Abstract: A method for obtaining data includes acquiring Computed Tomography (CT) scout data at a Z location with a first x-ray spectrum, and acquiring CT scout data at the Z with a second x-ray spectrum different from the first x-ray spectrum.

Abstract: A method including detecting components of plaque using a multi-energy computed tomography (MECT) system is provided.

Abstract: A system for generating images by using monochromatic x-rays is described. The system includes an accelerator configured to increase energy of an electron beam, at least one detector element configured to receive x-rays having multiple energies generated by interaction of the electron beam with at least one laser beam, and an image reconstructor configured to reconstruct at least one image by processing the x-rays.

Abstract: A method or apparatus for analyzing an object includes an X-ray prescanner that performs a prescan of the object to determine prescan information about the object. Then, a CT scanner performs a CT scan on at least one plane of the object based on the prescan information to determine CT information. In one embodiment, if the CT scan of the object includes or is in the vicinity of metal, then metal artifact correction of a reconstructed image from the CT scan is performed based on the prescan information.

Abstract: A method for obtaining data includes quantifying tissue fat content using a multi-energy computed tomography (MECT) system.

Abstract: A method for analyzing materials in an object includes acquiring x-ray projection data of the object at high energy and at low energy for a plurality of views. The acquired x-ray projection data is utilized in a material decomposition to determine material densities at each pixel for two selected basis materials. A composition of an object at each pixel is determined utilizing a determined mapping of material density regions for the two selected basis materials. An image indicative of the composition of the object is displayed utilizing the determined composition.

Abstract: A multispectral X-ray imaging system uses a wideband source and filtration assembly to select for M sets of spectral data. Spectral characteristics may be dynamically adjusted in synchrony with scan excursions where an X-ray source, detector array, or body may be moved relative to one another in acquiring T sets of measurement data. The system may be used in projection imaging and/or CT imaging. Processed image data, such as a CT reconstructed image, may be decomposed onto basis functions for analytical processing of multispectral image data to facilitate computer assisted diagnostics. The system may perform this diagnostic function in medical applications and/or security applications.

Abstract: A conveying section conveys an inspected object so as to cross the X-rays irradiated from an X-ray generating section. A first sensor module is disposed along a transmitting direction of the X-rays transmitted through the inspected object, and receives one portion of the X-rays transmitted through the inspected object, and outputs a first electric signal corresponding to a first X-ray energy amount. A second sensor module receives a remaining portion of the X-rays transmitted through the inspected object, and outputs a second electric signal corresponding to a second X-ray energy amount different from the first X-ray energy amount. Presence/absence of a foreign material mixed in the inspected object can be detected based on the first and second electric signals, which are output from the first and second sensor modules to the same inspected object at substantially the same detection time.

Abstract: The present invention is directed to a method and apparatus for CT data acquisition using a rotatable pre-subject filter having more than one filtering profile to control radiation exposure to a subject. The filter is caused to rotate by a motor and bearing assembly and has one profile used to filter radiation when the radiation source is positioned above a subject and another profile that is used to filter radiation when the radiation source is positioned at a side of the subject.

Abstract: A multispectral X-ray imaging system uses a wideband source and filtration assembly to select for M sets of spectral data. Spectral characteristics may be dynamically adjusted in synchrony with scan excursions where an X-ray source, detector array, or body may be moved relative to one another in acquiring T sets of measurement data. The system may be used in projection imaging and/or CT imaging. Processed image data, such as a CT reconstructed image, may be decomposed onto basis functions for analytical processing of multispectral image data to facilitate computer assisted diagnostics. The system may perform this diagnostic function in medical applications and/or security applications.

Abstract: A method or apparatus for analyzing an object includes an X-ray prescanner that performs a prescan of the object to determine prescan information about the object. Then, a CT scanner performs a CT scan on at least one plane of the object based on the prescan information to determine CT information. In one embodiment, if the CT scan of the object includes or is in the vicinity of metal, then metal artifact correction of a reconstructed image from the CT scan is performed based on the prescan information. In another embodiment, a processor analyzes the CT information and the prescan information to determine whether to update the prescan information based on the CT information.

