least one first multi-source radiator array, said arc acquisition covering an azimuthal range of 180° at maximum, and in a further direction, thereby covering the entire length of a curvilinear column of X-ray microsources orthogonal to this circular arc segment as contained in said at least one further multi-source radiator array.
  • the image data is reconstructed with the aid of a circle-and-line cone -beam reconstruction algorithm, thereby acquiring a number of 2D projection images from different angular positions of a circular trajectory, augmented with further 2D projection images obtained by a linear scan along a longitudinal path segment perpendicular to the circular trajectory.
  • a circle-and-line cone -beam reconstruction algorithm thereby acquiring a number of 2D projection images from different angular positions of a circular trajectory, augmented with further 2D projection images obtained by a linear scan along a longitudinal path segment perpendicular to the circular trajectory.
  • the proposed circle-and-line geometry setup allows a complete data acquisition resulting in exact object recovery.
  • the circle-and-line algorithm produces superior 3D reconstructions compared to the Feldkamp algorithm.
  • a computer program product for executing a method as described above with reference to said fourth or fifth exemplary embodiment, respectively, when being implemented and running on a control unit for controlling said computed tomography scanner apparatus.
  • Fig. Ia shows a configuration of a conventional CT scanner apparatus as known from the prior art
  • Fig. Ib shows a schematic block diagram of the CT scanner apparatus illustrated in Fig. Ia
  • Fig. 2 is a schematic view of a multi-source, multi-detector X-ray imaging system utilizing three X-ray tubes and detectors as in a configuration according to the prior art
  • Fig. 3 shows a schematic diagram of a fourth-generation 3D-rotational CT system according to the prior art (see left part of the figure) as well as a conventional multiplexing imaging system using a nine-pixel X-ray source and a digital area detector (see right part of this figure), wherein a single-pixel X-ray tube is mechanically rotated around a patient to be non-invasively examined by means of radiographic imaging, so as to acquire a set of 2D projection images from an anatomical or pathological object of interest in the interior of said patient's body,
  • Fig. 4 shows a detailed view of one X-ray pixel of a multi-pixel X-ray source as known from the prior art, wherein each individual X-ray pixel of the depicted multi-pixel X-ray source is comprised of a CNT -based field emission cathode, a dielectric spacer with a thickness of e.g. 150 ⁇ m, an extraction gate and a focusing electrode, wherein the cathode is realized as a thin CNT composite film deposited on a metal substrate by electrophoresis and wherein pulsing of the X-ray radiation is realized by applying a pulsed voltage signal with desired pulse width and repetition rate to the gate of the corresponding MOSFET circuit, and Figs. 5a-h show eight distinct source-detector setup geometries for the computed tomography scanner apparatus according to the present invention, and
  • Fig. 6 shows a flowchart illustrating the process of the proposed method according to said fourth or fifth exemplary embodiment of the present invention, respectively.
  • a conventional CT imaging system 100 as known from the prior art (such as disclosed in US 6,937,689 B2) is shown which comprises a rotational gantry 101 rotating about the longitudinal axis 108 of a patient's body 107 or any other object to be examined, said rotational gantry 101 having at least one X-ray source or tube 102 that projects a beam of X-rays 106 towards an X-ray detector array 103 placed at the opposite side of said gantry.
  • the X-ray detector array 103 is equipped with a plurality of detector elements 103a which together sense the projected X-rays passing through the patient's body 107 to be examined between X-ray detector array 103 and X-ray source 102.
  • Each detector element 103a generates an electrical signal that represents the intensity of an impinging X- ray beam and can hence be used to estimate the attenuation of the beam as it passes through the object.
  • a 3D volume is calculated by reconstructing and stacking individual 2D slices.
  • Most recently developed micro-CT systems employ two-dimensional detector arrays, allowing the acquisition of a truly three-dimensional data set. Since the initial work by Feldkamp et al.(cf. Feldkamp, L. A.; Davis, L. C; Kress, J. W.: ,,Practical cone-beam algorithm"; in: J Opt. Soc. Am. 1984; Vol. 1, pp. 612-619), 3D cone -beam reconstruction algorithms have become an active area of research.
  • Dusaussoy developed a Radon inversion, exact cone-beam reconstruction method that is effective independent of cone angle size (cf. Dusaussoy, N. J. : ,,VOIR, a volumetric image reconstruction algorithm based on Fourier techniques for inversion of the 3-D radon transform"; in: IEEE Trans Image Process. 1996; Vol. 5, pp. 121- 131).
  • Schaller et al. have developed a fast, approximate cone-beam reconstruction algorithm suitable for small cone angles and an efficient Radon-inversion method for exact cone-beam reconstruction (cf.
  • Feldkamp remains the most commonly employed cone -beam reconstruction method because of its straightforward implementation and its applicability to practical tomography systems.
