Abstract: A grid 3 arranged with a scattered radiation shielding plate 31 for each column is arranged at a front face of a radiation detector 2. The distance between the grid 3 and the radiation detector 2 is desirably a integral multiple of the height of the scattered radiation shielding plate 31. A true image signal of the pixel column including the shade is estimated from the image signal of the pixel column adjacent to the pixel column including the shade 41. The scattered radiation distribution is estimated from the image signals of the pixel column including the shade of the scattered radiation shielding plate and the image signals when considering that the shielding plate is not included in the shielded pixel. A clear diagnosis image without influence of scattered radiation is obtained by subtracting the estimated scattered radiation distribution from the estimated image signal distribution.

Abstract: A general imaging scheme is proposed for applications of CBCT. The approach provides a superior CBCT image quality by effective scatter correction and noise reduction. Specifically, in its implementation of CBCT imaging for radiation therapy, the proposed approach achieves an accurate patient setup using a partially blocked CBCT with a significantly reduced radiation dose. The image quality improvement due to the proposed scatter correction and noise reduction also makes CBCT-based dose calculation a viable solution to adaptive treatment planning.

Abstract: Computed tomography (CT) systems and related methods involving post-target collimation are provided are provided. In this regard, a representative method involving post-target collimation of X-rays includes: emitting X-rays toward a target; and collimating the X-rays downstream of the target.

Abstract: Known reconstruction techniques from coherent scattered x-rays apply non-exact reconstruction techniques. According to the present invention, a relatively wide spectrum of wave-vector transfers q of the scattered x-ray photons is acquired. The projection data is interpreted as line integrals in the x y-q space and the projection data is resorted to correspond to an acquisition along any source trajectory. Due to this, an exact helical reconstruction algorithms may be applied and redundant data may be used to obtain a better image quality.

Abstract: In one aspect, A method of imaging an object of interest positioned in an exposure area is provided. The method comprises obtaining projection data of the object by providing radiation to the exposure area and detecting at least some of the radiation exiting the object to form the projection data, performing a first reconstruction of the projection data to form at least one bootstrap image, obtaining first data based on information provided by the at least one bootstrap image, and performing a second reconstruction of the projection data based, at least in part, on the first data to form at least one second image.

Abstract: Scatter effects are reduced in a radiographic imaging device, such as a digital slot scan mammographic imaging device, by reducing detected scatter and processing detector information to compensate for scatter effects. In one embodiment, a digital mammographic imaging system (10) includes a source (24) for transmitting a narrow beam (28) and a detector assembly (32) for detecting the beam (28). The beam (28) and the detector assembly (32) are synchronously scanned across the patient's breast (48) to obtain an image. Collimator slats (74) are provided at the leading and trailing edges of the detector to reduce detected scatter. Additionally, attenuators (76 and 92) are provided at the ends of the scanned motion and at the anterior edge of the detector array to assist in determining a spatial intensity profile.

Abstract: Scatter compensation is achieved in an X-ray imaging system by providing collimation means in the form of shutters (12) to collimate the primary X-ray beam (1) such that the radiation (8) transmitted through a subject (4) to be imaged is incident substantially centrally on the active part (14) of an image detector (3), so as to define an active border (14b), in respect of which scatter levels can be measured. An electrical signal (104) representative of the scatter level is subtracted from the electrical signal (7) representative of the radiation (8) transmitted through the subject, to obtain a scatter-compensated image signal (106).

Abstract: An X-ray CT apparatus includes X-ray tubes, slit mechanisms which are respectively provided for X-ray tubes and whose slit widths can be changed, two-dimensional array type X-ray detectors which form pairs with the X-ray tubes, a support mechanism which supports the X-ray tubes and the X-ray detectors so as to allow them to rotate about a rotation axis parallel to the slice direction, a correction unit which corrects data from each detection element located in an area which X-rays passing through the slit mechanism directly strike, by using data from at least one detection element located outside the area and associated with the same channel in order to reduce a scattered radiation component originating from X-rays generated by an X-ray tube other than the X-ray tube forming the pair, and a reconstruction unit which reconstructs image data on the basis of the corrected data.