Abstract: A method of and system for locating a targeted region in a patient uses a CT imaging subsystem and a radiotherapy subsystem arranged so the targeted region can be imaged with the imaging system and treated with a beam of therapeutic X-ray radiation using a radiotherapy subsystem. The beam of therapeutic X-rays is in a plane that is substantially fixed relative to, and preferably coplanar with, a slice plane of the CT imaging subsystem so that the targeted region can be imaged during a planning phase, and imaged and exposed to the therapeutic X-rays during the treatment phase without the necessity of moving the patient.

Abstract: The present technique provides for the generation of density maps using one or more basis material decomposition tables or functions. The basis material decomposition tables or functions are generated by simulating the system response to various lengths of basis materials using component characteristics of the CT system as well as the attenuation coefficient for the desired basis material. Measured projection data may be processed using the basis material decomposition tables or functions to provide a set of density line-integral projections that may be reconstructed to form a density map or image.

Abstract: A method for obtaining data including scanning an object using a multi-energy computed tomography (MECT) system to obtain data to generate an anatomical image, and decomposing the obtained data to generate a first density image representative of bone material and a second density image representative of soft-tissue. The method further includes segmenting at least one of the first density image and the second density image, and volume rendering the second density image.

Abstract: The invention relates to an isokinetic gantry arrangement for the isocentric guidance of a particle beam (12), that can be rotated about a horizontal longitudinal axis (16) and has a beam optical system, symbolized by magnets (36, 38, 40), that deflects the particle beam (12) axially infected by a particle beam accelerator, radially and vertically relative to the horizontal longitudinal axis (16), with a largely rotationally-symmetrical primary structure (18) and a secondary structure (30) that holds the magnets (36, 38, 40) and is supported by the primary structure (18), with the secondary structure (30) having a rigidity that is designed so that the vertical displacements of the magnets (36, 38, 40) due to their weight are essentially of equal magnitude (isokinetic) in all the angle of rotation positions of the gantry arrangement (10), and a method for its design.

Abstract: A method for obtaining perfusion data includes providing an object of interest, estimating a first quantity of contrast agent utilized by a mono-energy computed tomography (CT) imaging system to image the object of interest, introducing a second quantity of contrast agent into the object of interest, the second quantity of contrast agent less than the first quantity of contrast agent, and scanning the object of interest using a multi-energy Computed Tomography (MECT) system to acquire data.

Abstract: This radiography process utilizes dual-energy rays and comprises, in order to differentiate bone, lean and fatty tissues at the same time, an improvement consisting in assessing the total length penetrated by each ray while correcting the errors which may be produced by internal gas pockets. One proceeds as follows: selection of certain rays which have not penetrated bone tissues; calculation of the thicknesses of lean and fatty tissues penetrated by these rays according to the two attenuations, the sum of these two thicknesses being the length of attenuation; estimation of the length of attenuation elsewhere, in particular by means of interpolations; and calculation of the thicknesses of the three categories of tissues penetrated according to this total length of attenuation and the two attenuations.

Abstract: A multispectral X-ray imaging system uses a wideband source and filtration assembly to select for M sets of spectral data. Spectral characteristics may be dynamically adjusted in synchrony with scan excursions where an X-ray source, detector array, or body may be moved relative to one another in acquiring T sets of measurement data. The system may be used in projection imaging and/or CT imaging. Processed image data, such as a CT reconstructed image, may be decomposed onto basis functions for analytical processing of multispectral image data to facilitate computer assisted diagnostics. The system may perform this diagnostic function in medical applications and/or security applications.