  • Feldkamp' s algorithm is a 3D backprojection method that can be derived directly from the fan-beam equations for filtered backprojection. It is an approximate solution, but has tremendous practical utility for most cone -beam tomography applications.
  • a multi-slice detector array such as denoted by reference number 103 comprises a plurality of parallel rows of detector elements 103a such that projection data corresponding to a plurality of quasi-parallel or parallel slices can be acquired simultaneously during a scan.
  • an area detector may be utilized to acquire cone -beam data.
  • the detector elements 103 a may completely encircle the patient 107.
  • Fig. Ib also shows a single X-ray source 102; however, many such X-ray sources may be positioned around gantry 101.
  • Control mechanism 109 includes an X-ray controller 110 that provides power and timing signals to one or more X-ray sources 102.
  • a data acquisition system 111 (DAS) belonging to said control mechanism 109 samples analog data from detector elements 103 a and converts the data to digital signals for subsequent processing.
  • An image reconstructor 112 receives sampled and digitized X-ray data from DAS 111 and performs high-speed image reconstruction. The reconstructed image is applied as an input to a computer 113, which stores the image in a mass storage device 114.
  • the image reconstructor 112 may be specialized hardware residing in computer 113 or a software program executed by this computer.
  • the computer 113 also receives signals via a user interface or graphical user interface (GUI). Specifically, said computer receives commands and scanning parameters from an operator console 115 which in some configurations may include a keyboard and mouse (not shown).
  • GUI graphical user interface
  • An associated display 116 e.g., a cathode ray tube display
  • the operator- supplied commands and parameters are used by computer 113 to provide control signals and information to X-ray controller 110, DAS 111, and a table motor controller 117 (also referred to as ,,movement controller”) in communication with a patient table 104, which controls a motorized patient table 104 so as to position patient 107 in gantry 101.
  • patient table 104 moves said patient 107 through gantry opening 105.
  • computer 113 comprises a storage device 118 (also referred to as ,,media reader”), for example, a floppy disk drive, CD-ROM drive, DVD drive, magnetic optical disk (MOD) device or any other digital device including a network connecting device such as an Ethernet device for reading instructions and/or data from a computer-readable medium, such as a floppy disk 119, a CD-ROM, a DVD or another digital source such as a network or the Internet, as well as yet to be developed digital means.
  • computer 113 executes instructions stored in firmware (not shown).
  • the computer may be programmed to perform functions described herein, and as used herein, the term ,,computer” is not limited to just those integrated circuits referred to in the art as computers, but broadly refers to computers, processors, microcontrollers, microcomputers, programmable logic controllers, application specific integrated circuits and other programmable circuits, and these terms are used interchangeably herein.
  • Fig. 2 an interior view of a gantry 101 of a computed tomography (CT) imaging system that does not require a rotating X-ray source is illustrated.
  • CT computed tomography
  • a first, second and third X-ray source 201a, 201b and 201c are used to generate respective X-rays 203a, 203b and 203c. These sources are representative of many such sources surrounding gantry 101.
  • Each of X-rays 203a, 203b and 203c impinge upon a corresponding detector segment 202a, 202b and 202c of detector 103 shown in Figs. Ia and Ib.
  • each of the X-ray sources, X-rays, and detectors are fixed relative to one another.
  • a few representative examples are shown as X-ray sources 201a, 201b and 201c, X-rays 203a, 203b and 203c and detectors 202a, 202b and 202c.
  • One or multiple sources may be activated during a certain scanning interval.
  • Such systems can be substantially faster in the generation of an image than systems using a rotating gantry.
  • Faster scan times are achievable because the location of the source of the X-ray beam used for scanning can be electronically switched, thereby making fast cardiac imaging possible.
  • Power levels can be reduced relative to rotating gantry configurations because imaging system configurations of the present invention can be positioned closer to the patient, thereby reducing the emitted X-ray intensities needed for imaging.
  • an optimal time-sequential sampling pattern is provided. Projections are collected in a range from 0° to 360°, subject to a time-sequential constraint that there is only one projection acquired at any time instant. Thus, the sampling is considered time-sequential.
  • the sampling pattern specifies the angular position of which projection data set, i.e. the angular orientation of the view, to collect at any given time. It is optimal in the sense that it maximizes the temporal inter-projection interval, while providing a method for eliminating motion artifacts. This method can also be extended to configurations in which multiple sources are turned on simultaneously.
  • FIG. 3 shows a schematic diagram of a conventional CT scanner 300a (see left part of the figure) in comparison with a conventional multi-beam X-ray source 300b (see right part of the figure) as described in the study ,,Multiplexing radiography using a carbon nanotube based X-ray source" (in: Appl. Phys. Lett. 89, 064106 (2006); DOL 10.1063/1.2234744; published: August 9, 2006) by J. Zhang, G. Yang and Y. Z.
  • multiplexing radiography is a feasible approach that enables parallel imaging (which means a simultaneous collection of multiple projection images) by means of commonly known frequency multiplexing techniques.