Abstract: An X-ray CT apparatus includes a plurality of X-ray tubes, a plurality of X-ray detectors corresponding to the plurality of X-ray tubes, respectively, a support mechanism which supports the X-ray tubes and the X-ray detectors to allow the X-ray tubes and the X-ray detectors to rotate about a single rotation axis, a reconstruction unit which reconstructs image data on the basis of outputs from the X-ray detectors, and a plurality of filters which are respectively provided for the plurality of X-ray tubes and each have a characteristic in which an X-ray path length changes along a curve approximate to an inverted Gaussian curve from the rotation center to the two ends of an X-ray beam.

Abstract: A Digital Radiograph (DR) acquisition system for generating a scatter-corrected X-ray image is provided. The DR acquisition system includes a digital detector configured to produce a two-dimensional (2D) X-ray image of an object of interest. The digital detector is configured to detect X-rays emitted from an X-ray source and transmit the X-rays through the object of interest and generate the 2D X-ray image in response to the detected X-rays. The DR acquisition system further includes an image processor coupled to the digital detector, and a display unit. The image processor is configured to generate projection image data from the 2D X-ray image and iteratively reconstruct the 2D X-ray image to generate a scatter-corrected X-ray image based on the generated projection image data. The display unit configured to display the scatter-corrected X-ray image in conjunction with the 2D X-ray image.

Abstract: A method for estimating a scattered ray intensity distribution in an X-ray CT apparatus, the method includes: irradiating a subject with X-rays; and configuring a cross-sectional image of the subject by detecting the X-rays passing through the subject, on the basis of a path length of a scattered ray passing through the subject, an X-ray absorption coefficient of the subject and an X-ray scattering probability of the subject, intensity of the scattered ray being calculated.

Abstract: Due to the provision of slit collimators an intensity of a fan beam is reduced significantly such that expensive high power x-ray tubes have to be used. According to an exemplary embodiment of the present invention, a high power tube may be used with a very long focus in combination with a focusing collimator. The tube can be a cheap fixed anode tube still with a high power of, for example, 15 kW due to the large focus. The collimator may ensure that the resolution of the reconstructed scatter function is not degraded. The illuminated slice thickness is increased which may allow for an isotropic spatial resolution.

Abstract: The radiation scattered in a two-dimensional detector (2) by a radiation is estimated by subjecting the detector (2) to at least two irradiations by inserting an array (3) of separated absorbers placed at variable distances (L) from the detector (2), measuring the (scattered) radiation at the shadow spots (6) of the absorbers and interpolating elsewhere to provide continuous images of the scattered radiation, and by deducing parameters modelling a scattered radiation distribution function in the detector.

Abstract: The invention relates to a method, to an X-ray apparatus for performing the method and to a detector arrangement intended for the latter, for producing X-ray images containing a reduced proportion of scattered radiation. The X-ray radiation is detected in this case by a detector arrangement comprising two X-ray detectors, there being provided in the first X-ray detector openings through which the second X-ray detector is able to detect scattered radiation and primary radiation by separate detector elements. The signals given by the second X-ray detector are used to determine the proportion of scattered radiation that is contained in the image produced by the first X-ray detector and to largely free the first image of the proportion of scattered radiation.

Abstract: A detector module, in at least one embodiment, is disclosed for x-radiation or gamma radiation that includes one or more optical waveguide sections that are arranged next to one another in order to form one or more detector rows and are optically interconnected in serial fashion. The waveguide sections include one or more converter materials for converting incident x-radiation or gamma radiation into optical radiation and are designed in such a way that optical radiation of different wavelength is generated in respectively neighboring regions along the waveguide sections upon incidence of x-radiation or gamma radiation. The present detector module, in at least one embodiment, can be implemented cost effectively with a high number of detector rows, and is of very low weight.

Abstract: An imaging system for generating a diffraction profile is described. The imaging system includes a gantry including an x-ray imaging system configured to generate an x-ray image of a substance and a scatter system configured to generate a diffraction profile of the substance.

Abstract: A system may include emission of megavoltage radiation from a megavoltage radiation source, acquisition of a first image using an imaging device while first megavoltage radiation is emitted from the megavoltage radiation source and while a plurality of elements is between the megavoltage radiation source and the imaging device, and determination of an amount of scatter radiation based at least on areas of the acquired image corresponding to the plurality of elements. In some aspects, at least one of the plurality of elements is substantially pointed toward a focal spot of the megavoltage radiation source.