Abstract: A multispectral X-ray imaging system uses a wideband source and filtration assembly to select for M sets of spectral data. Spectral characteristics may be dynamically adjusted in synchrony with scan excursions where an X-ray source, detector array, or body may be moved relative to one another in acquiring T sets of measurement data. The system may be used in projection imaging and/or CT imaging. Processed image data, such as a CT reconstructed image, may be decomposed onto basis functions for analytical processing of multispectral image data to facilitate computer assisted diagnostics. The system may perform this diagnostic function in medical applications and/or security applications.

Abstract: A method includes scanning myocardial tissue of a patient with an Energy Discrimination Computed Tomography (EDCT) system to acquire data, and analyzing the acquired data for at least one of cardiac measurements, diagnosis, and prognosis after interventions.

Abstract: Techniques for deriving bone properties from images generated by a dual-energy x-ray absorptiometry apparatus include receiving first image data having pixels indicating bone mineral density projected at a first angle of a plurality of projection angles. Second image data and third image data are also received. The second image data indicates bone mineral density projected at a different second angle. The third image data indicates bone mineral density projected at a third angle. The third angle is different from the first angle and the second angle. Principal moments of inertia for a bone in the subject are computed based on the first image data, the second image data and the third image data. The techniques allow high-precision, high-resolution dual-energy x-ray attenuation images to be used for computing principal moments of inertia and strength moduli of individual bones, plus risk of injury and changes in risk of injury to a patient.

Abstract: One embodiment of the invention provides a system that facilitates optical proximity correction for alternating aperture phase shifting designs. During operation, the system receives a layout, which includes a complementary mask and a phase shifting mask. A subset of trim features on the complementary mask that are designed to protect the dark areas left unexposed by the phase shifting mask are adjusted first using a rules-based optical proximity correction process. This is then supplemented by a model-based correction to the phase shifters, Additionally, the portions of the trim that are co-extensive with the original layout can be corrected, e.g. at the time of the correction of the complementary mask using either rule or model based corrections.

Abstract: A method for obtaining data includes scanning a lung of a patient with a Multi-Energy Computed Tomography (MECT) system to acquire data regarding a plurality of contrast agents.

Abstract: The present technique provides for the generation of density maps using one or more basis material decomposition tables or functions. The basis material decomposition tables or functions are generated by simulating the system response to various lengths of basis materials using component characteristics of the CT system as well as the attenuation coefficient for the desired basis material. Measured projection data may be processed using the basis material decomposition tables or functions to provide a set of density line-integral projections that may be reconstructed to form a density map or image.

Abstract: An electronic imaging apparatus includes a connecting section connected to an optical apparatus; an optical element having a preset transmittance with respect to light in a preset wavelength region, incident from the optical apparatus; and an electronic image sensor receiving the light transmitted through the optical element.

Abstract: A method or apparatus for analyzing an object includes an X-ray prescanner that performs a prescan of the object to determine prescan information about the object. Then, a CT scanner performs a CT scan on at least one plane of the object based on the prescan information to determine CT information. In one embodiment, if the CT scan of the object includes or is in the vicinity of metal, then metal artifact correction of a reconstructed image from the CT scan is performed based on the prescan information.

Abstract: An X-ray computed tomography apparatus has a beam filter arrangement with regions of different filter material or/and different thickness profile of the filter material. This beam filter arrangement is disposed in the beam path preceding an examination subject. For multi-spectra beam hardening correction with estimation of the base material lengths, the computed tomography apparatus is fashioned for implementing projections of the examination subject with different effective material thickness or/and different effective material of the beam filter arrangement.

Abstract: A method includes scanning myocardial tissue of a patient with an Energy Discrimination Computed Tomography (EDCT) system to acquire data, and analyzing the acquired data for at least one of cardiac measurements, diagnosis, and prognosis after interventions.

Abstract: A digital x-ray imaging system employs a pixelated flat panel digital x-ray detector separated by a space from a source of x-rays which is selectively switchable between first and second, different x-ray energy levels, the space accommodating a body to be subjected to x-ray irradiation and imaging. A computer controls the x-ray source to irradiate the body with the first and second energy level x-rays and produce corresponding first and second x-ray images respectively of the first and second energy levels on the detector, the computer processing the respective digital signal outputs of the detector for the first and second digital images respectively of the first and second energy levels for each pixel, in individual succession for all pixels, and selectively produces and displays a soft tissue image or a bone/calcification image.