  • parallel imaging which means a simultaneous collection of multiple projection images
  • frequency multiplexing techniques With such a computed tomography system, both a drastic increase of the image acquisition speed and a significant reduction of the emitted X-ray peak power can be achieved without compromising the obtained imaging quality.
  • the general term of multiplexing means a process to combine multiple data channels to form one composite data stream for transmission on a common medium.
  • Demultiplexing is the recovering of the original separate channels from a multiplexed signal.
  • X-ray tubes such as referred to by reference number 301 in the left part of Fig. 3, are single-pixel devices that generate radiation from one focal point (herein also referred to as ,,pixel") on the X-ray anode.
  • ,pixel focal point
  • mechanical motion of either the X-ray source 301 and the irradiated X-ray detector array 302 placed diametrically opposite to the X-ray source or the object O to be graphically visualized is required to obtain a set of 2D projection images that are needed for a 3D reconstruction of the object.
  • the radiation wave form can not be readily programmed, which makes coding and decoding difficult.
  • a multi-pixel X-ray source which uses carbon nanotubes (CNTs) as the field emission cathode, is able to generate a plurality of spatially distributed X-ray beams (pixels) with a programmable intensity, pulse width, and repetition rate.
  • the X-ray pixels are individually addressable through simple electronics. Spatially distributed X-ray source technology thus opens the door for system configurations such as stationary CT scanners that record the multiple views without mechanical motion of the gantry and multiplexing tomographic imaging, both of which have the potential to significantly increase the CT imaging speed.
  • the principle of multiplexing imaging can be explained by a conventional multi-beam X-ray source configuration 300b comprising a multi-beam X-ray source 303 and a flat panel X-ray detector 304 according to the prior art as shown in the right part of Fig. 3 which performs an image acquisition technique based on the orthogonal frequency division multiplexing (OFDM) algorithm.
  • the employed multi-beam X-ray source 303 in the depicted configuration comprises a linear array of nine CNT electron field emission cathodes, a shared common gate, electrostatic focusing optics and a molybdenum target housed in 10 "8 Torr vacuum.
  • FIG. 4 A detailed schematic view showing one pixel of a multi-pixel X-ray source as known from the prior art is depicted in Fig. 4.
  • a rheostat R D may be put in series with each CNT cathode 404, which also functioned as a ballast resistor to minimize the current fluctuation.
  • Gate voltage U g and rheostat R D of the depicted configuration are calibrated to achieve the desired current and thus X-ray flux from each pixel.
  • Voltage U/ of a electrostatic focusing electrode 402 is adjusted for each pixel to obtain a uniform 200 ⁇ m focal spot size for all nine pixels.
  • voltage U a at the anode 401 is stationary at a voltage level of e.g.
  • Activation and modulation of X-ray radiation are achieved by programming the input voltage pulse train which is applied to the gate electrode G of the metal-oxide semiconductor field effect transistor (MOSFET) control circuit 405 connected to the CNT cathode 404 (see Fig. 4), which serves as a toggle switch.
  • MOSFET metal-oxide semiconductor field effect transistor
  • the radiation from a particular pixel is switched on when the input voltage at the corresponding MOSFET gate is equal to 5 V and is switched off when it is equal to 0 V.
  • Fig. 5a shows a first setup geometry of a computed tomography scanner apparatus according to a first configuration of the present invention's first exemplary embodiment which comprises a stationarily mounted multi-source radiator array RA comprising a plurality of spatially distributed X-ray microsources MS (herein also referred to as radiator elements indicated by reference sign ,,R”) in a contiguous sequential placement fixedly attached to a gantry having a substantial cylindrical gantry opening, said X-ray microsources being configured to emit multiple rays of cone-beam radiation from distinct azimuthal positions around an imaging volume of interest to be graphically visualized by means of X-ray imaging.
  • X-ray microsources being configured to emit multiple rays of cone-beam radiation from distinct azimuthal positions around an imaging volume of interest to be graphically visualized by means of X-ray imaging.
  • said setup geometry comprises at least one stationary detector ring which carries a detector array DA comprising three pairwise adjacent rectangular X-ray detector plates D (flat panel detectors) fixedly attached to said gantry.
  • the X-ray microsources MS are given by a number of switchable radiation elements R that are addressed by a programmable switching sequence for being sequentially switched on or off, respectively.
  • the spatially distributed X-ray microsources MS (radiator elements R) of said multi-source radiator array RA are consecutively placed at adjacent angular positions along the perimeter of a half circle lying in a cross-sectional plane perpendicular to the longitudinal symmetry axis of the substantial cylindrical gantry opening. They are arranged in three transversal rows RAi, RA 2 and RA3 perpendicular to the longitudinal symmetry axis (not shown) of the cylindrical gantry, which is assumed as pointing in the z-direction of a 3D Cartesian coordinate system spanned by the three orthogonal coordinate axes x, y and z (not shown).