Abstract: The invention relates to a computer tomograph and to a radiation detector for detecting elastically scattered rays. The computer tomograph comprises a radiation source for radiating primary radiation through an object which is present in an examination region. The primary radiation is partly scattered in the object owing to interactions with the object. A detector comprises detector elements by which the scattered rays are detected. These detector elements lie outside the region through which the primary radiation is passed, and their effective dimensions become smaller in the direction in which the scattering angles become smaller.

Abstract: The invention relates to a computed tomography apparatus (CT apparatus) for imaging by means of radiation having traversed an object to be examined (that is, directly transmitted radiation), as well as by means of radiation scattered by the object to be examined, which apparatus includes a radiation source (S), a detector arrangement (16) and a device whereby the radiation (41a) having traversed the object to be examined can be blocked at least to an extent that the intensity incident on the detector arrangement (16) does not substantially exceed the intensity of radiation (41b) scattered by the object (13) to be examined and incident on the detector arrangement (16). The invention enables the detection of scattered radiation (CSCT mode) which is not affected by crosstalk from the transmitted radiation, even when the detector arrangement does not satisfy severe requirements as regards crosstalk properties and/or is configured as a single-row detector arrangement.

Abstract: The method is analytical, involves a single irradiation of the object at a plurality of incidences in order to obtain a first three-dimensional image of the total radiation received by the detector, but a double irradiation of a set of calibration phantoms, such as planar plates, in order to obtain their images of the total radiation and the scattered radiation. The three-dimensional image serves only to precisely evaluate, for each projection of the radiation through the object, the equivalent length of the material of the phantoms in order to obtain a similar scattered radiation. In a known manner, a ratio of scattered radiation layers is then calculated for the object and the phantoms according to the total radiation that they have received, and the scattered radiation of the object is obtained by the radiation scattered by the phantoms, which have been measured, and the ratio.

Abstract: A device and a method for computer tomography are described, in which an uncorrected volume image and a correction volume image are overlaid by the user after selection of a weighting function. This enables manual correction to be undertaken even after the correction of interference effects, such as x-ray scattering or beam hardening.

Abstract: Scatter radiation in an x-ray imaging system including an x-ray source and an x-ray detector is separated by using amplitude modulation to translate the spatial frequency of a detected x-ray beam to a higher frequency and provide separation from low frequency scatter signal. The low frequency content of the detected x-ray beam is then obtained by demodulating the detected modulated signal.

Abstract: It is proposed to estimate the scattered radiation on the basis of a sinogram, which is measured in any case. In at least one embodiment, a method includes determining the potential scattering site for each measuring beam from the object tangents in the sinogram and calculating the scattered intensity from the primary radiation striking the scattering site and the angle ratios of scattering beam, object tangent and measuring beam. Also proposed, in at least one embodiment, is an X-ray CT having at least bifocal detector systems and a control and computer unit for producing tomographic pictures, the control and arithmetic unit of which contains a program code that, upon being executed, carries out the method.

Abstract: A method for scattered radiation correction of a CT system, including at least two focus/detector systems operated angularly offset from one another, is disclosed. In the method, at at least one phantom, similar to the examined object at least in a subregion, for at least one of the focus/detector systems, the scattered radiation intensity occurring is determined in the detector of a focus/detector system during the operation of the at least one focus of at least one other focus/detector system. Further, the spatial distribution thereof is stored for a number of angles of rotation of the focus/detector systems. During scanning of the object, the scattered radiation intensities, determined with the aid of a similar phantom that originate from the at least one other focus/detector system, are subtracted from the measured intensities of the first focus/detector system while taking account of the spatial orientation of the focus/detector systems and the beam respectively considered.

Abstract: A method is disclosed for scattered radiation correction in x-ray imaging devices having a number of x-ray sources that can be moved around an examination object in at least one scanning plane during a measurement pass. During the measurement pass, a number of x-ray projections are recorded at different projection angles with simultaneous use of the x-ray sources. In at least one embodiment of the present method, parameters characterizing an outer object contour are determined in the scanning plane from measured data of different x-ray projections.