Abstract: A method of imaging an object by generating laser pulses with a short-pulse, high-power laser. When the laser pulse strikes a conductive target, bremsstrahlung radiation is generated such that hard ballistic high-energy electrons are formed to penetrate an object. A detector on the opposite side of the object detects these electrons. Since laser pulses are used to form the hard x-rays, multiple pulses can be used to image an object in motion, such as an exploding or compressing object, by using time gated detectors. Furthermore, the laser pulses can be directed down different tubes using mirrors and filters so that each laser pulse will image a different portion of the object.

Abstract: A method for detection of ionizing radiation comprises the steps of (i) directing ionizing radiation towards an object to be examined; (ii) preventing Compton scattered radiation, preferably at least 99% of the radiation Compton scattered in said object, from being detected; and (iii) detecting ionizing radiation spatially resolved as transmitted through said object to reveal a spatially resolved density of said object, wherein said ionizing radiation is provided within a spectral range such that more, preferably much more, photons of said ionizing radiation are Compton scattered than absorbed through the photoelectric effect in said object to thereby reduce the radiation dose to said object.

Abstract: The present technique provides a variety of processing schemes for decomposing soft tissue and bone images more accurately from low and high-energy images acquired from an imaging system, such as a dual-energy digital radiography system using flat-panel technology. In particular, a pre-decomposition process is provided for spatially matching, or registering, low and high-energy images using warping registration prior to dual energy image decomposition, which creates the soft tissue and bone images. Accordingly, the pre-decomposition process reduces motion artifacts between the low and high-energy images, thereby improving image clarity of the decomposed soft tissue and bone images.

Abstract: For pulse processing spectrometers that use a fast channel to detect input pulses, a slow channel to measure the pulses' energies, pileup inspection circuitry pulses, and binning to produce an output spectrum of captured energy values, the correction technique extends the Harms method to produce an estimate <C> of the average ratio of the number of input pulses detected in the fast channel per non-piled-up pulse whose captured energy value is to be binned into the output spectrum and, for each such non-piled-up pulse, adding the value <C> to the corrected output spectrum in the bin dictated by the captured energy value. The uncorrected spectrum is formed in the traditional manner by simply adding 1 to the equivalent bin. Three techniques are disclosed for producing the estimate <C>, a running average, a bucket averaging, and a circular buffer method.

Abstract: A method of performing bone densitometry, utilizing a dual-energy method, wherein the surrounding soft tissue in the volume of interest is accurately eliminated from the transmission images by means of a calibration procedure. The method utilizes an X-ray apparatus with a two-dimensional X-ray detector so as to perform data acquisition during one run.

Abstract: A method for statistically reconstructing an X-ray computed tomography image produced by a single X-ray CT scan having a polyenergetic source spectrum and an image reconstructor which utilize a convergent statistical algorithm which explicitly accounts for the polyenergetic source spectrum are provided. First and second related statistical iterative methods for CT reconstruction based on a Poisson statistical model are described. Both methods are accelerated by the use of ordered subsets, which replace sums over the angular index of a sinogram with a series of sums over angular subsets of the sinogram. The first method is generalized to model the more realistic case of polyenergetic computed tomography (CT). The second method eliminates beam hardening artifacts seen when filtered back projection (FBP) is used without post-processing correction. The methods are superior to FBP reconstruction in terms of noise reduction.

Abstract: A preferred embodiment of the present invention provides a method and apparatus for optimized dual energy image acquisition. The system comprises a dual energy medical imaging system, a detector, a user interface, an image segmentation module, a characterization module, and a control module. The method comprises obtaining an image from a first exposure of a patient and segmenting the image into an anatomy of interest. The method further comprises characterizing the segmented anatomy in terms of a set of patient parameters and optimizing a second exposure of the segmented anatomy based upon said anatomy and the characterization of the anatomy. A resulting anatomy image is obtained from analysis of the first and second exposures.