  • N regular 2N-sided polygon
  • said transversal rows have a curved surface aligned with an 180° arc segment of a circle lying in a cross- sectional plane perpendicular to the longitudinal symmetry axis of the substantial cylindrical gantry opening.
  • the spatially distributed X-ray microsources MS (radiator elements R) of said multi-source radiator array RA are arranged on Nplanar radiator fields which are consecutively placed at adjacent angular positions along the perimetral edges of the aforementioned regular 2N-sided polygon, each radiator field comprising K-L X-ray microsources (with K, L » 100) consecutively arranged in the longitudinal and transversal direction, respectively.
  • Fig. 5b shows a second setup geometry of a computed tomography scanner apparatus according to a second configuration of the present invention's first exemplary embodiment which also comprises a stationarily mounted multi-source radiator array RA comprising a plurality of spatially distributed X-ray microsources MS (radiator elements R) fixedly attached to a gantry having a substantial cylindrical gantry opening. This time, however, they are arranged in a partly contiguous sequential placement interleaved with three spatially distributed rectangular X-ray detector plates D (flat panel detectors) of a detector array DA, wherein the latter is also fixedly attached to said gantry (in the following referred to as ,,first interleaved arrangement").
  • X-ray microsources MS radiation element R
  • Said X-ray microsources are again configured to emit multiple rays of cone-beam radiation from distinct azimuthal positions around an imaging volume of interest to be graphically visualized by means of X-ray imaging.
  • said X-ray microsources MS are given by a number of switchable radiation elements R that are addressed by a programmable switching sequence for being sequentially switched on or off, respectively.
  • the X-ray microsources MS of said radiator array RA are arranged in three transversal rows RAi, RA 2 and RA 3 perpendicular to the longitudinal symmetry axis of the substantial cylindrical gantry opening, which is again assumed as pointing in the z-direction of a 3D Cartesian coordinate system spanned by the three orthogonal coordinate axes x, y and z.
  • the spatially distributed detector plates D of said detector array DA are placed at the remaining angular positions along the perimetral edges of said hexagon. Again, this arrangement is such that adjacent X-ray microsources MS as well as adjacent X-ray detectors D do not mutually overlap.
  • said transversal rows have a flat surface, each aligned with an perimetral edge segment of the hexagon lying in the respective cross-sectional plane.
  • setup geometries with smaller source arrays and larger detectors than depicted in Fig. 5b, setup geometries with larger source arrays and smaller detectors than depicted in Fig. 5b or setup geometries where the X-ray microsources MS of the radiator array RA are closer to or more far away from the hexagon center than the X-ray detectors D of the detector array DA may be foreseen.
  • a third setup geometry of a computed tomography scanner apparatus according to a third configuration of the present invention's first exemplary embodiment is shown that also comprises a stationarily mounted multi-source radiator array RA comprising a plurality of spatially distributed X-ray microsources MS (radiator elements R) fixedly attached to a gantry having a substantial cylindrical gantry opening.
  • X-ray microsources MS of said radiator array RA as well as the detector plates D of said detector array DA are consecutively arranged.
  • Said X-ray microsources are again configured to emit multiple rays of cone-beam radiation from distinct azimuthal positions around an imaging volume of interest to be graphically visualized by means of X- ray imaging.
  • said X-ray microsources MS are given by a number of switchable radiation elements R that are addressed by a programmable switching sequence for being sequentially switched on or off, respectively.
  • the spatially distributed X- ray detectors D of said detector array DA are arranged on at least one arc segment of a circle lying in a cross-sectional plane perpendicular to the longitudinal symmetry axis of the substantial cylindrical gantry opening, and the spatially distributed X-ray microsources MS of said stationary multi-source radiator array RA are arranged on at least one arc segment of a helical trajectory winding around the longitudinal symmetry axis of the substantial cylindrical gantry opening, wherein each of said arc segments may extend over an angular range of more than 180° and thus may mutually overlap in an azimuthal direction perpendicular to said longitudinal symmetry axis.
  • the radius of the helical trajectory is smaller than, equal to or greater than the radius of the circle.
  • the spatially distributed X- ray detectors D of said detector array DA may be arranged on at least one arc segment of a first circle lying in a cross-sectional plane perpendicular to the longitudinal symmetry axis of the substantial cylindrical gantry opening, and the spatially distributed X-ray microsources MS of said stationary multi-source radiator array RA may be arranged on at least one arc segment of a second circle interlocking into the at least one arc segment of said first circle and having the same center coordinates as said first circle, said first circle and said second circle being arranged such that said second circle lies in a plane which is inclined by an acute angle with respect to the cross-sectional plane of said first circle.
  • the radius of said second circle may thereby be smaller than, equal to or greater than the radius of said first circle.