Abstract: According to an aspect of the present invention, a correction of X-ray intensities measured in an energy-resolved diffraction method may be provided for multiple scattered radiation without any assumptions on the geometry of the object examined. According to an exemplary embodiment of the present invention, the characteristic lines of the anode material in the primary spectrum are evaluated, resulting in a component analysis of the detected spectrum which may allow for a correction for its multiple scatter part.

Abstract: Cone-beam CT scanners with large detector arrays suffer from increased scatter radiation. This radiation may cause severe image artefacts. An examination apparatus is provided which directly measures the scatter radiation and uses this measurement for a correction of the contaminated image data. The measurement is performed by utilizing a 1-dimensional anti-scatter-grid and an X-ray tube with an electronic focal spot movement. Image data is detected at a first position of a focal spot and scatter data is detected at a second position of the focal spot. The image data is corrected on the basis of the scatter data.

Abstract: An apparatus for improving the tomographic image quality by preventing the tomographic image contrast from degrading and preventing artifact from occurring even if many scattered radiations occur. An X-ray detection array obtains first detection data using the X-ray detection elements corresponding to an area not shielded by a collimator. Further, the X-ray detection array obtains second detection data using the X-ray detection elements corresponding to an area shielded by the collimator. A central processing unit corrects the first detection data based on the detection data including the first and second detection data. Finally, the central processing unit generates a tomographic image for an imaging area of the imaging object.

Abstract: A CT detector includes a plurality of metallized anodes with each metallized anode separated from another metallized anode by a gap. A direct conversion material is electrically coupled to the plurality of metallized anodes and has a charge sharing region in which an electrical charge generated by an x-ray impinging the direct conversion material is shared between at least two of the plurality of metallized anodes. An x-ray attenuating material is positioned to attenuate x-rays directed toward the charge sharing region.

Abstract: A method, system, and machine readable media are provided for correcting scatter in an image. The method comprises sequentially emitting radiation from a subset of radiation sources toward a detector array and measuring radiation on areas of the detector array not exposed to the emitted primary radiation at the time of measurement. Scatter is estimated from the measured radiation. Furthermore, the scatter estimates are subtracted from the measured data and images with improved image quality are reconstructed.

Abstract: A radiation computed tomography apparatus that includes a radiation detector having a plurality of radiation detector elements arranged in a two-dimensional manner for detecting radiation passing through a subject, and a reconstructing device for arithmetically reconstructing tomographic image data for a tomographic image of the subject based on projection data for the subject from each of the plurality of radiation detector elements, the projection data obtained from values detected by the plurality of radiation detector elements, wherein the reconstructing device corrects the projection data for each of the radiation detector elements using a corrective value that is correlated with a path length of the radiation through the subject calculated from the projection data, and generates the tomographic image data based on the corrected projection data.

Abstract: Various configurations for scatter reduction and control are provided for CT imaging. These configurations include an imaging system having a stationary detector extending generally around a portion of an imaging volume and a distributed X-ray source placed proximal to the stationary detector for radiating an X-ray beam toward the stationary detector. A scatter control system is further provided that is configured to adaptively operate in cooperation with the stationary detector and the distributed X-ray source to focally align collimator septa contained therein to the X-ray beam at a given focal point and to provide X-ray beam scatter control.

Abstract: A tomosynthesis image is generated by applying preprocessing to each image obtained by capturing a plurality of X-ray images at a plurality of X-ray tube positions and then performing filtering processing and backprojection. At this time, a proper filter coefficient used filtering is determined for each scan track, each image frame, and each pixel position in an image.

Abstract: A two dimensional (2D) collimator assembly and a detector system employing a 2D collimator assembly. More specifically, a collimator assembly is provided, having elements extending in the x and z-planes of a detector system. The 2D collimator assembly includes a number of blades arranged in parallel. Each of the blades includes fins extending from one or both sides of the body of the blade. The fins are coupled to each adjacent array to form the 2D collimator assembly.

Abstract: Scatter effects are reduced in a radiographic imaging device, such as a digital slot scan mammographic imaging device, by reducing detected scatter and processing detector information to compensate for scatter effects. In one embodiment, a digital mammographic imaging system (10) includes a source (24) for transmitting a narrow beam (28) and a detector assembly (32) for detecting the beam (28). The beam (28) and the detector assembly (32) are synchronously scanned across the patient's breast (48) to obtain an image. Collimator slats (74) are provided at the leading and trailing edges of the detector to reduce detected scatter. Additionally, attenuators (76 and 92) are provided at the ends of the scanned motion and at the anterior edge of the detector array to assist in determining a spatial intensity profile.