Abstract: A preferred embodiment of the present invention provides a method and apparatus for optimized dual energy image acquisition. The system comprises a dual energy medical imaging system, a detector, a user interface, an image segmentation module, a characterization module, and a control module. The method comprises obtaining an image from a first exposure of a patient and segmenting the image into an anatomy of interest. The method further comprises characterizing the segmented anatomy in terms of a set of patient parameters and optimizing a second exposure of the segmented anatomy based upon said anatomy and the characterization of the anatomy. A resulting anatomy image is obtained from analysis of the first and second exposures.

Abstract: In one embodiment, the present invention is a method for positioning an x-ray beam on a multi-slice detector array of an imaging system in which the detector array has rows of detector elements and is configured to detect x-rays in slices along a z-axis. The method includes steps of comparing data signals representative of x-ray intensity received from different rows of detector elements and positioning the x-ray beam in accordance with a result of the comparison.

Abstract: A method for determining a suggested value for a cancellation parameter for a dual energy decomposition includes obtaining a first energy level image of internal structure, obtaining a second, lower, energy level image of the internal structure, and iteratively processing the images to determine a provisional value for the cancellation parameter. The iteration includes varying a cancellation parameter in a cancellation equation, obtaining a structure cancelled image from the first and second energy level images according to the cancellation equation, and evaluating a cancellation metric from the structure cancelled image. The provisional cancellation parameter may then be chosen (e.g., as the value that approximately minimizes a variance cancellation metric). Further iterations may be performed around the provisional cancellation parameter to refine the provisional cancellation parameter into a final cancellation parameter.

Abstract: Cone-like radiation is irradiated from each of different directions of projection to an object, and projection image signals of different energy bands are acquired with respect to the object and each of the different directions of projection. Energy subtraction processing is performed on the projection image signals of the different energy bands, which projection image signals have been acquired with respect to the same direction of projection, and an energy subtraction-processed projection image signal is thus formed with respect to each direction of projection. A three-dimensional image or a tomographic image of the object is formed from the energy subtraction-processed projection image signals, which have been formed with respect to the different directions of projection. The object image is thus formed such that a pattern of a specific structure having low contrast, such as a diseased part in the object, can be detected easily.

Abstract: A system for spectroscopic imaging of bodily tissue in which a scintillation screen and a charged coupled device (CCD) are used to accurately image selected tissue. An x-ray source generates x-rays which pass through a region of a subject's body, forming an x-ray image which reaches the scintillation screen. The scintillation screen reradiates a spatial intensity pattern corresponding to the image, the pattern being detected by a CCD sensor. The image is digitized by the sensor and processed by a controller before being stored as an electronic image. Each image is directed onto an associated respective CCD or amorphous silicon detector to generate individual electronic representations of the separate images.

Abstract: Apparatus and method for eliminating scatter effects in x-ray imaging using two-dimensional detector arrays. The apparatus consists of, in physical order, an x-ray source, a front two-dimensional x-ray detector, a beam selector, and a rear two-dimensional x-ray detector. The subject is located between the x-ray source and front detector. The beam selector prevents scatter x-rays from reaching the rear detector. The method simultaneously solves the two interdependent problems of obtaining scatter-free x-ray images and conducting dual-energy x-ray imaging with primary x-ray data. A high-resolution composite image containing primary and scatter x-ray components is read from the front detector. A low-resolution composite image is produced from the high-resolution composite image. A pair of low-resolution primary x-ray dual-energy images is read from the rear detector. Using an improved dual-energy data decomposition method, a low-resolution primary x-ray front detector image is calculated.