  • Fig. 5d shows a fourth setup geometry of a computed tomography scanner apparatus according to a fourth configuration of the present invention's first exemplary embodiment which also comprises a stationarily mounted multi-source radiator array RA comprising a plurality of spatially distributed X-ray microsources MS (radiator elements R) fixedly attached to a gantry having a substantial cylindrical gantry opening.
  • a stationarily mounted multi-source radiator array RA comprising a plurality of spatially distributed X-ray microsources MS (radiator elements R) fixedly attached to a gantry having a substantial cylindrical gantry opening.
  • Said X-ray microsources are again configured to emit multiple rays of cone -beam radiation from distinct azimuthal positions around an imaging volume of interest to be graphically visualized by means of X-ray imaging.
  • said X-ray microsources MS are given by a number of switchable radiation elements R that are addressed by a programmable switching sequence for being sequentially switched on or off, respectively.
  • areas containing the longitudinal columns of spatially distributed X-ray microsources (R or MS) and areas containing said detector plates D regularly interleave along the perimetral edges of a regular 2N-sided polygon (which for N 11 yields an icosikaidigon) lying in a cross -sectional plane perpendicular to the longitudinal symmetry axis of the substantial cylindrical gantry opening.
  • the spatially distributed detector plates D of said detector array DA are placed at the remaining angular positions along the perimetral edges of the polygon.
  • this arrangement is such that adjacent X-ray microsources MS as well as adjacent X-ray detectors D do not mutually overlap.
  • said columns have a flat surface, each aligned with an perimetral edge segment of the polygon lying in the respective cross-sectional plane.
  • FIG. 5e A fifth setup geometry of a computed tomography scanner apparatus according to a fifth configuration of the present invention's first exemplary embodiment is depicted in Fig. 5e which also shows a stationarily mounted multi-source radiator array RA comprising a plurality of spatially distributed X-ray microsources MS (radiator elements R) fixedly attached to a gantry having a substantial cylindrical gantry opening.
  • Fig. 5e shows a stationarily mounted multi-source radiator array RA comprising a plurality of spatially distributed X-ray microsources MS (radiator elements R) fixedly attached to a gantry having a substantial cylindrical gantry opening.
  • Said X-ray microsources are again configured to emit multiple rays of cone-beam radiation from distinct azimuthal positions around an imaging volume of interest to be graphically visualized by means of X-ray imaging.
  • said X-ray microsources MS are given by a number of switchable radiation elements R that are addressed by a programmable switching sequence for being sequentially switched on or off, respectively.
  • the X-ray microsources MS of said radiator array RA may be arranged in K transversal rows perpendicular to the longitudinal symmetry axis of the substantial cylindrical gantry opening, which is again assumed as pointing in the z-direction of a 3D Cartesian coordinate system spanned by the three orthogonal coordinate axes x, y and z.
  • the spatially distributed detector plates D of said detector array DA are placed at the remaining angular positions along the perimetral edges of the polygon.
  • this arrangement is such that adjacent fields of X-ray microsources MS and said detectors plates D do not mutually overlap.
  • said radiator fields have a flat surface, each aligned with an perimetral edge segment of the polygon lying in the respective cross- sectional plane.
  • a sixth setup geometry of a computed tomography scanner apparatus is depicted in Fig. 5f. It comprises a first multi-source radiator array RAi comprising a plurality of spatially distributed, sequentially switchable X-ray microsources MS (radiator elements R) addressed by a programmable switching sequence in a contiguous or at least partly contiguous sequential placement fixedly attached to a gantry 101 having a substantial cylindrical gantry opening 105, said X-ray microsources being sequentially arranged in at least one transversal row having a curved surface aligned with at least one arc segment of a circle lying in a cross-sectional plane perpendicular to the longitudinal symmetry axis of the substantial cylindrical gantry opening 105, wherein said X-ray microsources MS are configured to emit multiple rays of cone-beam radiation from distinct azimuthal positions around an imaging volume of interest to be graphically visualized by means of X-ray imaging
  • the herein depicted setup geometry additionally comprises a further multi-source radiator array RA 2 comprising a plurality of spatially distributed X-ray microsources MS in a contiguous or at least partly contiguous sequential placement, said X- ray microsources MS being consecutively arranged in any direction orthogonal to the azimuthal direction of the above-mentioned transversal row, wherein said X-ray microsources MS are configured to emit multiple rays of cone -beam radiation from distinct longitudinal positions parallel to the longitudinal symmetry axis of the substantial cylindrical gantry opening 105.
  • a detector ring carrying a detector array DA which comprises a number of two or more than two spatially distributed X-ray detectors D (such as e.g. flat panel detectors) fixedly attached to said gantry may be foreseen.