Abstract: A method for compensating scattering includes acquiring the projective length of non-subject entities and acquiring the projective length of an object of radiography wherein the object of radiography is radiographed with a beam thickness set to the same value as a detector thickness and the object of radiography is radiographed with the beam thickness set to a value larger than the detector thickness. An amount of scattering is calculated based on the difference between the object data from the first scan and the object data from the second scan and stored in association with the sum of projective lengths. A subject is radiographed to produce data and the projective length of the subject is calculated along with the projective length of the non-subject entities having affected the data. The amount of scattering associated with the sum of the projective length and the projective length is then determined.

Abstract: A method for correcting scatter in multi-slice imaging wherein, a projection p and a scatter correction factor R(d, do) are stored in association with each other, a projection p is determined from data D0 collected by imaging a subject with an X-ray beam with a beam thickness d using a detector with a detector thickness do, the scatter correction factor R(d, do) associated with the projection p is determined, and the data D0 is multiplied by the scatter correction factor R(d, do) to obtain scatter-corrected data D1.

Abstract: Disclosed are imaging systems, methods, and computer program products that generate estimates of scattered radiation in tomographic imaging systems, such as cone-beam computerized tomography (CBCT) systems, and the like. In an exemplary embodiment, a first group of projections is taken of an object with the radiation covering a wide band of the object, and a second group of projections is taken of the object with the radiation covering a narrower band of the object. The projections of the second group cover less of the object, but have less scattered radiation. The scattered radiation within the narrower band may be estimated from differences between projections from the first and second groups, or from representations thereof.

Abstract: A Digital Radiograph (DR) acquisition system for generating a scatter-corrected X-ray image is provided. The DR acquisition system includes a digital detector configured to produce a two-dimensional (2D) X-ray image of an object of interest. The digital detector is configured to detect X-rays emitted from an X-ray source and transmit the X-rays through the object of interest and generate the 2D X-ray image in response to the detected X-rays. The DR acquisition system further includes an image processor coupled to the digital detector, and a display unit. The image processor is configured to generate projection image data from the 2D X-ray image and iteratively reconstruct the 2D X-ray image to generate a scatter-corrected X-ray image based on the generated projection image data. The display unit configured to display the scatter-corrected X-ray image in conjunction with the 2D X-ray image.

Abstract: A computed tomography unit includes at least one X-ray tube, that scans an object in a fashion rotating in a circle or spiral about a z-axis, in combination with an oppositely situated detector having a multiplicity of detector rows. Each detector row includes an aperture ?z in the z-direction, having a multiplicity of detector elements. Between the X-ray tube and detector, a detector diaphragm is arranged that reduces the aperture ?z of the detector rows in the z-direction. The X-ray tube includes a focus, of variable location relative to the X-ray tube and which alternatingly assumes during scanning at least two different positions that have different z-coordinates relative to the X-ray tube R.

Abstract: A device (1) for computer tomography, which is set up for x-ray scatter correction, features an evaluation unit (17) which evaluates values stored as a table in a data memory for x-ray scatter correction, which have been determined in advance with the aid of a Monte Carlo simulation which take account of interactions of the photons with the object (2) to be investigated.

Abstract: A method for reconstructing an image of an object includes scanning the object with a computed tomography (CT) system to obtain data, estimating a size of the object using the obtained data, using the estimated size of the object to perform scatter correction on the obtained data, and reconstructing an image using the scatter corrected data.

Abstract: An adaptive CT data acquisition system and technique is presented whereby radiation emitted for CT data acquisition is dynamically controlled to limit exposure to those detectors of a CT detector assembly that may be particularly susceptible to saturation during a given data acquisition. The data acquisition technique recognizes that for a given subject size and position that pre-subject filtering and collimating of a radiation beam may be insufficient to completely prevent detector saturation. Therefore, the present invention includes implementation of a number of CT data correction techniques for correcting otherwise unusable data of a saturated CT detector. These data correction techniques include a nearest neighbor correction, off-centered phantom correction, off-centered synthetic data correction, scout data correction, planar radiogram correction, and a number of others.