Abstract: A method of generating an image representing fat distributions, comprising the steps of scanning two different levels of tube voltage using a phantom containing a sample rod of a fat standard material and a plurality of sample rods with different densities of a bone mineral equivalent material, to generate two cross sectional image data; detecting the CT number of each pixel in an entire region or an objective region of the cross sectional image data as the CT number of a tissue including fat (.alpha.wf); detecting the CT number of the bone mineral equivalent material to calculate a linear regression between the CT number and the density of the bone mineral equivalent material and to define the CT number of a tissue excluding fat (.alpha.nf); detecting the CT number of the fat standard material (.alpha.ff), while detecting the CT number of a soft tissue standard material (.alpha.st), wherein individual CT numbers are applied to the equation.alpha.wf=.alpha.nf+.beta..multidot.(.alpha.ff-.alpha.st)with .beta.

Abstract: Apparatus for generating a high contrast image of a living subject includes an X-ray source capable of generating an X-ray beam having an energy between about 4 MeV and about 40 MeV, means for directing the X-ray beam generated by the X-ray source to a preselected area of the body of a living subject, and at least one scintillating detector capable of detecting photons which are generated as a result of the interaction of the X-ray beam with the body of the living subject.

Abstract: An X-ray computerized tomographic (CT) imaging apparatus which can achieve a multiple energy scanning system on a real time basis so that plural kinds of tomographic information can be obtained corresponding to plural types of energy characteristics. The X-ray CT imaging apparatus includes: an X-ray tube for irradiating an X-ray to a biological body under medical examination; a plurality of detection systems for detecting an X-ray energy transmitted through the biological body, in which the plural detection systems have different energy characteristics respectively; a data acquisition unit for acquiring respective transmission X-ray energy data of the biological body which are detected by the plural detection systems; and a reconstruction unit for reconstructing a tomographic image for the biological body in accordance with data from the data acquisition unit.

Abstract: A CT apparatus for scanning compact structures associated with a larger body uses radiation source producing a reduced field-of-view to simplify construction and reduce exposure of the larger body. Truncation artifacts in the reconstructed image caused by volume elements in the larger body imaged by the radiation beam only for projections at some angles, are reduced by acquiring two projections at two different energies and combining those projections to compensate for the attenuation of the radiation by the volume elements of the larger body.

Abstract: A CT apparatus for scanning compact structures associated with a larger body uses radiation source producing a reduced field-of-view to simplify construction and reduce exposure of the larger body. Truncation artifacts in the reconstructed image caused by volume elements in the larger body imaged by the radiation beam only for projections at some angles, are reduced by acquiring two projections at two different energies and combining those projections to compensate for the attenuation of the radiation by the volume elements of the larger body.

Abstract: A limited number of views or projections, e.g., two, are used to generated a reconstructed image of an object. In order to improve the quality of the image, terracing and smoothing functions are implemented. In addition, the reconstructed image may be divided into objects and background prior to terracing and smothing and the object and background can be reconstructed separately. Further, after the reconstructed image is generated threat and texture analyses of the reconstructed image may be performed.

Abstract: A microtomographic system (10) for generating high-resolution, three dimensional images of a specimen (16) is disclosed. The microtomograph system includes an x-ray generator (12) that produces an x-ray beam (14), a specimen holder (18) that holds the specimen in the beam, and an x-ray detector (20) that measures the attenuation of the beam through the specimen. Two projections of each view of the specimen are made with this microtomographic system. Each projection is made with a different intensity x-ray beam. After the projections of one view of the specimen are made, the specimen is rotated on the specimen holder and another set of projections are made. The projections of each view of the specimen are analyzed together to provide a quantitative indication of the phase fraction of the material comprising the specimen. The projections of the different views are combined to provide a three-dimensional image of the specimen.

Abstract: An energy window of a scintillation camera system is set to include only events which have been Compton-scattered within a slice of the body of a patient undergoing a SPECT examination. From events so acquired, a scatter image is reconstructed. The scatter image is processed to define therewithin a plurality of regions of constant attenuation coefficient. This information can be used during the normal image reconstruction process to eliminate artifacts caused by variation in attenuation coefficient.