  • the spatially distributed X-ray microsources MS contained in said first multi-source radiator array RAi are consecutively placed, to be more precisely, at adjacent angular positions along the perimeter of a 180° arc segment of a circle lying in a cross-sectional plane perpendicular to the longitudinal symmetry axis of the substantial cylindrical gantry opening, said 180° arc segment constituting the aforementioned transversal row, wherein the symmetry axis is again assumed as pointing in the z-direction of a 3D Cartesian coordinate system spanned by the three orthogonal coordinate axes x, y and z (not shown).
  • N > 2N-sided polygon N > 2N-sided polygon
  • said transversal row has a curved surface aligned with the 180° arc segment of said circle.
  • the spatially distributed X-ray microsources MS contained in said further multi-source radiator array RA 2 are consecutively placed along the entire length of a longitudinal column parallel to the aforementioned longitudinal symmetry axis z of the substantial cylindrical gantry opening 105. Due to the programmable switching option of the sequentially switchable X-ray microsources MS, the projections from all source positions can be acquired very fast. This is the necessary precondition for a reconstruction without motion artefacts but with high temporal resolution. As an alternative to this setup geometry, it may be foreseen that the employed flat panel detectors depicted in Fig.
  • 5f may be replaced with at least one detector array DA comprising a number of spatially distributed X-ray detectors D or small detector modules consecutively arranged at adjacent angular positions along at least one perimetral edge of the 2N-sided polygon or along at least one arc segment of said circle such as in a standard rotational CT scanner setup.
  • detector array DA comprising a number of spatially distributed X-ray detectors D or small detector modules consecutively arranged at adjacent angular positions along at least one perimetral edge of the 2N-sided polygon or along at least one arc segment of said circle such as in a standard rotational CT scanner setup.
  • FIG. 6 A flow chart for illustrating the proposed method for operating a computed tomography scanner apparatus as described above with reference to said fourth or fifth exemplary embodiment, respectively, is shown in Fig. 6.
  • a switching command power-on signal
  • a switching frequency s HT which is chosen such that ⁇ yquist-Shannon's sampling theorem is fulfilled when imaging a moving object O so as to reconstruct said
  • the advantageous effect of the present invention is to enhance the both temporal and spatial resolution for a 3D image reconstruction, the latter effect being achieved by optimizing the alignment of the radiator and detector arrays.
  • the angular positioning of the individual X-ray detectors is optimized.
  • the use of smaller X-ray detectors is beneficial as the costs for these smaller chips are lower, which is due to a better yield and due to the possibility of a mass production.
  • the flexibility of the placement and the reduced distance for the X-ray beam from source to detector is also beneficial for this application compared to large detector setups.
  • the present invention and the above exemplary embodiments can be used in the scope of stationary CT or microtomography systems that are equipped with spatially distributed X-ray sources of the cone-beam type.
  • the invention can especially be applied in small animal imaging or other high-speed medical image acquisition and image processing scenarios where it is beneficial to generate two- or three-dimensionally reconstructed high- resolution images of fast moving objects (such as e.g. the myocard) at an image acquisition rate which is high enough to fulfill Shannon-Nyquist's sampling theorem so as to avoid disturbing motion or aliasing artifacts and thus to improve the obtained image quality.
  • CT imaging systems having a stationary X-ray detector and a plurality of stationary X-ray microsources, each capable of projecting a directed X-ray beam (not necessarily all at once)
  • the benefits of the invention described herein may accrue to imaging modalities other than CT.
  • additional, although the herein described method and apparatus are described as belonging to a medical setting, it is contemplated that the benefits of the invention accrue to non-medical imaging systems such as those systems typically employed in an industrial setting or a transportation setting, such as, for example, but not limited to, a baggage scanning system for an airport or any other kind of transportation center.
  • a computer program may be stored/distributed on a suitable medium, such as e.g. an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as e.g. via the Internet or other wired or wireless telecommunication systems.
  • a suitable medium such as e.g. an optical storage medium or a solid-state medium supplied together with or as part of other hardware, but may also be distributed in other forms, such as e.g. via the Internet or other wired or wireless telecommunication systems.

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Abstract

Système d'imagerie basé sur une tomodensimétrie (CT) à sources de rayons X réparties et, plus particulièrement, scanner à tomosensimétrie et procédé d'acquisition d'images par tomodensimétrie et reconstruction 3D au moyen de géométries d'agencement à détecteurs de sources stationnaires, partiellement stationnaires ou non stationnaires avec au moins un anneau de détection fixé à demeure à une potence (101) et un certain nombre d'ensembles rayonnants contigus ou partiellement continus (RA1, RA2, …, RA N ) comprenant chacun un certain nombre de microsources de rayons X (R, MS) du type faisceau conique réparties dans l'espace, de préférence fabriquées selon la technologie des nanotubes de carbone. Ce dispositif autorise des taux d'échantillonnage plus élevés pour une résolution temporelle améliorée des images de CT acquises, comme requis pour une reconstruction exacte d'objets à mouvements rapides (tels que le myocarde)à partir d'un ensemble de données de projection acquises. Dans des modes de réalisation fournis à titre d'exemple sont décrits divers agencements d'ensembles d'éléments rayonnants ou de sources de type CNT (RA1, RA2, …, RA N ) et d'ensembles détecteurs (DA1, DA2, …, DA N ) qui, compte tenu des contraintes d'échantillonnage améliorées susmentionnées, permettent d'améliorer la résolution spatiale des images reconstruites grâce à une réduction d'artéfacts attribuables à des données d'acquisition d'images manquantes ou partiellement disponibles.