Abstract: A system includes acquisition of a first image of a first radiation field, at least a portion of the first radiation field comprising radiation attenuated by a device, and the first image including a representation of first scatter radiation generated during acquisition of the first image, acquisition of a second image of a second radiation field, at least a portion of the second radiation field comprising radiation attenuated by a volume corresponding to the device, and the second image including a representation of second scatter radiation generated during acquisition of the second image, and modification of the second image based on the first image to compensate for the second scatter radiation.

Abstract: A CT scanner comprising a stator and a rotor having an axis of rotation mounted to the stator so that the rotor is rotatable about the axis of rotation comprising: an X-ray source mounted to the rotor, said X-ray source having a focal spot from which X-rays emanate; an X-ray detector array comprising a matrix of rows and columns of X-ray detectors; anti-scattering (AS) material for absorbing X-rays positioned between columns of the X-ray detectors; and anti-scattering (AS) material for absorbing X-rays positioned between rows of the X-ray detectors, whereby the AS material is located between every other row and/or column of detectors, respectively. Furthermore, the thickness and/or height of the foils between rows may be different from the thickness and/or height of the foils between columns.

Abstract: A method for performing scattered radiation correction. The position of a collimator and the width of a slit are adjusted so that direct radiation will fall on one of a plurality of arrays of detectors. A predetermined phantom is scanned. The scan is performed relative to each of the plurality of arrays of detectors. Based on data detected during each scan, scattered radiation correction data is produced. The produced scattered radiation correction data is used to correct projection data acquired by scanning a subject.

Abstract: A method for obtaining an X-ray image for an X-ray diagnosis apparatus including plurality of imaging systems, including: collecting first scatter data using a first X-ray detector after an X-ray is irradiated from a first X-ray tube in a first imaging system; collecting second scatter data using a second X-ray detector after an X-ray is irradiated from a second X-ray tube in a second imaging system; collecting first image data including a scatter component using X-ray detectors after an X-ray is irradiated from a third X-ray tube in the first imaging system; collecting second image data including a scatter component using X-ray detectors after an X-ray is irradiated from a fourth X-ray tube in the second imaging system; and obtaining X-ray images for the first and second imaging systems by subtracting the first and second scatter data from the first and second image data including a scatter component, respectively.

Abstract: Method of and system for adaptive scatter correction in the absence of scatter detectors in multi-energy computed tomography are provided, wherein input projection data acquired using at least two x-ray spectra for scanned objects may include a set of low energy projections and a set of high energy projections; wherein a low-pass filter of variable size is provided; the method comprises estimating the size of the low-pass filter; computing amounts of scatter; and correcting both sets of projections for scatter. The estimation of low-pass filter size comprises thresholding high energy projections into binary projections; filtering the binary projections; finding the maximum of the filtered binary projections; calculating the low-pass filter size from the found maximum. The computation of amounts of scatter comprises exponentiating input projections; low-pass filtering the exponentiated projections with the estimated filter size; computing the amounts of scatter from the filtered projections.

Abstract: A method for separating and filtering noise caused by X-ray scatter contaminations from the primary signal component of the signal produced by the detector assembly of a radiographic imaging device employs a scatter removal screen or grating disposed between the object being imaged and the detector assembly. The grating has an absorption that varies periodically for varying the intensity of the X-ray radiation passed through the grating. This variation in intensity of the X-ray radiation causes the signal produced by the detector assembly to be amplitude modulated so that the frequency of the primary signal component is shifted from noise components of the signal caused by X-ray scatter contamination allowing the noise components to be filtered from the primary signal component so that scatter induced noise may be reduced or eliminated from the signal.

Abstract: A radiation imaging device includes a radiation source which rotates around a subject to be examined and irradiates the subject with radiation, a two-dimensional detector in which a plurality of detection elements for detecting radiation from the radiation source are two-dimensionally arranged, and a grid which is placed in front of the two-dimensional detector to remove scattered radiation of the radiation. This device performs computation with respect to a subject image obtained by the two-dimensional detector by using the subject image and a gain image obtained by the two-dimensional detector, and executes removal of a grid pattern due to the grid and gain correction. The device reconstructs an image on the basis of the subject image obtained using the subject image from which a grid pattern due to the grid is removed and which is gain-corrected.