There is provided a method for assigning an attribute to x-ray attenuation including the steps of acquiring first and second reference material equivalent path length information associated with a first range of dual-energy x-ray attenuation information, acquiring second and third reference material equivalent path length information associated with a second range of dual-energy x-ray attenuation information, and, joining the first the first dual-energy x-ray attenuation information range with the second dual-energy x-ray attenuation information range using coefficients representing dual-energy x-ray attenuation information of the second reference material to define a third dual-energy x-ray attenuation information range upon which may be imposed dual-energy x-ray attenuation values within the third dual-energy x-ray attenuation information range to determine corresponding first reference material equivalent path lengths and third reference material equivalent path lengths.

A method for assigning one of a safe and threat condition to an object includes determining density and effective atomic number values for a plurality of predetermined safe and threat objects, plotting the values in a probability map to correlate corresponding density and effective atomic number values with each of the safe and threat objects, scanning an object to provide dual-energy attenuation images representing the object, decomposing the attenuation images into dual-reference material equivalent path length images to provide reference material equivalent path lengths representing the object, converting the reference path lengths into object path lengths, determining the effective atomic number for each pixel representing the object, and, imposing the effective atomic number and the mass density of the unknown object onto the probability map to determine a probability that the object is correlated with one of the predetermined safe and threat objects.

A radiation imaging apparatus is provided. The apparatus includes an imaging unit including pixels and a control unit. Each of the pixels includes a conversion unit and a sample/hold circuit. The control unit causes the imaging unit to perform first imaging and second imaging after the first imaging to generate one energy subtraction image, and controls a timing of causing the sample/hold circuit in the first imaging to sample a first image signal obtained by the first imaging and a timing of causing the sample/hold circuit in the second imaging to sample a second image signal obtained by the second imaging in accordance with radiation irradiation conditions set in advance so as to reduce a difference between an amount of noise contained in the first image signal and an amount of noise contained in the second image signal.

An X-ray detection device 30 comprises a low energy scintillator 31 configured to convert an X-ray of a low energy range into scintillation light, a low energy line sensor 32 configured to detect the scintillation light to output image data, a high energy scintillator 33 configured to convert an X-ray of a high energy range into scintillation light, and a high energy line sensor 34 configured to detect the scintillation light to output image data. Pixels L of the low energy line sensor 32 and pixels H of the high energy line sensor 34 are identical in number and are aligned at an identical pixel pitch, and a minimum filtering process is executed on the image data from the low energy line sensor 32, while an averaging process is executed on the image data from the high energy line sensor 34.

A method of determining at least one x-ray scanning system geometric property includes the steps of positioning a calibration device inside a scanning chamber of the scanning device, the chamber being intersected by at least one fan beam of x-rays during a scanning operation, measuring a distance between the calibration device and at least one inner wall of the chamber, scanning the calibration device to produce an image of the calibration device, identifying pixels representing the a geometric feature of the calibration device in the image, determining a position and orientation of the pixels representing the geometric feature in the image and, determining a scanning system property based on the position and orientation of the pixels representing the geometric feature in the image. The position and orientation of the feature in the scanning chamber and the x-ray scanning system property may be determined simultaneously.

A system for inspecting an object, includes: a source of X-ray radiation; a horizontal array of detectors, wherein the source and the array of detectors are positioned substantially on a first plane; a platform configured to rotate as well as translate in a vertical trajectory, wherein the platform is positioned on a second plane between the source and the array of detectors, and wherein the object is disposed on the platform; and a computing device configured to: cause the source to fire a substantially horizontal fan beam in a third plane, wherein the third plane is above a top of the object; acquire calibration data from the array of detectors while the third plane is above the top of the object; cause the platform to simultaneously rotate and raise the object vertically upwards; acquire scan data of the object; and generate a three dimensional scan image of the object.

A method of determining at least one x-ray scanning system geometric property includes the steps of positioning a calibration device inside a scanning chamber of the scanning device, the chamber being intersected by at least one fan beam of x-rays during a scanning operation, measuring a distance between the calibration device and at least one inner wall of the chamber, scanning the calibration device to produce an image of the calibration device, identifying pixels representing the a geometric feature of the calibration device in the image, determining a position and orientation of the pixels representing the geometric feature in the image and, determining a scanning system property based on the position and orientation of the pixels representing the geometric feature in the image. The position and orientation of the feature in the scanning chamber and the x-ray scanning system property may be determined simultaneously.

A method for assigning one of a safe and threat condition to an object includes determining density and effective atomic number values for a plurality of predetermined safe and threat objects, plotting the values in a probability map to correlate corresponding density and effective atomic number values with each of the safe and threat objects, scanning an object to provide dual-energy attenuation images representing the object, decomposing the attenuation images into dual-reference material equivalent path length images to provide reference material equivalent path lengths representing the object, converting the reference path lengths into object path lengths, determining the effective atomic number for each pixel representing the object, and, imposing the effective atomic number and the mass density of the unknown object onto the probability map to determine a probability that the object is correlated with one of the predetermined safe and threat objects.

There is provided a method for assigning an attribute to x-ray attenuation including the steps of acquiring first and second reference material equivalent path length information associated with a first range of dual-energy x-ray attenuation information, acquiring second and third reference material equivalent path length information associated with a second range of dual-energy x-ray attenuation information, and, joining the first the first dual-energy x-ray attenuation information range with the second dual-energy x-ray attenuation information range using coefficients representing dual-energy x-ray attenuation information of the second reference material to define a third dual-energy x-ray attenuation information range upon which may be imposed dual-energy x-ray attenuation values within the third dual-energy x-ray attenuation information range to determine corresponding first reference material equivalent path lengths and third reference material equivalent path lengths.

There is provided a method for assigning an attribute to x-ray attenuation including scanning in an x-ray scanning device first and second reference materials each having known atomic composition, dimensions and orientation in the scanning device. The device emits x-rays which pass through the first reference material with first reference material path lengths and the second reference material with second reference material path lengths. The x-rays are detected by detectors to provide a plurality of dual-energy attenuation images having dual-energy x-ray attenuation information. The dual-energy x-ray attenuation information in the dual-energy attenuation images is associated with the first and second reference material path lengths. Then, each of the first and second reference material path lengths are expressed collectively as a function of the associated attenuation information to define attenuation surfaces upon which may be imposed dual-energy attenuation values to determine corresponding first and second reference material equivalent path lengths.