PCT/IB2009/051083 2008-03-21 2009-03-17 Dispositif de tomodensimétrie et procédé d'acquisition d'images par tomodensimétrie basés sur des microsources de rayons x réparties dans l'espace du type faisceau conique Ceased WO2009115982A1 (fr)

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Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102551783A (zh) * 2012-02-16 2012-07-11 邓敏 手术用双模态实时成像装置、系统及其方法
CN102697518A (zh) * 2012-06-25 2012-10-03 苏州生物医学工程技术研究所 静态能量分辨ct扫描仪及其扫描方法
JP2013085965A (ja) * 2011-10-19 2013-05-13 Toshiba Corp 円軌道コーンビームコンピュータ断層撮影（ｃｔ）においてアーチファクトを大幅に軽減するための方法およびシステム
WO2014028930A1 (fr) * 2012-08-17 2014-02-20 The University Of North Carolina At Chapel Hill Systèmes de tomographie assistée par ordinateur à portique immobile et procédés ayant des réseaux de sources de rayons x répartis
WO2014047518A1 (fr) * 2012-09-20 2014-03-27 Virginia Tech Intellectual Properties, Inc. Tomodensitométrie à source stationnaire et systèmes de tdm-irm
CN103760180A (zh) * 2014-01-27 2014-04-30 东南大学 基于x射线源阵列的实时在线工业ct检测系统
WO2014101284A1 (fr) * 2012-12-31 2014-07-03 同方威视技术股份有限公司 Dispositif d'inspection d'article utilisant une source de rayons x distribuée
US8971484B2 (en) 2011-11-22 2015-03-03 Xinray Systems Inc High speed, small footprint x-ray tomography inspection systems, devices, and methods
CN104434163A (zh) * 2014-12-05 2015-03-25 中国科学院深圳先进技术研究院 一种碳纳米ct成像系统及成像方法
WO2015119466A1 (fr) * 2014-02-07 2015-08-13 주식회사 바텍 Dispositif d'imagerie à rayons x
WO2016034073A1 (fr) * 2014-09-02 2016-03-10 同方威视技术股份有限公司 Appareil d'inspection automatique par rayons x de la qualité d'un produit
US9490099B2 (en) 2014-08-20 2016-11-08 Wisconsin Alumni Research Foundation System and method for multi-source X-ray-based imaging
WO2017001569A1 (fr) * 2015-06-30 2017-01-05 Alfred Fuchs Procédé et dispositif de codage d'angles d'éventail de rayons x partiels d'un rayonnement x en éventail dans les rayons x partiels
KR20170060453A (ko) * 2015-11-24 2017-06-01 주식회사바텍 복수의 엑스선 소스와 센서를 구비한 엑스선 촬영장치
US9901311B2 (en) 2013-06-26 2018-02-27 Koninklijke Philips N.V. Imaging apparatus
CN108013885A (zh) * 2016-10-31 2018-05-11 株式会社岛津制作所 放射线透视装置
WO2018086744A3 (fr) * 2016-11-12 2018-08-30 Vilicus 142 Gmbh Tomographe assisté par ordinateur
CN109738465A (zh) * 2019-03-07 2019-05-10 北京航星机器制造有限公司 一种ct探测装置及系统
US10463317B2 (en) 2015-10-01 2019-11-05 Duke University Systems and methods for estimating irradiation dose for patient application based on a radiation field model and a patient anatomy model
CN113133772A (zh) * 2020-01-20 2021-07-20 上海交通大学 Pet-ct系统及扫描方法
WO2022058036A1 (fr) * 2020-09-19 2022-03-24 Esspen Gmbh Machine de tomographie assistée par ordinateur et procédé de fonctionnement d'une machine de tomographie assistée par ordinateur
US20230346328A1 (en) * 2020-06-25 2023-11-02 Australian Lung Health Initiative Pty Ltd Imaging device and method for multiple image acquisition
EP3685419B1 (fr) * 2017-09-21 2025-02-26 Esspen GmbH Appareil de radiographie à bras en c
WO2025244676A1 (fr) * 2024-05-20 2025-11-27 Medichord Llc Système de tomodensitomètre à grande vitesse avec tube à rayons x produisant des sources de rayons x linéaires

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004000356A (ja) * 2002-06-03 2004-01-08 Hitachi Medical Corp マルチスライスｘ線ｃｔ装置および方法
US20050135550A1 (en) * 2003-12-23 2005-06-23 Man Bruno D. Method and apparatus for employing multiple axial-sources
WO2005104952A1 (fr) * 2004-04-28 2005-11-10 Philips Intellectual Property & Standards Gmbh Tomographie par ordinateur tridimensionnelle par faisceau d'electrons

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004000356A (ja) * 2002-06-03 2004-01-08 Hitachi Medical Corp マルチスライスｘ線ｃｔ装置および方法
