Abstract: A method for characterizing nature of a material, including: providing at least one sample of the material between an X-ray source and a detector; using the X-ray source to make N X-radiation spectra transmitted through the material, each for a time; calculating transmission function of the material as a function of energy or the detection channel; and in each of at least two energy zones, calculating the integral of the transmission function, thus forming at least a first transmission coefficient and a second transmission coefficient.

Abstract: A method correcting a measured spectrum of X radiation, according to a number of channels Nc, each channel i corresponding to an energy range between Ei and Ei+?Ei, including: determining function ?ti,j(k) determining size of temporal deviation ?t interval separating two interactions with energy Ei and Ej, stacking of which leads to a detected energy value Ek; determining, from the function ?ti,j(k), probability function Pi,j(k) that an event counted in a channel k corresponds to a stack of two interactions, respectively of energies Ei and Ej; determining, from the probability function Pi,j(k), a stack spectrum as a part of the measured spectrum that corresponds only to the stacks alone; and calculating or estimating at least a first corrected spectrum, by the difference between the measured spectrum and the stack spectrum.

Abstract: A method for estimating the effective atomic number of a material from a transmission spectrum of said material in which a likelihood function of the effective atomic number and the thickness of the material is calculated on the basis of the transmission spectrum as well as calibration spectra obtained in a previous calibration phase for a plurality of samples of calibration materials of known effective atomic numbers and known thicknesses. The effective atomic number of the material is then estimated on the basis of values of the likelihood function.

Abstract: A method identifying a material, includes: measuring an electromagnetic radiation spectrum emitted through the material; determining at least one measurement energy band, and spectral coefficients of a comparison function in the measurement band, using the measured spectrum; estimating, using the determined spectral coefficients, a nature and/or thickness of the material based on a set of reference spectral parameters relating to reference materials and/or thicknesses and defined in reference bands.

Abstract: A calibration method for a device for identifying materials using X-rays, including: a) determining at least one calibration material and, for each calibration material, at least one calibration thickness of this material, b) measuring, for each of the calibration materials and for each of the selected calibration thicknesses, attenuation or transmission coefficients for X radiation, c) calculating statistical parameters from the coefficients, d) determining or calculating, for each calibration material and for each calibration thickness, a presence probability distribution law, as a function of the statistical parameters.

Abstract: The invention relates to a device for identifying a material of an object having a source of X-Ray photons and a spectrometric detector, the source irradiating the object with an incident beam and the detector measuring a magnitude of a backscattered beam from the incident beam after scattering in a volume (?V) of the material and an energy of the X-Ray photons of the backscattered beam. The incident and backscattered beams forming a scattering angle (?). An adjusting device adjusts the position between the source, the detector and the object in order for the volume to be at different depths with a constant angle. A processing device processes the two magnitudes in two positions and the energy in one position and calculates an attenuation coefficient (?material (E0, E1, ?)). An estimating device estimates the density (?) of the material.

Abstract: In various embodiments, systems and methods can provide accurate measurements of blood flow dynamics in a subject. Projection data acquired during a computed tomography (CT) scan of the subject can be used to determine information representing inflow of a contrast material. Accordingly, a measurement of flow velocity, in addition to other aspects of flow, may be obtained from the projection data.

Abstract: A method and device for spectrometry analysis and for extracting a primary diffuse spectrum from a diffusion spectrum of diffuse radiation, according to a diffusion angle, coming from a material exposed to incident radiation through a surface, that includes the application of a spectral response function organized in the form of a matrix (M), known as a correlation matrix, of which each value aij corresponds with a number of detected photons, with energy Ei, constituting the multiple diffuse radiation, when a photon is detected, with energy Ej, of the primary diffuse radiation.

Abstract: A method and device for obtaining a first radiation spectrum diffused through a material, in which the material is exposed to an incident irradiation beam emitted by a radiation source. A first radiation spectrum diffused through the material is measured by means of a main detector, arranged so that its observation field intersects the irradiation beam inside the material. At least one secondary radiation spectrum diffused through the material is measured by means of at least one secondary detector and a measurements matrix (X) is constructed starting from previously measured spectra. The measurements matrix is decomposed in two non-negative matrices, a weights matrix (A) and a spectra matrix (S), where the spectra matrix includes an estimated multiple diffuse radiation spectrum and an estimated primary diffuse radiation spectrum. The device includes a microprocessor and computer program. A computer program product for implementing the method is also provided.

Abstract: A method identifying a material, includes: measuring an electromagnetic radiation spectrum emitted through the material; determining at least one measurement energy band, and spectral coefficients of a comparison function in the measurement band, using the measured spectrum; estimating, using the determined spectral coefficients, a nature and/or thickness of the material based on a set of reference spectral parameters relating to reference materials and/or thicknesses and defined in reference bands.

Abstract: A calibration method for a device for identifying materials using X-rays, including: a) determining at least one calibration material and, for each calibration material, at least one calibration thickness of this material, b) measuring, for each of the calibration materials and for each of the selected calibration thicknesses, attenuation or transmission coefficients for X radiation, c) calculating statistical parameters from the coefficients, d) determining or calculating, for each calibration material and for each calibration thickness, a presence probability distribution law, as a function of the statistical parameters.

Abstract: A method correcting a measured spectrum of X radiation, according to a number of channels Nc, each channel i corresponding to an energy range between Ei and Ei+?Ei, including: determining function ?ti,j(k) determining size of temporal deviation ?t interval separating two interactions with energy Ei and Ej, stacking of which leads to a detected energy value Ek; determining, from the function ?ti,j(k), probability function Pi,j(k) that an event counted in a channel k corresponds to a stack of two interactions, respectively of energies Ei and Ej; determining, from the probability function Pi,j(k), a stack spectrum as a part of the measured spectrum that corresponds only to the stacks alone; and calculating or estimating at least a first corrected spectrum, by the difference between the measured spectrum and the stack spectrum.

Abstract: A method for characterising nature of a material, including: providing at least one sample of the material between an X-ray source and a detector; using the X-ray source to make N X-radiation spectra transmitted through the material, each for a time; calculating transmission function of the material as a function of energy or the detection channel; and in each of at least two energy zones, calculating the integral of the transmission function, thus forming at least a first transmission coefficient and a second transmission coefficient.

Abstract: A method and device for spectrometry analysis and for extracting a primary diffuse spectrum from a diffusion spectrum of diffuse radiation, according to a diffusion angle, coming from a material exposed to incident radiation through a surface, that includes the application of a spectral response function organized in the form of a matrix (M), known as a correlation matrix, of which each value aij corresponds with a number of detected photons, with energy Ei, constituting the multiple diffuse radiation, when a photon is detected, with energy Ej, of the primary diffuse radiation.

Abstract: A device for identifying a material of an object including: a source of X photons, and a spectrometric detector, the source irradiating the object with an incident beam and the detector measuring a magnitude of a backscattered beam from the incident beam after scattering in a volume of the material and an energy of the X photons of the backscattered beam, the incident and backscattered beams forming a scattering angle. Further, a mechanism adjusts position between the source, the detector, and the object for volume to be at different depths with a constant angle, and a mechanism processes the two magnitudes in two positions and the energy in one position to calculate an attenuation coefficient for estimating the density of the material.

Abstract: In various embodiments, systems and methods can provide accurate measurements of blood flow dynamics in a subject. Projection data acquired during a computed tomography (CT) scan of the subject can be used to determine information representing inflow of a contrast material. Accordingly, a measurement of flow velocity, in addition to other aspects of flow, may be obtained from the projection data.

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 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: 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 (2), 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 (5) through the object (8), 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: 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.