US20050135550A1 (en) * 2003-12-23 2005-06-23 Man Bruno D. Method and apparatus for employing multiple axial-sources
WO2005104952A1 (fr) * 2004-04-28 2005-11-10 Philips Intellectual Property & Standards Gmbh Tomographie par ordinateur tridimensionnelle par faisceau d'electrons

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
ENZHUO QUAN ET AL: "EVALUATION OF HEXAGONAL AND SQUARE GEOMETRIES FOR MOTION-FREE ARRAYED-SOURCE X-RAY MICRO-CT", BIOMEDICAL IMAGING: FROM NANO TO MACRO, 2007. ISBI 2007. 4TH IEEE INTE RNATIONAL SYMPOSIUM ON, IEEE, PI, 1 April 2007 (2007-04-01), pages 221 - 224, XP031084250, ISBN: 978-1-4244-0671-5 *

Cited By (44)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013085965A (ja) * 2011-10-19 2013-05-13 Toshiba Corp 円軌道コーンビームコンピュータ断層撮影（ｃｔ）においてアーチファクトを大幅に軽減するための方法およびシステム
US8971484B2 (en) 2011-11-22 2015-03-03 Xinray Systems Inc High speed, small footprint x-ray tomography inspection systems, devices, and methods
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WO2014047518A1 (fr) * 2012-09-20 2014-03-27 Virginia Tech Intellectual Properties, Inc. Tomodensitométrie à source stationnaire et systèmes de tdm-irm
US11534122B2 (en) 2012-09-20 2022-12-27 Virginia Tech Intellectual Properties, Inc. Stationary source computed tomography and CT-MRI systems
US9341736B2 (en) 2012-12-31 2016-05-17 Tsinghua University Goods inspection apparatus using distributed X-ray source
WO2014101284A1 (fr) * 2012-12-31 2014-07-03 同方威视技术股份有限公司 Dispositif d'inspection d'article utilisant une source de rayons x distribuée
EP2940456A4 (fr) * 2012-12-31 2016-12-07 Nuctech Co Ltd Dispositif d'inspection d'article utilisant une source de rayons x distribuée
US9901311B2 (en) 2013-06-26 2018-02-27 Koninklijke Philips N.V. Imaging apparatus
CN103760180B (zh) * 2014-01-27 2016-09-07 东南大学 基于x射线源阵列的实时在线工业ct检测系统
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US10165993B2 (en) 2014-02-07 2019-01-01 Vatech Co., Ltd. X-ray imagin device with distributed X-ray source
EP3103394A4 (fr) * 2014-02-07 2017-12-20 Vatech Co. Ltd. Dispositif d'imagerie à rayons x
WO2015119466A1 (fr) * 2014-02-07 2015-08-13 주식회사 바텍 Dispositif d'imagerie à rayons x
US9490099B2 (en) 2014-08-20 2016-11-08 Wisconsin Alumni Research Foundation System and method for multi-source X-ray-based imaging
US9934932B2 (en) 2014-08-20 2018-04-03 Wisconsin Alumni Research Foundation System and method for multi-source X-ray-based imaging
WO2016034073A1 (fr) * 2014-09-02 2016-03-10 同方威视技术股份有限公司 Appareil d'inspection automatique par rayons x de la qualité d'un produit
US10969346B2 (en) 2014-09-02 2021-04-06 Nuctech Company Limited X-ray product quality automatic inspection device
CN104434163A (zh) * 2014-12-05 2015-03-25 中国科学院深圳先进技术研究院 一种碳纳米ct成像系统及成像方法
WO2017001569A1 (fr) * 2015-06-30 2017-01-05 Alfred Fuchs Procédé et dispositif de codage d'angles d'éventail de rayons x partiels d'un rayonnement x en éventail dans les rayons x partiels
US10463317B2 (en) 2015-10-01 2019-11-05 Duke University Systems and methods for estimating irradiation dose for patient application based on a radiation field model and a patient anatomy model
WO2017090992A1 (fr) * 2015-11-24 2017-06-01 주식회사 바텍 Dispositif de capture d'images radiologiques ayant une pluralité de sources et capteurs de rayons x
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WO2018086744A3 (fr) * 2016-11-12 2018-08-30 Vilicus 142 Gmbh Tomographe assisté par ordinateur
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US10849575B2 (en) 2016-11-12 2020-12-01 Esspen Gmbh Computer tomograph
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